Gøran Paulsen

• Andersen, Vidar; Paulsen, Gøran; Stien, Nicolay; Baarholm, Martin; Seynnes, Olivier R. & Sæterbakken, Atle Hole (2024). Resistance Training with Different Velocity Loss Thresholds Induce Similar Changes in Strength and Hypertrophy. Journal of Strength and Conditioning Research. ISSN 1064-8011. 38(3), s. E135–E142. doi: 10.1519/JSC.0000000000004067.
• Ryningen, Anita; Rostad, Kari; Ersvær, Elisabeth; Sjøholt, Gry; Paulsen, Gøran & Gundersen, Hilde [Vis alle 8 forfattere av denne artikkelen] (2024). Acute response in circulating microRNAs following a single bout of short-sprint and heavy strength training in well-trained cyclists. Frontiers in Physiology. ISSN 1664-042X. 15. doi: 10.3389/fphys.2024.1365357. Fulltekst i vitenarkiv
• Støvland, Varg Ringdal; Amundsen, Roar; Paulsen, Gøran & Dalen-Lorentsen, Torstein (2023). Prepare to fail or failing to prepare? Acute performance after the 11+ with and without strength exercises. BMJ Open sport & exercise medicine. ISSN 2055-7647. 9(4). doi: 10.1136/bmjsem-2023-001634. Fulltekst i vitenarkiv
• Nysether, Sondre; Hopkins, Will G.; Mentzoni, Fredrik; Paulsen, Gøran; Haugen, Thomas André & Solberg, Paul Andre (2023). Monitoring Changes in Lower-Limb Strength and Power in Elite Athletes With the Countermovement-Jump and Keiser Leg-Press Tests. International Journal of Sports Physiology and Performance (IJSPP). ISSN 1555-0265. 18(10), s. 1145–1151. doi: 10.1123/ijspp.2023-0088.
• Bobbert, Maarten F.; Lindberg, Kolbjørn Andreas; Bjørnsen, Thomas; Solberg, Paul Andre & Paulsen, Gøran (2023). The Force-Velocity Profile for Jumping: What It Is and What It Is Not. Medicine & Science in Sports & Exercise. ISSN 0195-9131. 55(7), s. 1241–1249. doi: 10.1249/MSS.0000000000003147. Fulltekst i vitenarkiv Vis sammendrag

  Introduction Force–velocity profiling has been proposed in the literature as a method to identify the overall mechanical characteristics of lower extremities. A force–velocity profile is obtained by plotting for jumps at different loads the effective work as a function of the average push-off velocity, fitting a straight line to the results, and extrapolating this line to find the theoretical maximum isometric force and unloaded shortening velocity. Here we investigated whether the force–velocity profile and its characteristics can be related to the intrinsic force–velocity relationship. Methods We used simulation models of various complexity, ranging from a simple mass actuated by a linearly damped force to a planar musculoskeletal model comprising four segments and six muscle–tendon complexes. The intrinsic force–velocity relationship of each model was obtained by maximizing the effective work during isokinetic extension at different velocities. Results Several observations were made. First, at the same average velocity, less effective work can be done during jumping than during isokinetic lower extremity extension at this velocity. Second, the intrinsic relationship is curved; fitting a straight line and extrapolating it seem arbitrary. Third, the maximal isometric force and the maximal velocity corresponding to the profile are not independent. Fourth, they both vary with inertial properties of the system. Conclusions For these reasons, we concluded that the force–velocity profile is specific for the task and is just what it is: the relationship between effective work and an arbitrary estimate of average velocity; it does not represent the intrinsic force–velocity relationship of the lower extremities.

• Myrholt, Roger Behrman; Solberg, Paul Andre; Pettersen, Henrik; Seynnes, Olivier R. & Paulsen, Gøran (2023). Effects of Low- Versus High-Velocity-Loss Thresholds With Similar Training Volume on Maximal Strength and Hypertrophy in Highly Trained Individuals. International Journal of Sports Physiology and Performance (IJSPP). ISSN 1555-0265. 18(4), s. 368–377. doi: 10.1123/ijspp.2022-0161. Vis sammendrag

  Aims: In the present intervention study, low-velocity-loss (LVL) versus high-velocity-loss (HVL) thresholds in the squat and bench press were compared for changes in muscle strength, power, and hypertrophy. Methods: Strength-trained volunteers (7♀ and 9♂; age: 27.2 [3.4] y; height: 174.6 [8.0] cm; body mass: 75.3 [10.1] kg) were randomized into an LVL or HVL threshold group (LVL n = 3♀ + 5♂, and HVL n = 4♀ + 4♂). Training took place 3 times per week over 6 weeks (loads: ∼75%–90% of 1-repetition maximum [1RM]). The thresholds of LVLs and HVLs were set at 20% and 40% of maximal velocity, respectively, for the squat, and at 30% and 60%, respectively, for the bench press. Before and after the intervention, 1RM, leg press power, and squat jump were tested. The load (∼45% of 1RM) corresponding to 1-m/s velocity was assessed in all sessions for both exercises. In addition, the thickness of the vastus lateralis and triceps brachii and body composition (dual-energy X-ray absorptiometry [DEXA]) were measured. Results: Squat and bench-press 1RM increased similarly in both groups by 7% to 11% (SD: 4%–6%, P < .05). No group differences were observed for changes in jump height, leg press power, or DEXA lean mass. However, HVL showed a small increase in muscle thickness of the vastus lateralis compared with LVL (6 ± 6% [95% CI] group difference, P < .05). Conclusion: For strength-trained individuals, high-volume lower-velocity-loss thresholds were as effective as higher thresholds for improvements in 1RM strength; but local hypertrophy was seemingly elicited faster with higher velocity-loss thresholds.

• Werkhausen, Amelie; Gløersen, Øyvind; Nordez, Antoine; Paulsen, Gøran; Bojsen-Møller, Jens & Seynnes, Olivier R. (2023). Linking muscle architecture and function in vivo: conceptual or methodological limitations? PeerJ. ISSN 2167-8359. 11. doi: 10.7717/peerj.15194. Fulltekst i vitenarkiv Vis sammendrag

  Background Despite the clear theoretical link between sarcomere arrangement and force production, the relationship between muscle architecture and function remain ambiguous in vivo. Methods: We used two frequently used ultrasound-based approaches to assess the relationships between vastus lateralis architecture parameters obtained in three common conditions of muscle lengths and contractile states, and the mechanical output of the muscle in twenty-one healthy subjects. The relationship between outcomes obtained in different conditions were also examined. Muscle architecture was analysed in panoramic ultrasound scans at rest with the knee fully extended and in regular scans at an angle close to maximum force (60°), at rest and under maximum contraction. Isokinetic and isometric strength tests were used to estimate muscle force production at various fascicle velocities. Results: Measurements of fascicle length, pennation angle and thickness obtained under different experimental conditions correlated moderately with each other (r = 0.40−.74). Fascicle length measured at 60° at rest correlated with force during high-velocity knee extension (r = 0.46 at 400° s−1) and joint work during isokinetic knee extension (r = 0.44 at 200° s−1 and r = 0.57 at 100° s−1). Muscle thickness was related to maximum force for all measurement methods (r = 0.44–0.73). However, we found no significant correlations between fascicle length or pennation angle and any measures of muscle force or work. Most correlations between architecture and force were stronger when architecture was measured at rest close to optimal length. Conclusion: These findings reflect methodological limitations of current approaches to measure fascicle length and pennation angle in vivo. They also highlight the limited value of static architecture measurements when reported in isolation or without direct experimental context.

• Lindberg, Kolbjørn Andreas; Bjørnsen, Thomas; Vårvik, Fredrik Tonstad; Paulsen, Gøran; Joensen, Malene & Kristoffersen, Morten [Vis alle 11 forfattere av denne artikkelen] (2023). The effects of being told you are in the intervention group on training results: a pilot study. Scientific Reports. ISSN 2045-2322. 13(1), s. 1–10. doi: 10.1038/s41598-023-29141-7. Fulltekst i vitenarkiv Vis sammendrag

  Little is known about the placebo effects when comparing training interventions. Consequently, we investigated whether subjects being told they are in the intervention group get better training results compared to subjects being told they are in a control group. Forty athletes (male: n = 31, female: n = 9) completed a 10-week training intervention (age: 22 ± 4 years, height: 183 ± 10 cm, and body mass: 84 ± 15 kg). After randomization, the participants were either told that the training program they got was individualized based on their force–velocity profile (Placebo), or that they were in the control group (Control). However, both groups were doing the same workouts. Measurements included countermovement jump (CMJ), 20-m sprint, one-repetition maximum (1RM) back-squat, a leg-press test, ultrasonography of muscle-thickness (m. rectus femoris), and a questionnaire (Stanford Expectations of Treatment Scale) (Younger et al. in Clin Trials 9(6):767–776, 2012). Placebo increased 1RM squat more than Control (5.7 ± 6.4% vs 0.9 ± 6.9%, [0.26 vs 0.02 Effect Size], Bayes Factor: 5.1 [BF10], p = 0.025). Placebo had slightly higher adherence compared to control (82 ± 18% vs 72 ± 13%, BF10: 2.0, p = 0.08). Importantly, the difference in the 1RM squat was significant after controlling for adherence (p = 0.013). No significant differences were observed in the other measurements. The results suggest that the placebo effect may be meaningful in sports and exercise training interventions. It is possible that ineffective training interventions will go unquestioned in the absence of placebo-controlled trials.

• Andersen, Vidar; Hermans, Espen ; Vereide, Vegard Albert; Stien, Nicolay; Paulsen, Gøran & Baláš, Jiří [Vis alle 9 forfattere av denne artikkelen] (2023). Comparison of finger flexor resistance training, with and without blood flow restriction, on perceptional and physiological responses in advanced climbers. Scientific Reports. ISSN 2045-2322. 13, s. 1–8. doi: 10.1038/s41598-023-30499-x. Fulltekst i vitenarkiv Vis sammendrag

  This study compared perceptional and physiological responses of finger flexor exercise performed with free flow and blood flow restriction (BFR). Thirteen male advanced climbers completed three sessions of finger flexor resistance exercise at (1) 40% of MVC (Low) and (2) 75% of MVC (High) and (3) BFR at 40% of MVC (Low + BFR) in a randomized and counterbalanced order. Rate of perceived exertion for effort (RPE) and discomfort (RPD), session pleasure/displeasure (sPDF), exercise enjoyment (EES), lactate concentration and oxygen saturation were recorded after the last set. Both low-intensity sessions induced higher RPD than High (p = 0.018–0.022, ES = 1.01–1.09) and High was perceived as more enjoyable than Low-BFR (p = 0.031, ES = 1.08). No differences were found for RPE or sPDF (p = 0.132–0.804). Lactate was elevated more after High than the Low-sessions (p < 0.001, ES = 1.88–2.08). Capillary oxygen saturation was lower after Low + BFR compared to the other sessions (p = 0.031, ES = 1.04–1.27). Finally, the exercise volume was greater in Low compared to High (p = 0.022, ES = 1.14) and Low + BFR (p = 0.020, ES = 0.77). In conclusion, among advanced male climbers, performing Low + BFR led to a similar exercise volume but was perceived as more discomforting and less enjoyable compared to High. The Low session yielded similar responses as the Low + BFR but required a much greater exercise volume.

• Werkhausen, Amelie; Gløersen, Øyvind Nøstdahl; Nordez, Antoine; Paulsen, Gøran; Bojsen-Møller, Jens & Seynnes, Olivier R. (2022). Rate of force development relationships to muscle architecture and contractile behavior in the human vastus lateralis. Scientific Reports. ISSN 2045-2322. 12(1). doi: 10.1038/s41598-022-26379-5. Fulltekst i vitenarkiv Vis sammendrag

  In this study, we tested the hypotheses that (i) rate of force development (RFD) is correlated to muscle architecture and dynamics and that (ii) force–length–velocity properties limit knee extensor RFD. Twenty-one healthy participants were tested using ultrasonography and dynamometry. Vastus lateralis optimal fascicle length, fascicle velocity, change in pennation angle, change in muscle length, architectural gear ratio, and force were measured during rapid fixed-end contractions at 60° knee angle to determine RFD. Isokinetic and isometric tests were used to estimate individual force–length–velocity properties, to evaluate force production relative to maximal potential. Correlation analyses were performed between force and muscle parameters for the first three 50 ms intervals. RFD was not related to optimal fascicle length for any measured time interval, but RFD was positively correlated to fascicle shortening velocity during all intervals (r = 0.49–0.69). Except for the first interval, RFD was also related to trigonometry-based changes in muscle length and pennation angle (r = 0.45–0.63) but not to architectural gear ratio. Participants reached their individual vastus lateralis force–length–velocity potential (i.e. their theoretical maximal force at a given length and shortening velocity) after 62 ± 24 ms. Our results confirm the theoretical importance of fascicle shortening velocity and force–length–velocity properties for rapid force production and suggest a role of fascicle rotation.

• Andersen, Vidar; Prieske, Olaf; Stien, Nicolay; Cumming, Kristoffer Toldnes; Solstad, Tom Erik Jorung & Paulsen, Gøran [Vis alle 9 forfattere av denne artikkelen] (2022). Comparing the effects of variable and traditional resistance training on maximal strength and muscle power in healthy adults: A systematic review and meta-analysis. Journal of Science and Medicine in Sport. ISSN 1440-2440. 25(12), s. 1023–1032. doi: 10.1016/j.jsams.2022.08.009. Fulltekst i vitenarkiv Vis sammendrag

  Objectives: The aim of the study was to aggregate different effects between variable resistance training and traditional resistance training on maximal muscle strength and muscle power and identify potential sex- and training program-related moderator variables. Design: Meta-analysis. Methods: A systematic literature search was conducted in SPORTDiscus, PubMed, and Web of Science. Interventions were included if they compared variable resistance training and traditional resistance training in healthy adults and examined the effects on measures of maximal muscle strength and/or muscle power of the lower and/or upper body. A random-effects model was used to calculate weighted and averaged standardized mean differences. Additionally, univariate sub-group analyses were independently computed for sex and training-related moderator variables. Results: Seventeen studies comprising a total of 491 participants (341 men and 150 women, age 18–37 years) were included in the analyses. In terms of maximal muscle strength, there were no statistically significant differences between variable resistance training and traditional resistance training for the lower (p = 0.46, standardized mean difference = −0.10) or the upper body (p = 0.14, standardized mean difference = −0.17). Additionally, there were no significant training-related differences in muscle power for the lower (p = 0.16, standardized mean difference = 0.21) or upper body (p = 0.81, standardized mean difference = 0.05). Sub-group analyses showed a significant moderator effect for training period and repetitions per set for maximal muscle strength in the lower body (p = 0.03–0.04) with larger strength gains following traditional resistance training when performing more repetitions per set (p = 0.02, standardized mean difference = 0.43). No other significant sub-group effects were found (p = 0.18–0.82). Conclusions: Our results suggest that variable resistance training and traditional resistance training are equally effective in improving maximal muscle strength and muscle power in healthy adults.

• Lindberg, Kolbjørn Andreas; Solberg, Paul Andre; Bjørnsen, Thomas; Helland, Christian; Rønnestad, Bent & Frank, Martin Thorsen [Vis alle 13 forfattere av denne artikkelen] (2022). Strength and Power Testing of Athletes: Associations of Common Assessments Over Time. International Journal of Sports Physiology and Performance (IJSPP). ISSN 1555-0265. 17(8), s. 1280–1288. doi: 10.1123/ijspp.2021-0557. Vis sammendrag

  Purpose: This study examined the associations among common assessments for measuring strength and power in the lower body of high-performing athletes, including both cross-sectional and longitudinal data. Methods: A total of 100 participants, including both male (n = 83) and female (n = 17) athletes (21 [4] y, 182 [9] cm, 78 [12] kg), were recruited for the study using a multicenter approach. The participants underwent physical testing 4 times. The first 2 sessions (1 and 2) were separated by ∼1 week, followed by a period of 2 to 6 months, whereas the last 2 sessions (3 and 4) were also separated by ∼1 week. The test protocol consisted of squat jumps, countermovement jumps, jump and reach, 30-m sprint, 1-repetition-maximum squat, sprint cycling, and a leg-press test. Results: There were generally acceptable correlations among all performance measures. Variables from the countermovement jumps and leg-press power correlated strongly with all performance assessments (r = .52–.79), while variables from sprint running and squat-jump power displayed more incoherent correlations (r = .21–.82). For changes over time, the correlations were mostly strong, albeit systematically weaker than for cross-sectional measures. Conclusions: The associations observed among the performance assessments seem to be consistent for both cross-sectional data and longitudinal change scores. The weaker correlations for change scores are most likely mainly caused by lower between-subjects variations in the change scores than for the cross-sectional data. The present study provides novel information, helping researchers and practitioners to better interpret the relationships across common performance assessment methods.

• Lindberg, Kolbjørn Andreas; Solberg, Paul Andre; Bjørnsen, Thomas; Helland, Christian; Rønnestad, Bent & Frank, Martin [Vis alle 13 forfattere av denne artikkelen] (2022). Strength and Power Testing of Athletes: A Multicenter Study of Test-Retest Reliability. International Journal of Sports Physiology and Performance (IJSPP). ISSN 1555-0265. 17(7), s. 1103–1110. doi: 10.1123/ijspp.2021-0558. Fulltekst i vitenarkiv Vis sammendrag

  Purpose:This study examined the test–retest reliability of common assessments for measuring strength and power of the lowerbody in high-performing athletes.Methods:A total of 100 participants, including both male (n=83) and female (n=17) athletes(21 [4] y, 182 [9] cm, and 78 [12] kg), were recruited for this study, using a multicenter approach. The participants underwentphysical testing 4 times. Thefirst 2 sessions (1 and 2) were separated by∼1 week, followed by a period of 2 to 6 months, whereasthe last 2 sessions (3 and 4) were again separated by∼1 week. The test protocol consisted of squat jumps, countermovementjumps, jump and reach, 30-m sprint, 1-repetition-maximum squat, sprint cycling, and a leg-press test.Results:The typical error(%) ranged from 1.3% to 8.5% for all assessments. The change in means ranged from−1.5% to 2.5% for all assessments, whereasthe interclass correlation coefficient ranged from .85 to .97. The smallest worthwhile change (0.2 of baseline SD) ranged from1.2% to 5.0%. The ratio between the typical error (%) and the smallest worthwhile change (%) ranged from 0.5 to 1.2. Whenobserving the reliability across testing centers, considerable differences in reliability were observed (typical error [%] ratio: 0.44–1.44).Conclusions:Most of the included assessments can be used with confidence by researchers and coaches to measurestrength and power in athletes. Our results highlight the importance of controlling testing reliability at each testing center and notrelying on data from others, despite having applied the same protocol.

• Lindberg, Kolbjørn Andreas; Lohne-Seiler, Hilde; Fosstveit, Sindre Herskedal; Sibayan, Erlend E.; Fjeller, Joachim S. & Løvold, Sondre [Vis alle 12 forfattere av denne artikkelen] (2022). Effectiveness of individualized training based on force–velocity profiling on physical function in older men. Scandinavian Journal of Medicine & Science in Sports. ISSN 0905-7188. 32(6), s. 1013–1025. doi: 10.1111/sms.14157. Fulltekst i vitenarkiv Vis sammendrag

  The study aimed to investigate the effectiveness of an individualized power training program based on force–velocity (FV) profiling on physical function, muscle morphology, and neuromuscular adaptations in older men. Forty-nine healthy men (68 ± 5 years) completed a 10-week training period to enhance muscular power. They were randomized to either a generic power training group (GPT) or an individualized power training group (IPT). Unlike generic training, individualized training was based on low- or high-resistance exercises, from an initial force–velocity profile. Lower-limb FV profile was measured in a pneumatic leg-press, and physical function was assessed as timed up-and-go time (TUG), sit-to-stand power, grip strength, and stair-climbing time (loaded [20kg] and unloaded). Vastus lateralis morphology was measured with ultrasonography. Rate of force development (RFD) and rate of myoelectric activity (RMA) were measured during an isometric knee extension. The GPT group improved loaded stair-climbing time (6.3 ± 3.8 vs. 2.3% ± 7.3%, p = 0.04) more than IPT. Both groups improved stair-climbing time, sit to stand, and leg press power, grip strength, muscle thickness, pennation angle, fascicle length, and RMA from baseline (p < 0.05). Only GPT increased loaded stair-climbing time and RFD (p < 0.05). An individualized power training program based on FV profiling did not improve physical function to a greater degree than generic power training. A generic power training approach combining both heavy and low loads might be advantageous through eliciting both force- and velocity-related neuromuscular adaptions with a concomitant increase in muscular power and physical function in older men.

• Rakovic, Elvir; Paulsen, Gøran; Helland, Christian; Haugen, Thomas André & Eriksrud, Ola (2022). Validity and Reliability of a Motorized Sprint Resistance Device. Journal of Strength and Conditioning Research. ISSN 1064-8011. 36(8), s. 2335–2338. doi: 10.1519/JSC.0000000000003830. Fulltekst i vitenarkiv Vis sammendrag

  An increasing number of sprint-related studies have used motorized devices to provide resistance while sprinting. The aim of this study was to establish within-session reliability and criterion validity of sprint times obtained from a motorized resistance device. Seventeen elite, female, handball players (22.9 ± 3.0 years; 176.5 ± 6.5 cm; 72.7 ± 5.5 kg; training volume 9.3 ± 0.7 hours per week) performed two 30-m sprints under 3 different resistance loading conditions (50, 80 and 110 N). Sprint times (t0–5m, t5–10m, t10–15m, t15–20m, t20–30m, and t0–30m) were assessed simultaneously by a 1080 Sprint motorized resistance device and a postprocessing timing system. The results showed that 1080 Sprint timing was equivalent to the postprocessing timing system within the limits of precision (±0.01 seconds). A systematic bias of approximately 0.34 ± 0.01 seconds was observed for t0–5m caused by different athlete location and velocity at triggering point between the systems. Coefficient of variation was approximately 2% for t0–5 and approximately 1% for the other time intervals, although standard error of measurement ranged from 0.01 to 0.05 seconds, depending on distance and phase of sprint. Intraclass correlation ranged from 0.86 to 0.95. In conclusion, the present study shows that the 1080 Sprint is valid and reliable for sprint performance monitoring purposes.

• Andersen, Vidar; Paulsen, Gøran; Stien, Nicolay; Baarholm, Martin; Seynnes, Olivier R. & Sæterbakken, Atle Hole (2021). Resistance Training With Different Velocity Loss Thresholds Induce Similar Changes in Strengh and Hypertrophy. Journal of Strength and Conditioning Research. ISSN 1064-8011. doi: 10.1519/JSC.0000000000004067. Vis sammendrag

  The aim of this study was to compare the effects of 2 velocity-based resistance training programs when performing resistance training with matched training volume. Ten resistance-trained adults volunteered (age, 23 ± 4.3 years; body mass, 68 ± 8.9 kg; and height, 171 ± 8 cm) with a mean resistance training experience of 4.5 years. A within person, between leg design was used. For each subject, the legs were randomly assigned to either low velocity loss (LVL) threshold at 15% or high velocity loss (HVL) threshold at 30% velocity loss. Leg press and leg extension were trained unilaterally twice per week over a period of 9 weeks. Before and after the intervention, both legs were tested in 1 repetition maximum (RM) (kg), maximal voluntary contraction (MVC) (N), rate of force development (N·s−1), average velocity (m·s−1), and power output (W) at 30, 45, 60, and 75% of 1 RM (all in unilateral leg press). Furthermore, muscle thickness (mm) of the vastus lateralis and rectus femoris, pennation angle (°) of the vastus lateralis, and the fascicle length (mm) of the vastus lateralis were measured using ultrasound imaging. The data were analyzed using mixed-design analysis of variance. No differences between the legs in any of the variables were found; however, both low and HVL were effective for increasing 1 RM (ES = 1.25–1.82), MVC (effect size [ES] = 0.42–0.64), power output (ES = 0.31–0.86), and muscle thickness (ES = 0.24–0.51). In conclusion, performing velocity-based resistance training with low and HVL with equal training volume resulted in similar effects in maximal and explosive strength in addition to muscular adaptations.

• Bjørnsen, Thomas; Wernbom, Mathias; Paulsen, Gøran; Markworth, James F.; Berntsen, Sveinung & D'Souza, Randall F. [Vis alle 8 forfattere av denne artikkelen] (2021). High-frequency blood flow-restricted resistance exercise results in acute and prolonged cellular stress more pronounced in type I than in type II fibers. Journal of applied physiology. ISSN 8750-7587. 131(2), s. 643–660. doi: 10.1152/japplphysiol.00115.2020. Vis sammendrag

  Myocellular stress with high-frequency blood flow-restricted resistance exercise (BFRRE) was investigated by measures of heat shock protein (HSP) responses, glycogen content, and inflammatory markers. Thirteen participants [age: 24 ± 2 yr (means ± SD), 9 males] completed two 5-day blocks of seven BFRRE sessions, separated by 10 days. Four sets of unilateral knee extensions to failure at 20% of one-repetition maximum (1RM) were performed. Muscle samples obtained before, 1 h after the first session in the first and second block (acute 1 and acute 2), after three sessions (day 4), during the “rest week,” and at 3 (post 3) and 10 days postintervention (post 10) were analyzed for HSP70, αB-crystallin, glycogen [periodic acid-Schiff (PAS) staining], mRNAs, miRNAs, and CD68+ (macrophages) and CD66b+ (neutrophils) cell numbers. αB-crystallin translocated from the cytosolic to the cytoskeletal fraction after acute 1 and acute 2 (P < 0.05) and immunostaining revealed larger responses in type I than in type II fibers (acute 1, 225 ± 184% vs. 92 ± 81%, respectively, P = 0.001). HSP70 was increased in the cytoskeletal fraction at day 4 and post 3, and immunostaining intensities were more elevated in type I than in type II fibers at day 4 (206 ± 84% vs. 72 ± 112%, respectively, P <0.001), during the rest week (98 ± 66% vs. 42 ± 79%, P < 0.001), and at post 3 (115 ± 82% vs. 28 ± 78%, P = 0.003). Glycogen content was reduced in both fiber types, but most pronounced in type I, which did not recover until the rest week (−15% to 29%, P ≤ 0.001). Intramuscular macrophage numbers were increased by ∼65% postintervention, but no changes were observed in muscle neutrophils. We conclude that high-frequency BFRRE with sets performed till failure stresses both fiber types, with type I fibers being most affected.

• Lindberg, Kolbjørn; Solberg, Paul; Rønnestad, Bent; Frank, Martin; Larsen, Tommy Mella & Abusdal, Gøran [Vis alle 11 forfattere av denne artikkelen] (2021). Should we individualize training based on force-velocity profiling to improve physical performance in athletes? Scandinavian Journal of Medicine & Science in Sports. ISSN 0905-7188. 31(12), s. 2198–2210. doi: 10.1111/sms.14044. Fulltekst i vitenarkiv Vis sammendrag

  The present study aimed to examine the effectiveness of an individualized training program based on force-velocity (FV) profiling on jumping, sprinting, strength, and power in athletes. Forty national level team sport athletes (20 ± 4years, 83 ± 13 kg) from ice-hockey, handball, and soccer completed a 10-week training intervention. A theoretical optimal squat jump (SJ)-FV-profile was calculated from SJ with five different loads (0, 20, 40, 60, and 80 kg). Based on their initial FV-profile, athletes were randomized to train toward, away, or irrespective (balanced training) of their initial theoretical optimal FV-profile. The training content was matched between groups in terms of set x repetitions but varied in relative loading to target the different aspects of the FV-profile. The athletes performed 10 and 30 m sprints, SJ and countermovement jump (CMJ), 1 repetition maximum (1RM) squat, and a leg-press power test before and after the intervention. There were no significant group differences for any of the performance measures. Trivial to small changes in 1RM squat (2.9%, 4.6%, and 6.5%), 10 m sprint time (1.0%, −0.9%, and −1.7%), 30 m sprint time (0.9%, −0.6%, and −0.4%), CMJ height (4.3%, 3.1%, and 5.7%), SJ height (4.8%, 3.7%, and 5.7%), and leg-press power (6.7%, 4.2%, and 2.9%) were observed in the groups training toward, away, or irrespective of their initial theoretical optimal FV-profile, respectively. Changes toward the optimal SJ-FV-profile were negatively correlated with changes in SJ height (r = −0.49, p < 0.001). Changes in SJ-power were positively related to changes in SJ-height (r = 0.88, p < 0.001) and CMJ-height (r = 0.32, p = 0.044), but unrelated to changes in 10 m (r = −0.02, p = 0.921) and 30 m sprint time (r = −0.01, p = 0.974). The results from this study do not support the efficacy of individualized training based on SJ-FV profiling.

• Haugen, Thomas André; Hopkins, Will G.; Breitschedel, Felix; Paulsen, Gøran & Solberg, Paul Andre (2021). Fitness Tests and Match Performance in a Male Ice Hockey National League. International Journal of Sports Physiology and Performance (IJSPP). ISSN 1555-0265. 16(9), s. 1303–1310. doi: 10.1123/IJSPP.2020-0644.
• Stenqvist, Thomas Birkedal; Melin, Anna Katarina; Garthe, Ina; Slater, Gary; Paulsen, Gøran & Iraki, Juma [Vis alle 8 forfattere av denne artikkelen] (2021). Prevalence of Surrogate Markers of Relative Energy Deficiency in Male Norwegian Olympic-Level Athletes. International Journal of Sport Nutrition & Exercise Metabolism. ISSN 1526-484X. 31(6), s. 497–506. doi: 10.1123/ijsnem.2020-0368. Fulltekst i vitenarkiv Vis sammendrag

  The syndrome of Relative Energy Deficiency in Sport (RED-S) includes wide-ranging effects on physiological and psychological functioning, performance, and general health. However, RED-S is understudied among male athletes at the highest performance levels. This cross-sectional study aimed to investigate surrogate RED-S markers prevalence in Norwegian male Olympic-level athletes. Athletes (n = 44) aged 24.7 ± 3.8 years, body mass 81.3 ± 15.9 kg, body fat 13.7% ± 5.8%, and training volume 76.1 ± 22.9 hr/month were included. Assessed parameters included resting metabolic rate (RMR), body composition, and bone mineral density by dual-energy X-ray absorptiometry and venous blood variables (testosterone, free triiodothyronine, cortisol, and lipids). Seven athletes (16%) grouped by the presence of low RMR (RMRratio < 0.90) (0.81 ± 0.07 vs. 1.04 ± 0.09, p < .001, effect size 2.6), also showed lower testosterone (12.9 ± 5.3 vs. 19.0 ± 5.3 nmol/L, p = .020) than in normal RMR group. In low RMRratio individuals, prevalence of other RED-S markers (—subclinical—low testosterone, low free triiodothyronine, high cortisol, and elevated low-density lipoprotein) was (N/number of markers): 2/0, 2/1, 2/2, 1/3. Low bone mineral density (z-score < −1) was found in 16% of the athletes, all with normal RMR. Subclinical low testosterone and free triiodothyronine levels were found in nine (25%) and two (5%) athletes, respectively. Subclinical high cortisol was found in 23% of athletes while 34% had elevated low-density lipoprotein cholesterol levels. Seven of 12 athletes with two or more RED-S markers had normal RMR. In conclusion, this study found that multiple RED-S markers also exist in male Olympic-level athletes. This highlights the importance of regular screening of male elite athletes, to ensure early detection and treatment of RED-S.

• Dahl, Even B.; Øygard, Eivind; Paulsen, Gøran; Rud, Bjarne & Losnegard, Thomas Johansen (2021). Morning Preconditioning Exercise Does Not Increase Afternoon Performance in Competitive Runners. International Journal of Sports Physiology and Performance (IJSPP). ISSN 1555-0265. 16(12), s. 1816–1823. doi: 10.1123/ijspp.2020-0747. Fulltekst i vitenarkiv Vis sammendrag

  Purpose: Preconditioning exercise is a widely used strategy believed to enhance performance later the same day. The authors examined the influence of preconditioning exercises 6 hours prior to a time-to-exhaustion (TTE) test during treadmill running. Methods: Ten male competitive runners (age = 26 [3] y, height = 184 [8] cm, weight = 73 [9] kg, maximum oxygen consumption = 72 [7] mL·kg−1·min−1) did a preconditioning session of running (RUN) or resistance exercise (RES) or no morning exercise (NoEx) in a randomized order, separated by >72 hours. The RUN consisted of 15 minutes of low-intensity running and 4 × 15 seconds at race pace (21–24 km·h−1) on a treadmill; RES involved 5 minutes of low-intensity running and 2 × 3 repetitions of isokinetic 1-leg shallow squats with maximal mobilization. Following a 6-hour break, electrically evoked force (m. vastus medialis), countermovement jump, running economy, and a TTE of approximately 2 minutes were examined. Results: Relative to NoEx, no difference was seen for RUN or RES in TTE (mean ± 95% CI: −1.3% ± 3.4% and −0.5% ± 6.0%) or running economy (0.2% ± 1.6% and 1.9% ± 2.7%; all Ps > .05). Jump height was not different for the RUN condition (1.0% ± 2.7%]) but tended to be higher in RES than in the NoEx condition (1.5% ± 1.6%, P = .07). The electrically evoked force tended to reveal low-frequency fatigue (reduced 20:50-Hz peak force ratio) only after RES compared to NoEx (−4.5% ± 4.6%, P = .06). Conclusion: The RUN or RES 6 hours prior to approximately 2 minutes of TTE running test did not improve performance in competitive runners.

• Rud, Bjarne; Øygard, Eivind; Dahl, Even B.; Paulsen, Gøran & Losnegard, Thomas Johansen (2021). The Effect of Resistance Exercise Priming in the Morning on Afternoon Sprint Cross-Country Skiing Performance. International Journal of Sports Physiology and Performance (IJSPP). ISSN 1555-0265. 16(12), s. 1786–1793. doi: 10.1123/ijspp.2020-0881. Vis sammendrag

  Purpose: We tested whether a single session of heavy-load resistance priming conducted in the morning improved double-poling (DP) performance in the afternoon. Methods: Eight national-level male cross-country skiers (mean [SD]: 23 [3] y, 184 [6] cm, 73 [7] kg, maximum oxygen consumption = 69 [6] mL·kg−1·min−1) carried out 2 days of afternoon performance tests. In the morning, 5 hours before tests, subjects were counterbalanced to either a session of 3 × 3 repetitions (approximately 85%–90% 1-repetition maximum) of squat and sitting pullover exercises or no exercise. The performance was evaluated in DP as time to exhaustion (TTE) (approximately 3 min) on a treadmill and 30-m indoor sprints before and after TTE (30-m DP pre/post). Furthermore, submaximal DP oxygen cost, countermovement jump, and isometric knee-extension force during electrical stimulation were conducted. Participants reported perceived readiness on test days. Results: Resistance exercise session versus no exercise did not differ for TTE (approximately 3 min above) (mean ± 95% confidence interval = 3.6% ± 6.0%; P = .29; effect size [ES], Cohen d = 0.27), 30-m DP pre (−0.56% ± 0.80%; P = .21; ES = 0.20), 30-m DP post (−0.18% ± 1.13%; P = .76; ES = 0.03), countermovement jump (−2.0% ± 2.8%; P = .21; ES = 0.12), DP oxygen cost (−0.13% ± 2.04%; P = .91; ES = 0.02), or perceived readiness (P ≥ .11). Electrical stimulation force was not different in contraction or relaxation time but revealed low-frequency fatigue in the afternoon for the resistance exercise session only (−12% [7%]; P = .01; ES = 1.3). Conclusion: A single session of heavy-load, low-volume resistance exercise in the morning did not increase afternoon DP performance of short duration in high-level skiers. However, leg low-frequency fatigue after resistance priming, together with the presence of small positive effects in 2 out of 3 DP tests, may indicate that the preconditioning was too strenuous.

• Losnegard, Thomas Johansen; Skarli, Sondre; Hansen, Joar; Roterud, Stian; Svendsen, Ida S. & Rønnestad, Bent [Vis alle 7 forfattere av denne artikkelen] (2021). Is Rating of Perceived Exertion a Valuable Tool for Monitoring Exercise Intensity During Steady-State Conditions in Elite Endurance Athletes? International Journal of Sports Physiology and Performance (IJSPP). ISSN 1555-0265. 16(11), s. 1589–1595. doi: 10.1123/ijspp.2020-0866. Fulltekst i vitenarkiv Vis sammendrag

  Purpose: Rating of perceived exertion (RPE) is a widely used tool to assess subjective perception of effort during exercise. The authors investigated between-subject variation and effect of exercise mode and sex on Borg RPE (6–20) in relation to heart rate (HR), oxygen uptake (VO2), and capillary blood lactate concentrations. Methods: A total of 160 elite endurance athletes performed a submaximal and maximal test protocol either during cycling (n = 84, 37 women) or running (n = 76, 32 women). The submaximal test consisted of 4 to 7 progressive 5-minute steps within ∼50% to 85% of maximal VO2. For each step, steady-state HR, VO2, and capillary blood lactate concentrations were assessed and RPE reported. An incremental protocol to exhaustion was used to determine maximal VO2 and peak HR to provide relative (%) HR and VO2 values at submaximal work rates. Results: A strong relationship was found between RPE and %HR, %VO2, and capillary blood lactate concentrations (r = .80–.82, all Ps < .05). The between-subject coefficient of variation (SD/mean) for %HR and %VO2 decreased linearly with increased RPE, from ∼10% to 15% at RPE 8 to ∼5% at RPE 17. Compared with cycling, running induced a systematically higher %HR and %VO2 (∼2% and 5%, respectively, P < .05) with these differences being greater at lower intensities (RPE < 13). At the same RPE, women showed a trivial, but significantly higher %HR and %VO2 than men (<1%, P < .05). Conclusions: Among elite endurance athletes, exercise mode influenced RPE at a given %HR and %VO2, with greater differences at lower exercise intensities. Athletes should manage different tools to evaluate training based on intensity and duration of workouts.

• Bjørnsen, Thomas; Wernbom, Mathias; Paulsen, Gøran; Berntsen, Sveinung; Brankovic, Robert & Stålesen, Håkon [Vis alle 8 forfattere av denne artikkelen] (2021). Frequent blood flow restricted training not to failure and to failure induces similar gains in myonuclei and muscle mass. Scandinavian Journal of Medicine & Science in Sports. ISSN 0905-7188. 31(7), s. 1420–1439. doi: 10.1111/sms.13952. Fulltekst i vitenarkiv Vis sammendrag

  The purpose of the present study was to compare the effects of short-term high-frequency failure vs non-failure blood flow–restricted resistance exercise (BFRRE) on changes in satellite cells (SCs), myonuclei, muscle size, and strength. Seventeen untrained men performed four sets of BFRRE to failure (Failure) with one leg and not to failure (Non-failure; 30-15-15-15 repetitions) with the other leg using knee-extensions at 20% of one repetition maximum (1RM). Fourteen sessions were distributed over two 5-day blocks, separated by a 10-day rest period. Muscle samples obtained before, at mid-training, and 10-day post-intervention (Post10) were analyzed for muscle fiber area (MFA), myonuclei, and SC. Muscle size and echo intensity of m.rectus femoris (RF) and m.vastus lateralis (VL) were measured by ultrasonography, and knee extension strength with 1RM and maximal isometric contraction (MVC) up until Post24. Both protocols increased myonuclear numbers in type-1 (12%–17%) and type-2 fibers (20%–23%), and SC in type-1 (92%–134%) and type-2 fibers (23%–48%) at Post10 (p < 0.05). RF and VL size increased by 5%–10% in both legs at Post10 to Post24, whereas the MFA of type-1 fibers in Failure was decreased at Post10 (−10 ± 16%; p = 0.02). Echo intensity increased by ~20% in both legs during Block1 (p < 0.001) and was ~8 to 11% below baseline at Post24 (p = 0.001–0.002). MVC and 1RM decreased by 5%–10% after Block1, but increased in both legs by 6%–11% at Post24 (p < 0.05). In conclusion, both short-term high-frequency failure and non-failure BFRRE induced increases in SCs, in myonuclei content, muscle size, and strength, concomitant with decreased echo intensity. Intriguingly, the responses were delayed and peaked 10–24 days after the training intervention. Our findings may shed light on the mechanisms involved in resistance exercise-induced overreaching and supercompensation.

• Werkhausen, Amelie; Solberg, Christian E.; Paulsen, Gøran; Bojsen-Møller, Jens & Seynnes, Olivier R. (2021). Adaptations to explosive resistance training with partial range of motion are not inferior to full range of motion. Scandinavian Journal of Medicine & Science in Sports. ISSN 0905-7188. 31(5), s. 1026–1035. doi: 10.1111/sms.13921. Vis sammendrag

  We tested whether explosive resistance training with partial range of motion (ROM) would be as effective as full ROM training using a noninferiority trial design. Fifteen subjects with strength training experience took part in an explosive—concentric only—leg press training program, three times per week for 10 weeks. One leg was randomly assigned to exercise with partial ROM (ie, 9º) and the other leg to full ROM. Before and after training, we assessed leg press performance, isokinetic concentric and isometric knee extension torque, and vastus lateralis muscle architecture. Overall, both training modalities increased maximal strength and rate of force development. Training with partial ROM yielded noninferior results compared to full ROM for leg press peak power (+69 ± 47% vs. +61 ± 64%), isokinetic strength (4-6 ± 6%-12% vs. 1-6 ± 6%-10% at 30, 60, and 180˚s-1), and explosive torque after 100 (47 ± 24 vs. 35 ± 22) and 150 ms (57 ± 22% vs. 42 ± 25%). The comparison was inconclusive for other functional parameters (ie, isokinetic peak torque (300˚s−1), joint angle at isokinetic peak torque, explosive torque after 50 ms, and electrically evoked torque) and for muscle fascicle length and thickness, although noninferiority was established for pennation angle. However, partial ROM was not found statistically inferior to full ROM for any measured variable. Under the present conditions, the effects of explosive heavy resistance training were independent of joint ROM. Instead, these data suggest that the distinct timing of muscle work in explosive contractions confers more influence to the starting joint angle than ROM on adaptations to this type of training.

• Koivisto-Mørk, Anu; Svendsen, Ida Siobhan; Skattebo, Øyvind; Hallén, Jostein & Paulsen, Gøran (2021). Impact of baseline serum ferritin and supplemental iron on altitude-induced hemoglobin mass response in elite athletes. Scandinavian Journal of Medicine & Science in Sports. ISSN 0905-7188. 31(9), s. 1764–1773. doi: 10.1111/sms.13982. Fulltekst i vitenarkiv Vis sammendrag

  The present study explored the impact of pre-altitude serum (s)-ferritin and iron supplementation on changes in hemoglobin mass (ΔHbmass) following altitude training. Measures of Hbmass and s-ferritin from 107 altitude sojourns (9–28 days at 1800–2500 m) with world-class endurance athletes (males n = 41, females n = 25) were analyzed together with iron supplementation and self-reported illness. Altitude sojourns with a hypoxic dose [median (range)] of 1169 (912) km·h increased Hbmass (mean ± SD) 36 ± 38 g (3.7 ± 3.7%, p < 0.001) and decreased s-ferritin −11 (190) µg·L−1 (p = 0.001). Iron supplements [27 (191) mg·day−1] were used at 45 sojourns (42%), while only 11 sojourns (10%) were commenced with s-ferritin <35 µg/L. Hbmass increased by 4.6 ± 3.7%, 3.4 ± 3.3%, 4.2 ± 4.3%, and 2.9 ± 3.4% with pre-altitude s-ferritin ≤35 µg·L−1, 36–50 µg·L−1, 51–100 µg·L−1, and >100 µg·L−1, respectively, with no group difference (p = 0.400). Hbmass increased by 4.1 ± 3.9%, 3.0 ± 3.0% and 3.7 ± 4.7% without, ≤50 mg·day−1 or >50 mg·day−1 supplemental iron, respectively (p = 0.399). Linear mixed model analysis revealed no interaction between pre-altitude s-ferritin and iron supplementation on ΔHbmass (p = 0.906). However, each 100 km·h increase in hypoxic dose augmented ΔHbmass by an additional 0.4% (95% CI: 0.1–0.7%; p = 0.012), while each 1 g·kg−1 higher pre-altitude Hbmass reduced ΔHbmass by −1% (−1.6 to −0.5; p < 0.001), and illness lowered ΔHbmass by −5.7% (−8.3 to −3.1%; p < 0.001). In conclusion, pre-altitude s-ferritin or iron supplementation were not related to the altitude-induced increase in Hbmass (3.7%) in world-class endurance athletes with clinically normal iron stores.

• Lindberg, Kolbjørn Andreas; Eythorsdottir, Ingrid Eir Thorp; Solberg, Paul Andre; Gløersen, Øyvind Nøstdahl; Seynnes, Olivier R. & Bjørnsen, Thomas [Vis alle 7 forfattere av denne artikkelen] (2021). Validity of Force–Velocity Profiling Assessed With a Pneumatic Leg Press Device. International Journal of Sports Physiology and Performance (IJSPP). ISSN 1555-0265. 16(12), s. 1777–1785. doi: 10.1123/ijspp.2020-0954. Fulltekst i vitenarkiv
• Bø, Kari; Haakstad, Lene Annette Hagen; Paulsen, Gøran & Rustaden, Anne Mette (2021). Does regular strength training cause urinary incontinence in overweight inactive women? : A randomized controlled trial. International Urogynecology Journal. ISSN 0937-3462. doi: 10.1007/s00192-021-04739-5. Fulltekst i vitenarkiv Vis sammendrag

  Introduction and hypothesis: Urinary incontinence (UI) is common in women who exercise. We aimed to investigate new onset UI in formerly inactive, overweight or obese women (BMI > 25) participating in three different strength training modalities compared with a non-exercising control group. Methods: This was a secondary analysis of an assessor blinded randomized controlled trial investigating the effect of 12 weeks of three strength training concepts for women on muscle strength and body composition. None of the programs included pelvic floor muscle training. International Consensus on Incontinence Questionnaire Urinary Incontinence Short Form (ICIQ-UI-SF) was used to investigate primary outcome; new onset UI, and secondary outcome; ICIQ-UI-SF sum score. Suissa and Shuster’s exact unconditional test was used to analyze difference in new onset UI. Difference in ICIQ-UI-SF sum score is presented as mean with 95% CI. Results: At baseline 40 out of 128 (31.2%) participants reported UI. Three out of 27, 2 out of 17, 2 out of 23, and 0 out of 21 women in the three training and control groups respectively had new onset UI. There were no statistically significant differences in new onset UI across the groups or when collapsing new onset UI in the intervention groups compared with the controls (7 out of 67 vs 0 out of 21), p = 0.124. After the intervention the control group reported worse ICIQ-UI-SF sum score than any of the training groups; mean difference − 6.6 (95% CI: −11.9, −1.27), p = 0.012, but there was no difference in change from baseline to 12 weeks between the groups p = 0.145). Conclusions: There was no statistically significant change in UI after strength training.

• Lindberg, Kolbjørn Andreas; Solberg, Paul; Bjørnsen, Thomas; Helland, Christian; Rønnestad, Bent & Frank, Martin Thorsen [Vis alle 12 forfattere av denne artikkelen] (2021). Force-velocity profiling in athletes: Reliability and agreement across methods. PLOS ONE. ISSN 1932-6203. 16(2). doi: 10.1371/journal.pone.0245791. Fulltekst i vitenarkiv Vis sammendrag

  The aim of the study was to examine the test-retest reliability and agreement across methods for assessing individual force-velocity (FV) profiles of the lower limbs in athletes. Using a multicenter approach, 27 male athletes completed all measurements for the main analysis, with up to 82 male and female athletes on some measurements. The athletes were tested twice before and twice after a 2- to 6-month period of regular training and sport participation. The double testing sessions were separated by ~1 week. Individual FV-profiles were acquired from incremental loading protocols in squat jump (SJ), countermovement jump (CMJ) and leg press. A force plate, linear encoder and a flight time calculation method were used for measuring force and velocity during SJ and CMJ. A linear regression was fitted to the average force and velocity values for each individual test to extrapolate the FV-variables: theoretical maximal force (F0), velocity (V0), power (Pmax), and the slope of the FV-profile (SFV). Despite strong linearity (R2>0.95) for individual FV-profiles, the SFV was unreliable for all measurement methods assessed during vertical jumping (coefficient of variation (CV): 14–30%, interclass correlation coefficient (ICC): 0.36–0.79). Only the leg press exercise, of the four FV-variables, showed acceptable reliability (CV:3.7–8.3%, ICC:0.82–0.98). The agreement across methods for F0 and Pmax ranged from (Pearson r): 0.56–0.95, standard error of estimate (SEE%): 5.8–18.8, and for V0 and SFV r: -0.39–0.78, SEE%: 12.2–37.2. With a typical error of 1.5 cm (5–10% CV) in jump height, SFV and V0 cannot be accurately obtained, regardless of the measurement method, using a loading range corresponding to 40–70% of F0. Efforts should be made to either reduce the variation in jumping performance or to assess loads closer to the FV-intercepts. Coaches and researchers should be aware of the poor reliability of the FV-variables obtained from vertical jumping, and of the differences across measurement methods.

• Gjestvang, Christina; Stensrud, Trine; Paulsen, Gøran & Haakstad, Lene Annette Hagen (2021). Stay true to your workout: Does repeated physical testing boost exercise attendance? A one-year follow-up study. Journal of Sports Science and Medicine. ISSN 1303-2968. 20(1), s. 35–44. doi: 10.52082/jssm.2021.35. Fulltekst i vitenarkiv
• Helland, Christian; Midttun, Magnus; Sæland, Fredrik; Haugvad, Lars; Olstad, Daniela Schäfer & Solberg, Paul Andre [Vis alle 7 forfattere av denne artikkelen] (2020). A strength-oriented exercise session required more recovery time than a power-oriented exercise session with equal work. PeerJ. ISSN 2167-8359. 8. doi: 10.7717/peerj.10044. Fulltekst i vitenarkiv Vis sammendrag

  The present randomized cross-over controlled study aimed to compare the rate of recovery from a strength-oriented exercise session vs. a power-oriented session with equal work. Sixteen strength-trained individuals conducted one strength-oriented session (five repetitions maximum (RM)) and one power-oriented session (50% of 5RM) in randomized order. Squat jump (SJ), countermovement jump (CMJ), 20-m sprint, and squat and bench press peak power and estimated 1RMs were combined with measures of rate of perceived exertion (RPE) and perceived recovery status (PRS), before, immediately after and 24 and 48 h after exercise. Both sessions induced trivial to moderate performance decrements in all variables. Small reductions in CMJ height were observed immediately after both the strength-oriented session (7 ± 6%) and power-oriented session (5 ± 5%). Between 24 and 48 h after both sessions CMJ and SJ heights and 20 m sprint were back to baseline. However, in contrast to the power-oriented session, recovery was not complete 48 h after the strength-oriented session, as indicated by greater impairments in CMJ eccentric and concentric peak forces, SJ rate of force development (RFD) and squat peak power. In agreement with the objective performance measurements, RPE and PRS ratings demonstrated that the strength-oriented session was experienced more strenuous than the power-oriented session. However, these subjective measurements agreed poorly with performance measurements at the individual level. In conclusion, we observed a larger degree of neuromuscular impairment and longer recovery times after a strength-oriented session than after a power-oriented session with equal total work, measured by both objective and subjective assessments. Nonetheless, most differences were small or trivial after either session. It appears necessary to combine several tests and within-test analyses (e.g., CMJ height, power and force) to reveal such differences. Objective and subjective assessments of fatigue and recovery cannot be used interchangeably; rather they should be combined to give a meaningful status for an individual in the days after a resistance exercise session.

• Trøen, Erik; Rud, Bjarne; Karlsson, Øyvind; Carlsen, Camilla Høivik; Gilgien, Matthias & Paulsen, Gøran [Vis alle 8 forfattere av denne artikkelen] (2020). Pole Length’s Influence on Performance During Classic-Style Snow Skiing in Well-Trained Cross-Country Skiers. International Journal of Sports Physiology and Performance (IJSPP). ISSN 1555-0265. 15(6), s. 884–891. doi: 10.1123/ijspp.2019-0310. Fulltekst i vitenarkiv Vis sammendrag

  Purpose: To investigate how self-selected pole length (PL) of ∼84% (PL84%) compared with ∼90% (PL90%) of body height influenced performance during a 700-m time trial with undulating terrain on snow. Methods: Twenty-one cross-country skiers, 7 of whom were women, performed 4 trials at a maximal effort in a counterbalanced fashion with PL84% and PL90% separated by 20-minute breaks between trials. In trials I and II, only double poling was allowed, while in trials III and IV, skiers used self-selected classical subtechniques. Continuous speed, cyclic parameters, and heart rate were collected using microsensors in addition to a post-time-trial rating of perceived exertion (RPE). Results: The 700-m times with only double poling were significantly shorter with PL90% than PL84% (mean ± 95% confidence limits –1.6% ± 1.0%). Segment analyses showed higher speed with PL90% in uphill sections than with PL84% (3.7% ± 2.1%), with the greatest difference found for the female skiers (5.6% ± 2.9%). In contrast, on flat terrain at high skiing speeds, speed was reduced with PL90% compared with PL84% (–1.5% ± 1.4%); this was only significant for the male skiers. During free choice of classical subtechniques, PL did not influence performance in any segments, choice of subtechnique, or cycle rate during the trials. No differences in rating of perceived exertion or heart rate between PLs were found. Conclusions: PL90% improved performance in uphills at low speeds when using double poling but hindered performance on flat terrain and at higher speeds compared with self-selected PLs. Choice of PL should, therefore, be based on racecourse topography, preferred subtechniques, and the skier’s physiological and technical abilities.

• Koivisto-Mørk, Anu; Paur, Ingvild; Paulsen, Gøran; Garthe, Ina; Raastad, Truls & Bastani, Nasser Ezzatkhah [Vis alle 8 forfattere av denne artikkelen] (2020). Dietary Adjustments to Altitude Training in Elite Endurance Athletes; Impact of a Randomized Clinical Trial With Antioxidant-Rich Foods. Frontiers in Sports and Active Living. ISSN 2624-9367. 2. doi: 10.3389/fspor.2020.00106. Fulltekst i vitenarkiv Vis sammendrag

  Background: Altitude training stresses several physiological and metabolic processes and alters the dietary needs of the athletes. International Olympic Committee (IOC)'s Nutrition Expert Group suggests that athletes should increase intake of energy, carbohydrate, iron, fluid, and antioxidant-rich foods while training at altitude. Objective: We investigated whether athletes adjust their dietary intake according to the IOC's altitude-specific dietary recommendations, and whether an in-between meal intervention with antioxidant-rich foods altered the athletes' dietary composition and nutrition-related blood parameters (mineral, vitamin, carotenoid, and hormone concentrations). Design: The dietary adjustments to altitude training (3 weeks at 2,320 m) were determined for 31 elite endurance athletes (23 ± 5 years, 23 males, 8 females) by six interviewer-administered 24-h dietary recalls on non-consecutive days; three before and during the altitude camp. The additional effect of in -between meal intervention with eucaloric antioxidant-rich or control snacks (1,000 kcal/day) was tested in a randomized controlled trial with parallel design. Results: At altitude the athletes increased their energy intake by 35% (1,430 ± 630 kcal/day, p < 0.001), the provided snacks accounting for 70% of this increase. Carbohydrate intake increased from 6.5 ± 1.8 g/kg body weight (BW) (50 E%) to 9.3 ± 2.1 g/kg BW (53 E%) (p < 0.001), with no difference between the antioxidant and control group. Dietary iron, fluid, and antioxidant-rich food intake increased by 37, 38, and 104%, respectively, in the whole cohort. The intervention group had larger increases in polyunsaturated fatty acids (PUFA), ω3 PUFA (n-3 fatty acids), ω6 PUFA (n-6 fatty acids), fiber, vitamin C, folic acid, and copper intake, while protein intake increased more among the controls, reflecting the nutritional content of the snacks. Changes in the measured blood minerals, vitamins, and hormones were not differentially affected by the intervention except for the carotenoid; zeaxanthin, which increased more in the intervention group (p < 0.001). Conclusions: Experienced elite endurance athletes increased their daily energy, carbohydrate, iron, fluid, and antioxidant-rich food intake during a 3-week training camp at moderate altitude meeting most of the altitude-specific dietary recommendations. The intervention with antioxidant-rich snacks improved the composition of the athletes' diets but had minimal impact on the measured nutrition-related blood parameters.

• Shaw, Matthew Peter; Andersen, Vidar; Sæterbakken, Atle Hole; Paulsen, Gøran; Samnøy, Lars Edvin & Solstad, Tom Erik Jorung (2020). Contemporary Training Practices of Norwegian Powerlifters. Journal of Strength and Conditioning Research. ISSN 1064-8011. 36(9), s. 2544–2551. doi: 10.1519/JSC.0000000000003584.
• Rustaden, Anne Mette; Gjestvang, Christina; Bø, Kari; Haakstad, Lene Annette Hagen & Paulsen, Gøran (2020). Similar Energy Expenditure During BodyPump and Heavy Load Resistance Exercise in Overweight Women. Frontiers in Physiology. ISSN 1664-042X. 11. doi: 10.3389/fphys.2020.00570. Fulltekst i vitenarkiv Vis sammendrag

  Purpose: High-repetition, low-load resistance exercise in group class settings has gained popularity in recent years, with BodyPump as a prime example. For individuals using exercise for body-weight management, the energy expenditure during exercise is of interest. Therefore, we herein aimed to estimate the energy expenditure during a session of BodyPump and a time-matched session of heavy load resistance training in overweight women (BMI ≥ 25.0). Methods: Eighteen women participated in the study (mean age 35.4 years ± 10.2, BMI 30.4 kg/m2 ± 4.8), 10 exercising BodyPump (50–100 repetitions each muscle group) and eight performed a heavy load session (eight repetition maximum × three sets). The energy expenditure was assessed with indirect calorimetry during the sessions and for two intervals at rest during the recovery phase: 0–20 and 120–140 min after the sessions. Results: The BodyPump group lifted significantly more loads than the heavy load group (19,485 kg ± 2258 vs 15,616 kg ± 2976, p = 0.006), while energy expenditure was similar with 302 kcal ± 67 and 289 kcal ± 69 in BodyPump and heavy load group, respectively (p = 0.69). With no group differences, the resting metabolic rate (RMR) was elevated with 15–22% 2 h after exercise. Conclusion: Overweight women achieved an energy expenditure of approximately 300 kcal (4.7 kcal per min) during a single session of BodyPump, which was similar with the women performing a single session of heavy load resistance exercise.

• McGhie, David; Østerås, Sindre; Ettema, Gertjan; Paulsen, Gøran & Sandbakk, Øyvind (2020). Strength Determinants of Jump Height in the Jump Throw Movement in Women Handball Players. Journal of Strength and Conditioning Research. ISSN 1064-8011. 34(10), s. 2937–2946. doi: 10.1519/JSC.0000000000002684. Fulltekst i vitenarkiv
• Wernbom, M.; Paulsen, Gøran; Bjørnsen, Thomas; Cumming, Kristoffer Toldnes & Raastad, Truls (2019). Risk of Muscle Damage With Blood Flow–Restricted Exercise Should Not Be Overlooked. Clinical Journal of Sports Medicine. ISSN 1050-642X. 00(00). doi: 10.1097/JSM.0000000000000755.
• Paulsen, Gøran & Benestad, Haakon Breien (2019). Muskelstolhet og rabdomyolyse. Tidsskrift for Den norske legeforening. ISSN 0029-2001. 139(10). doi: 10.4045/tidsskr.18.0727. Vis sammendrag

  In this clinical review, we propose an alternative mechanism for the pain associated with muscle soreness and compare it to the mechanisms underlying muscle injuries and rhabdomyolysis. This is based on our own experience of research in the field, as well as recent cellular and molecular studies in animal models selected from our personal archives and identified through unstructured searches.

• Losnegard, Thomas Johansen; Tosterud, Ola Kristoffer; Trøen, Erik; Carlsen, Camilla Høivik; Paulsen, Gøran & Rud, Bjarne (2019). The influence of pole lengths on O2-cost, kinematics, and performance in double poling at high speeds before and after a training period with long poles. European Journal of Applied Physiology. ISSN 1439-6319. 119(11-12), s. 2579–2587. doi: 10.1007/s00421-019-04237-z. Fulltekst i vitenarkiv Vis sammendrag

  Purpose: Previous studies have found an acute performance improvement with longer pole lengths in double poling (DP) at low-to-moderate speeds. We investigated the influence of pole lengths (PL) on O2-cost, 3D kinematics, and performance in DP at moderate-to-high speeds before (Pre) and after (Post) eight training sessions with long poles on a rollerski treadmill. Methods: Seven male and four female skiers completed tests with two different PLs (84 and 90% of body height). Submaximal O2-cost (1º; 4.5 [females] or 6 m s−1 [males]) and a peak velocity test (1º; ∼  7.3 m s−1) were assessed before and after a six week training period. The training sessions consisted of 50 min of low-moderate intensity training and 4 × 10 s maximal sprints with PL90%. Results: On average for all tests, PL84% induced 1.0 ± 1.0% higher peak velocity compared to PL90% (mean ± CI) with no difference in vertical displacement of center of mass (COMz). From Pre to Post, peak velocity and cycle time were increased and the displacement of COMz were reduced similarly for both PLs. At moderate speed, PL90% induced less displacement of COMz with subsequent 1.1 ± 0.7% lower O2-cost compared to PL84%. From Pre to Post, the O2-cost and COMz were reduced similarly for both PLs. Conclusions: Longer PL than skiers self-selected lengths reduce O2-cost at moderate speeds, but induced lower peak velocity. Eight sessions of training with PL90% did not influence the difference between PL84% and PL90% on O2-cost, kinematics or peak velocity.

• Werkhausen, Amelie Corinna; Cronin, Neil J; Albracht, Kirsten; Paulsen, Gøran; Larsen, Askild V. & Bojsen-Møller, Jens [Vis alle 7 forfattere av denne artikkelen] (2019). Training-induced increase in Achilles tendon stiffness affects tendon strain pattern during running. PeerJ. ISSN 2167-8359. 2019(4). doi: 10.7717/peerj.6764. Fulltekst i vitenarkiv Vis sammendrag

  Background: During the stance phase of running, the elasticity of the Achilles tendon enables the utilisation of elastic energy and allows beneficial contractile conditions for the triceps surae muscles. However, the effect of changes in tendon mechanical properties induced by chronic loading is still poorly understood. We tested the hypothesis that a training-induced increase in Achilles tendon stiffness would result in reduced tendon strain during the stance phase of running, which would reduce fascicle strains in the triceps surae muscles, particularly in the mono-articular soleus. Methods: Eleven subjects were assigned to a training group performing isometric single-leg plantarflexion contractions three times per week for ten weeks, and another ten subjects formed a control group. Before and after the training period, Achilles tendon stiffness was estimated, and muscle-tendon mechanics were assessed during running at preferred speed using ultrasonography, kinematics and kinetics. Results: Achilles tendon stiffness increased by 18% (P < 0.01) in the training group, but the associated reduction in strain seen during isometric contractions was not statistically significant. Tendon elongation during the stance phase of running was similar after training, but tendon recoil was reduced by 30% (P < 0.01), while estimated tendon force remained unchanged. Neither gastrocnemius medialis nor soleus fascicle shortening during stance was affected by training. Discussion: These results show that a training-induced increase in Achilles tendon stiffness altered tendon behaviour during running. Despite training-induced changes in tendon mechanical properties and recoil behaviour, the data suggest that fascicle shortening patterns were preserved for the running speed that we examined. The asymmetrical changes in tendon strain patterns supports the notion that simple in-series models do not fully explain the mechanical output of the muscle-tendon unit during a complex task like running.

• Solberg, Paul Andre; Hopkins, Will G.; Paulsen, Gøran & Haugen, Thomas André (2019). Peak age and performance progression in world-class weightlifting and powerlifting athletes. International Journal of Sports Physiology and Performance (IJSPP). ISSN 1555-0265. 14(10), s. 1357–1363. doi: 10.1123/ijspp.2019-0093.
• Sunde, Arnstein; Johansen, Jan-Michael; Gjøra, Martin; Paulsen, Gøran; Bråten, Morten & Helgerud, Jan [Vis alle 7 forfattere av denne artikkelen] (2019). Stronger Is Better: The Impact of Upper Body Strength in Double Poling Performance. Frontiers in Physiology. ISSN 1664-042X. 10, s. 1–11. doi: 10.3389/fphys.2019.01091. Fulltekst i vitenarkiv Vis sammendrag

  The purpose of the present study was to compare time results from a roller-skiing double poling (DP) time trial with different physiological variables, muscular strength variables, and DP characteristics in both male and female young competitive skiers with the same relative training background. In order to do this, 28 (16 women and 12 men) well-trained 16–25-year-old cross-country skiers from three Norwegian high schools for skiers, as well as local high performance competitive skiers from the South-East of Norway were recruited to participate in the study. All participants were tested for; maximal oxygen uptake in running, Peak oxygen uptake in DP, lactate threshold in DP, DP economy, time to voluntary exhaustion in DP, force analyses in DP, one repetition maximum and power output in pulldown, and leg press and a time trial during DP roller skiing. The results expressed strong correlations between roller skiing time trial performance and maximal strength in pull-down, both independent (rxy = −0.83, p < 0.01) and dependent (rxy–z = −0.50, p < 0.02) of sex. Higher maximal upper body strength was related to higher DP peak forces (PF) (rxy = 0.78, p < 0.02), lower DP frequency (rxy = −0.71, p < 0.01), and shorter DP contact time (CT) (rxy = −0.48, p < 0.02). The practical implications of the present study is to acknowledge maximal upper body strength as a performance determining factor in DP. This point at the importance of including maximal strength training in cross-country skiers training programs.

• Hott, Alexandra Christine; Brox, Jens Ivar; Pripp, Are Hugo; Juel, Niels Gunnar; Paulsen, Gøran & Liavaag, Sigurd (2019). Effectiveness of Isolated Hip Exercise, Knee Exercise, or Free Physical Activity for Patellofemoral Pain: A Randomized Controlled Trial. American Journal of Sports Medicine. ISSN 0363-5465. 47(6), s. 1312–1322. doi: 10.1177/0363546519830644.
• Koivisto, Anu; Olsen, Thomas; Paur, Ingvild; Paulsen, Gøran; Bastani, Nasser Ezzatkhah & Garthe, Ina [Vis alle 10 forfattere av denne artikkelen] (2019). Effects of antioxidant-rich foods on altitude-induced oxidative stress and inflammation in elite endurance athletes: A randomized controlled trial. PLOS ONE. ISSN 1932-6203. 14(6). doi: 10.1371/journal.pone.0217895. Fulltekst i vitenarkiv Vis sammendrag

  Background Various altitude training regimes, systematically used to improve oxygen carrying capacity and sports performance, have been associated with increased oxidative stress and inflammation. We investigated whether increased intake of common antioxidant-rich foods attenuates these processes. Methods In a randomized controlled trial, 31 elite endurance athletes (23 ± 5 years), ingested antioxidant-rich foods (n = 16), (> doubling their usual intake), or eucaloric control foods (n = 15) during a 3-week altitude training camp (2320 m). Fasting blood and urine samples were collected 7 days pre-altitude, after 5 and 18 days at altitude, and 7 days post-altitude. Change over time was compared between the groups using mixed models for antioxidant capacity [uric acid-free (ferric reducing ability of plasma (FRAP)], oxidative stress (8-epi-PGF2α) and inflammatory biomarkers (IFNγ, IL1α, IL1RA, IL1β, IL2, IL5, IL6, IL7, IL10, IL12p70, IL13, IL17, TNFα, MCP-1 and micro-CRP). The cytokine response to a stress-test (VO2max ramp test or 100 m swimming) was assessed at pre- and post-altitude. Results FRAP increased more in the antioxidant compared to the control group (p = 0.034). IL13 decreased in the antioxidant group, while increasing in the controls (p = 0.006). A similar trend was seen for IL6 (p = 0.062). A larger decrease in micro-CRP was detected in the antioxidant group compared to controls (β: -0.62, p = 0.02). We found no group differences for the remaining cytokines. 8-epi-PGF2α increased significantly in the whole population (p = 0.033), regardless group allocation. The stress response was significantly larger post-altitude compared with pre-altitude for IL1β, IL6, IL7, IL13, IL12p70 and TNFα, but we found no group differences. Conclusions Increased intake of antioxidant-rich foods elevated the antioxidant capacity and attenuated some of the altitude-induced systemic inflammatory biomarkers in elite athletes. The antioxidant intervention had no impact on the altitude-induced oxidative stress or changes in acute cytokine responses to exercise stress-tests.

• Paulsen, Gøran; Eidsheim, Hedda; Helland, Christian; Seynnes, Olivier R.; Solberg, Paul Andre & Rønnestad, Bent (2019). Eccentric cycling does not improve cycling performance in amateur cyclists. PLOS ONE. ISSN 1932-6203. 14:e0208452(1), s. 1–15. doi: 10.1371/journal.pone.0208452. Fulltekst i vitenarkiv Vis sammendrag

  Eccentric cycling training induces muscle hypertrophy and increases joint power output in non-athletes. Moreover, eccentric cycling can be considered a movement-specific type of strength training for cyclists, but it is hitherto unknown if eccentric cycling training can improve cycling performance in trained cyclists. Twenty-three male amateur cyclists were randomized to an eccentric or a concentric cycling training group. The eccentric cycling was performed at a low cadence (~40 revolution per minute) and the intensity was controlled by perceived effort (12–17 on the Borgs scale) during 2 min intervals (repeated 5–8 times). The cadence and perceived effort of the concentric group matched those of the eccentric group. Additionally, after the eccentric or concentric cycling, both groups performed traditionally aerobic intervals with freely chosen cadence in the same session (4–5 x 4–15 min). The participants trained twice a week for 10 weeks. Maximal oxygen uptake (VO2max), maximal aerobic power output (Wmax), lactate threshold, isokinetic strength, muscle thickness, pedaling characteristics and cycling performance (6- and 30-sec sprints and a 20-min time trial test) were assessed before and after the intervention period. Inferences about the true value of the effects were evaluated using probabilistic magnitude-based inferences. Eccentric cycling induced muscle hypertrophy (2.3 ± 2.5% more than concentric) and augmented eccentric strength (8.8 ± 5.9% more than concentric), but these small magnitude effects seemed not to transfer into improvements in the physiological assessments or cycling performance. On the contrary, the eccentric training appeared to have limiting or detrimental effects on cycling performance, measured as Wmax and a 20-min time trial. In conclusion, eccentric cycling training did not improve cycling performance in amateur cyclists. Further research is required to ascertain whether the present findings reflect an actual lack of efficacy, negative effects or a delayed response to eccentric cycling training.

• Helland, Christian; Haugen, Thomas André; Rakovic, Elvir; Eriksrud, Ola; Seynnes, Olivier R. & Mero, Antti A. [Vis alle 7 forfattere av denne artikkelen] (2019). Force–velocity profiling of sprinting athletes: single-run vs. multiple-run methods. European Journal of Applied Physiology. ISSN 1439-6319. 119(2), s. 465–473. doi: 10.1007/s00421-018-4045-2. Vis sammendrag

  Purpose: This study explored the agreement between a single-run and a multiple-run method for force–velocity (Fv) profiling of sprinting athletes; we evaluated both absolute values and changes over time caused by sprint training. Methods: Seventeen female handball players (23 ± 3 years, 177 ± 7 cm, 73 ± 6 kg) performed 30 m un-resisted and resisted sprints (50, 80 and 110 N resistance) before and after an 8-week sprint training intervention. Two approaches were used to calculate theoretical maximal velocity (v0), horizontal force (F0), power (Pmax), and the force–velocity slope (SFv): (1) the single-run method, based on inverse dynamics applied to the centre-of-mass movement, was calculated from anthropometric and sprint split time data; and (2) the multiple-run method, where peak velocity from un-resisted and resisted sprints were plotted against the horizontal resistances. Results: Trivial differences in v0 (0.7%) were observed between the two calculation methods. Corresponding differences for F0, Pmax and SFv were 16.4, 15.6 and 17.6%, respectively (most likely; very large effect size). F0 showed poor agreement between the methods (r = 0.26 and 0.16 before and after the intervention). No substantial correlation between the changes (from pre- to post-training tests) in SFV calculated with the single-run and the multiple-run methods were observed (r = 0.02). Conclusions: This study revealed poor agreement between the Fv relationships of the investigated calculation methods. In practice, both methods may have a purpose, but the single-run and the multiple-run methods appear to measure somewhat different sprint properties and cannot be used interchangeably.

• Horwath, Oscar; Paulsen, Gøran; Esping, Tobias; Seynnes, Olivier R. & Olsson, Monica Charlotte (2019). Isokinetic resistance training combined with eccentric overload improves athletic performance and induces muscle hypertrophy in young ice hockey players. Journal of Science and Medicine in Sport. ISSN 1440-2440. doi: 10.1016/j.jsams.2018.12.017. Fulltekst i vitenarkiv Vis sammendrag

  Objectives: To determine the combined effects of slow isokinetic resistance training and eccentric overload and compare it to traditional resistance training on strength, power, body composition and muscle hypertrophy in young ice hockey players. Design: Experimental, randomized trial. Methods: Twenty-two resistance-trained ice hockey players (18 ± 1 year) were assigned to either isokinetic resistance training and eccentric overload (ISO/ECC; n = 11) or traditional resistance training (TRAD; n = 11). Participants underwent supervised progressive resistance training for 8 weeks (2–3 sessions/week) involving lower body multiple-joint exercises (heavy squats and explosive jump squats). The ISO/ECC group performed their training using a computerized robotic engine system (1080 Quantum synchro, Sweden), whereas the TRAD group performed the same resistance exercises with isotonic loading. Before and after the intervention, participants were evaluated in 1RM back squat, loaded jump squats, sprint- and jump performance, body composition and muscle thickness using ultrasound measurement. Results: Similar moderate increases in 1RM back squat and power output in the jump squats were found in both the ISO/ECC and TRAD groups (11–17%, P < 0.01), whereas only the ISO/ECC group showed improvements in drop jump performance (9.8%, P = 0.01). Moreover, similar trivial changes in body composition were observed in both groups, while only the ISO/ECC training group increased muscle thickness in the vastus intermedius (P = 0.01) and rectus femoris muscles (P = 0.03). Conclusions: Both modalities effectively increased maximal strength and power output, whereas isokinetic resistance training, combined with eccentric overload, improved drop jump performance and induced greater muscle hypertrophy than traditional training in young ice hockey players.

• Rustaden, Anne Mette; Haakstad, Lene Annette Hagen; Paulsen, Gøran & Bø, Kari (2019). Does low and heavy load resistance training affect musculoskeletal pain in overweight and obese women? Secondary analysis of a randomized controlled trial. Brazilian Journal of Physical Therapy. ISSN 1413-3555. doi: 10.1016/j.bjpt.2019.01.005. Fulltekst i vitenarkiv Vis sammendrag

  Background: Overweight and obesity are associated with musculoskeletal pain, particularly in the female population. However, regular resistance training may positively affect these complaints. Objective: The present study aimed to investigate between group differences in musculoskeletal pain in previously inactive women, allocated to three different resistance-training modalities available in health- and fitness clubs. Methods: This is secondary analysis from a single-blinded randomized controlled trial, including healthy women (aged 18–65) with a BMI (kg/m2) ≥25. The participants were allocated to 12 weeks (3 times/weekly) of either BodyPump (high-repetition low-load group session) (n = 24), heavy load resistance training with a personal trainer (n = 28), non-supervised heavy load resistance training (n = 19) or non-exercising controls (n = 21). Primary outcome was self-reported musculoskeletal pain in ten different body parts, measured with the Standardized Nordic Pain Questionnaire, at baseline and post-test. In addition, the study included sub-analyses of the participants when they were divided into high (≥28 of 36 sessions, n = 38) and low (≤27 of 36 sessions, n = 22) exercise adherence. Results: The analysis revealed no between group differences in musculoskeletal pain in any of the ten body parts. The results did not change when the participants were divided into high versus low adherence. Conclusions: Twelve weeks of BodyPump, heavy load resistance training with a personal trainer and non-supervised heavy load resistance training did not show any effect on self-reported musculoskeletal pain in overweight women.

• Bjørnsen, Thomas; Wernbom, Mathias; Løvstad, Amund T.; Paulsen, Gøran; D'Souza, Randall F & Cameron-Smith, David [Vis alle 10 forfattere av denne artikkelen] (2018). Delayed myonuclear addition, myofiber hypertrophyand increases in strength with frequent low-load blood flow restricted training to volitional failure. Journal of applied physiology. ISSN 8750-7587. doi: 10.1152/japplphysiol.00397.2018. Vis sammendrag

  PURPOSE: To investigate muscle hypertrophy, strength, myonuclear and satellite cell (SC) responses to high-frequency blood flow restricted resistance exercise (BFRRE). METHODS: Thirteen individuals (24±2 years [mean ± SD], 9 males) completed two 5-day-blocks of 7 BFRRE sessions, separated by a 10-day rest period. Four sets of unilateral knee extensions to voluntary failure at 20% of 1RM were conducted with partial blood flow restriction (90-100 mmHg). Muscle samples obtained before-, during, 3- and 10 days after training were analyzed for muscle fiber area (MFA), myonuclei, SC, and mRNA and miRNA expression. Muscle size was measured by ultrasonography and magnetic resonance imaging, and strength with 1RM knee-extension. RESULTS: With the first block of BFRRE, SC number increased in both fiber types (70-80%, p<0.05), while type I and II MFA decreased by 6±7% and 15±11% (p<0.05), respectively. With the second block of training, muscle size increased by 6-8%, while the number of SC (type I: 80±63%, type II 147±95%), myonuclei (type I: 30±24%, type II: 31±28%) and MFA (type I: 19±19%, type II: 11±19%) peaked 10 days after the second block of BFRRE, whereas strength peaked after 20 days of detraining (6±6%, p<0.05). Pax7- and p21 mRNA expression were elevated during the intervention, while myostatin, IGF1R, MyoD, myogenin, cyclinD1 and -D2 mRNA did not change until 3-10 days post intervention. CONCLUSION: High frequency low-load BFRRE induced robust increases in SC, myonuclei and muscle size, but modest strength gains. Intriguingly, the responses were delayed and peaked 10-20 days after the training intervention, indicating overreaching.

• Hamarsland, Håvard; Aas, Sigve Nyvik; Nordengen, Anne Lene; Holte, Kari; Garthe, Ina & Paulsen, Gøran [Vis alle 10 forfattere av denne artikkelen] (2018). Native whey induces similar post exercise muscle anabolic responses as regular whey, despite greater leucinemia, in elderly individuals. The Journal of Nutrition, Health & Aging. ISSN 1279-7707. doi: 10.1007/s12603-018-1105-6. Fulltekst i vitenarkiv Vis sammendrag

  Objective: Elderly muscle seems less sensitive to the anabolic stimulus of a meal. Changes in blood concentrations of leucine are suggested as one important trigger of the anabolic response in muscle. The aim of this study was to investigate whether native whey protein, containing high amounts of leucine, may be a more potent stimulator of muscle protein synthesis (MPS) in elderly than regular whey protein (WPC-80) or milk. Design: Randomized controlled partial crossover. Setting: Norwegian School of Sport Sciences. Participants: 21 healthy elderly men and women (≥70 years). Intervention: Participants received either 20 g of WPC-80 and native whey (n = 11) on separate days in a crossover design, or milk (n = 10). Supplements were ingested immediately and two hours after a bout of lower body heavy-load resistance exercise. Measurements: Blood samples and muscle biopsies were collected to measure blood concentrations of amino acids by gas-chromatography mass spectrometry (GCMS), phosphorylation of p70S6K, 4E-BP1 and eEF-2 by immunoblotting and mixed muscle fractional synthetic rate (FSR) by use of [2H5]phenylalanine-infusion, GCMS and isotope-ratio mass spectrometry. Results: Native whey increased blood leucine concentrations more than WPC-80 (P < 0.05), but not p70S6K phosphorylation or mixed muscle FSR. Both whey supplements increased blood leucine concentrations (P < 0.01) and P70S6K phosphorylation more than milk (P = 0.014). Native whey reached higher mixed muscle FSR values than milk (P = 0.026) 1-3h after exercise. Conclusions: Despite greater increases in blood leucine concentrations than WPC-80 and milk, native whey was only superior to milk concerning increases in MPS and phosphorylation of P70S6K during a 5-hour post-exercise period in elderly individuals.

• Ihalainen, Johanna K.; Peltonen, Heikki; Paulsen, Gøran; Ahtiainen, Juha P.; Taipale, Ritva S & Hämäläinen, Mari [Vis alle 8 forfattere av denne artikkelen] (2018). Inflammation status of healthy young men: initial and specific responses to resistance training. Applied Physiology, Nutrition and Metabolism. ISSN 1715-5312. 43(3), s. 252–258. doi: 10.1139/apnm-2017-0315. Vis sammendrag

  Our primary aim was to study the effects of a 4-week preparatory resistance-training (RT) period followed by 12 weeks of 2 specific RT protocols (either hypertrophic-strength (HS) or strength-hypertrophy-power training) on inflammation markers and the possible relationship of the changes in abdominal fat and lean mass to the changes in inflammation status. A total of 82 healthy men were included in the study. Maximal concentric leg press strength (1-repetition maximum), total body lean mass, total body and abdominal fat mass, circulating high-sensitivity C-reactive protein, interleukin-6, interleukin-1 receptor antagonist (IL-1ra), monocyte chemoattractant protein 1 (MCP-1), and selected adipocytokines (resistin, adiponectin, and leptin) concentrations were measured before and after 4 (wk4) and 16 weeks (wk16) of RT. After the initial phase of RT, on wk4, abdominal and total fat mass as well as plasma leptin concentrations were significantly reduced (p < 0.05), whereas muscle mass, IL-1ra, resistin, and MCP-1 concentrations were significantly increased (p < 0.05). During specialized training phase, at wk16, only HS led to further reduction in abdominal and total fat mass, resistin, and leptin (p < 0.05), whereas both training modes led to lower MCP-1 concentrations (p < 0.05). Abdominal fat mass and circulating leptin were reduced already after 4 weeks of RT. Simultaneously, circulating MCP-1 and resistin concentrations increased, possibly as markers of muscle adaptation and regeneration. The present findings also suggest that RT with hypertrophic focus is beneficial for further reductions in abdominal fat mass and to decrease circulating inflammatory markers.

• Werkhausen, Amelie Corinna; Albracht, Kirsten; Cronin, Neil J; Paulsen, Gøran; Bojsen-Møller, Jens & Seynnes, Olivier R. (2018). Effect of training-induced changes in Achilles tendon stiffness on muscle-tendon behavior during landing. Frontiers in Physiology. ISSN 1664-042X. 9. doi: 10.3389/fphys.2018.00794. Vis sammendrag

  During rapid deceleration of the body, tendons buffer part of the elongation of the muscle–tendon unit (MTU), enabling safe energy dissipation via eccentric muscle contraction. Yet, the influence of changes in tendon stiffness within the physiological range upon these lengthening contractions is unknown. This study aimed to examine the effect of training-induced stiffening of the Achilles tendon on triceps surae muscle–tendon behavior during a landing task. Twenty-one male subjects were assigned to either a 10-week resistance-training program consisting of single-leg isometric plantarflexion (n = 11) or to a non-training control group (n = 10). Before and after the training period, plantarflexion force, peak Achilles tendon strain and stiffness were measured during isometric contractions, using a combination of dynamometry, ultrasound and kinematics data. Additionally, testing included a step-landing task, during which joint mechanics and lengths of gastrocnemius and soleus fascicles, Achilles tendon, and MTU were determined using synchronized ultrasound, kinematics and kinetics data collection. After training, plantarflexion strength and Achilles tendon stiffness increased (15 and 18%, respectively), and tendon strain during landing remained similar. Likewise, lengthening and negative work produced by the gastrocnemius MTU did not change detectably. However, in the training group, gastrocnemius fascicle length was offset (8%) to a longer length at touch down and, surprisingly, fascicle lengthening and velocity were reduced by 27 and 21%, respectively. These changes were not observed for soleus fascicles when accounting for variation in task execution between tests. These results indicate that a training-induced increase in tendon stiffness does not noticeably affect the buffering action of the tendon when the MTU is rapidly stretched. Reductions in gastrocnemius fascicle lengthening and lengthening velocity during landing occurred independently from tendon strain. Future studies are required to provide insight into the mechanisms underpinning these observations and their influence on energy dissipation.

• Rakovic, Elvir; Paulsen, Gøran; Helland, Christian; Eriksrud, Ola & Haugen, Thomas (2018). The effect of individualised sprint training in elite female team sport athletes: A pilot study. Journal of Sports Sciences. ISSN 0264-0414. 36(24), s. 2802–2808. doi: 10.1080/02640414.2018.1474536. Fulltekst i vitenarkiv Vis sammendrag

  This study aimed to evaluate whether an individualised sprint-training program was more effective in improving sprint performance in elite team-sport players compared to a generalised sprint-training program. Seventeen elite female handball players (23 ± 3 y, 177 ± 7 cm, 73 ± 6 kg) performed two weekly sprint training sessions over eight weeks in addition to their regular handball practice. An individualised training group (ITG, n = 9) performed a targeted sprint-training program based on their horizontal force-velocity profile from the pre-training test. Within ITG, players displaying the lowest, highest and mid-level force-velocity slope values relative to body mass were assigned to a resisted, an assisted or a mixed sprint-training program (resisted sprinting in the first half and assisted sprinting in the second half of the intervention period), respectively. A control group (CG, n = 8) performed a generalised sprint-training program. Both groups improved 30-m sprint performance by ~1% (small effect) and maximal velocity sprinting by ~2% (moderate effect). Trivial or small effect magnitudes were observed for mechanical outputs related to horizontal force- or power production. All between-group differences were trivial. In conclusion, individualised sprint-training was no more effective in improving sprint performance than a generalised sprint-training program.

• Hamarsland, Håvard; Paulsen, Gøran; Solberg, Paul Andre; Slaathaug, Ole Gunnar & Raastad, Truls (2018). Depressed Physical Performance Outlasts Hormonal Disturbances after Military Training. Medicine & Science in Sports & Exercise. ISSN 0195-9131. 50(10), s. 2076–2084. doi: 10.1249/MSS.0000000000001681. Fulltekst i vitenarkiv Vis sammendrag

  . Introduction: The aim of this study was to investigate the effect of an arduous 1-wk military course on measures of physical performance, body composition, and blood biomarkers. Methods: Participants were apprentices in an annual selection course for the Norwegian Special Forces. Fifteen soldiers (23 T 4 yr, 1.81 T 0.06 m, 78 T 7 kg) completed a hell week consisting of rigorous activity only interspersed by 2 to 3 h of sleep per day. Testing was conducted before and 0, 1, 3, 7, and 14 d after the hell week. Physical performance was measured as muscle strength and jump performance. Body composition was measured by bioelectrical impedance and blood samples were collected and analyzed for hormones, creatine kinase, and C-reactive protein. Results: Body mass was reduced by 5.3 T 1.9 kg during the hell week and returned to baseline within 1 wk. Fat mass was reduced by 2.1 T 1.7 kg and muscle mass by 1.9 T 0.9 kg. Muscle strength in leg press and bench press was reduced by 20% T 9% and 9% T 7%, respectively, and both were approximately 10% lower than baseline after 1 wk of recovery. Jump-height was reduced by 28% T 13% and was still 14% T 5% below baseline after 2 wk of recovery. Testosterone was reduced by 70% T 12% and recovered gradually within a week. Cortisol was increased by 154% T 74% and did not fully recover during the next week. Insulin-like growth factor 1 was reduced by 51% T 10% and triiodothyronine and thyroxine by 12% to 30%, all recovered within a week. Conclusions: One-week arduous military exercise resulted in reductions in body mass and performance, as well as considerable hormonal disturbances. Our most important observation was that whereas the hormonal systems was normalized within 1 wk of rest and proper nutrition, lower body strength and jump performance were still depressed after 2 wk.

• Ihalainen, Johanna K.; Schumann, Moritz; Eklund, Daniela; Hämäläinen, Mari; Moilanen, Eeva & Paulsen, Gøran [Vis alle 8 forfattere av denne artikkelen] (2018). Combined aerobic and resistance training decreases inflammation markers in healthy men. Scandinavian Journal of Medicine & Science in Sports. ISSN 0905-7188. 28(1), s. 40–47. doi: 10.1111/sms.12906. Vis sammendrag

  Our primary aim was to study the effects of 24 weeks of combined aerobic and resistance training performed on the same day or on different days on inflammation markers. Physically active, healthy young men were randomly divided into three groups that performed: aerobic and resistance training consecutively in the same training session (SS) 2‐3 days wk−1 or on alternating days (AD) 4‐6 days wk−1 as well as control (C). The total training volume was matched in the training groups. The control group was asked to maintain their habitual physical activity and exercise level. Maximal leg press strength (1RM) and peak oxygen uptake (VO2peak) were measured. Abdominal fat mass was estimated with dual‐energy absorptiometry (DXA). High‐sensitivity C‐reactive protein (hs‐CRP), interleukin‐6 (IL‐6), monocyte chemoattractant protein 1 (MCP‐1), tumor necrosis factor alpha (TNF‐α), and adipocytokines resistin, adiponectin, and leptin were analyzed from plasma samples. Training significantly reduced circulating hs‐CRP, leptin, and resistin in both training groups (P<.05), whereas MCP‐1 and TNF‐α decreased only in AD (P<.05). Significant correlations were observed between changes in abdominal fat mass and corresponding changes in MCP‐1, leptin, adiponectin, and resistin. Long‐term combined aerobic and resistance training reduced markers of subclinical inflammation in healthy young men. The results indicate that a higher frequency of individual exercise sessions might be more beneficial with respect to the anti‐inflammatory effects of physical activity. The decreases in inflammation markers seem to be related to decreases in abdominal fat mass.

• Hentila, Jaakko; Ahtiainen, Juha P.; Paulsen, Gøran; Raastad, Truls; Häkkinen, Keijo & Mero, Antti A. [Vis alle 7 forfattere av denne artikkelen] (2018). Autophagy is induced by resistance exercise in young men, but unfolded protein response is induced regardless of age. Acta Physiologica. ISSN 1748-1708. 224(1). doi: 10.1111/apha.13069. Vis sammendrag

  Aim: Autophagy and unfolded protein response (UPR) appear to be important for skeletal muscle homoeostasis and may be altered by exercise. Our aim was to investigate the effects of resistance exercise and training on indicators of UPR and autophagy in healthy untrained young men (n = 12, 27 ± 4 years) and older men (n = 8, 61 ± 6 years) as well as in resistance‐trained individuals (n = 15, 25 ± 5 years). Methods: Indicators of autophagy and UPR were investigated from the muscle biopsies after a single resistance exercise bout and after 21 weeks of resistance training. Results: Lipidated LC3II as an indicator of autophagosome content increased at 48 hours post‐resistance exercise (P < .05) and after a resistance training period (P < .01) in untrained young men but not in older men. Several UPRER markers, typically induced by protein misfolding in endoplasmic reticulum, were increased at 48 hours post‐resistance exercise in untrained young and older men (P < .05) but were unaltered after the 21‐week resistance training period regardless of age. UPR was unchanged within the first few hours after the resistance exercise bout regardless of the training status. Changes in autophagy and UPRER indicators did not correlate with a resistance training‐induced increase in muscle strength and size. Conclusion: Autophagosome content is increased by resistance training in young previously untrained men, but this response may be blunted by ageing. However, unfolded protein response is induced by an unaccustomed resistance exercise bout in a delayed manner regardless of age.

• Bjørnsen, Thomas; Wernbom, Mathias; Kirketeig, Alexander; Paulsen, Gøran; Samnøy, Lars Edvin & Bækken, Lasse Vestli [Vis alle 9 forfattere av denne artikkelen] (2018). Type 1 muscle fiber hypertrophy after blood flow–restricted training in Powerlifter. Medicine & Science in Sports & Exercise. ISSN 0195-9131. 51(2), s. 288–298. doi: 10.1249/MSS.0000000000001775. Fulltekst i vitenarkiv Vis sammendrag

  PURPOSE: To investigate the effects of blood flow restricted resistance exercise (BFRRE) on myofiber areas (MFA), number of myonuclei and satellite cells (SC), muscle size and strength in powerlifters. METHODS Seventeen national level powerlifters (25+/-6 yrs [mean+/-SD], 15 men) were randomly assigned to either a BFRRE group (n=9) performing two blocks (week 1 and 3) of five BFRRE front squat sessions within a 6.5-week training period, or a conventional training group (Con; n=8) performing front squats at ~70% of one-repetition maximum (1RM). The BFRRE consisted of four sets (first and last set to voluntary failure) at ~30% of 1RM. Muscle biopsies were obtained from m. vastus lateralis (VL) and analyzed for MFA, myonuclei, SC and capillaries. Cross sectional areas (CSA) of VL and m. rectus femoris (RF) were measured by ultrasonography. Strength was evaluated by maximal voluntary isokinetic torque (MVIT) in knee extension and 1RM in front squat. RESULTS: BFRRE induced selective type I fiber increases in MFA (BFRRE: 12% vs. Con: 0%, p<0.01) and myonuclear number (BFRRE: 17% vs. Con: 0%, p=0.02). Type II MFA was unaltered in both groups. BFRRE induced greater changes in VL CSA (7.7% vs. 0.5%, p=0.04), which correlated with the increases in MFA of type I fibers (r=0.81, p=0.02). No group differences were observed in SC and strength changes, although MVIT increased with BFRRE (p=0.04), whereas 1RM increased in Con (p=0.02). CONCLUSION Two blocks of low-load BFRRE in the front squat exercise resulted in increased quadriceps CSA associated with preferential hypertrophy and myonuclear addition in type 1 fibres of national level powerlifters.

• Koivisto, Anu; Paulsen, Gøran; Paur, Ingvild; Garthe, Ina; Tønnessen, Espen & Raastad, Truls [Vis alle 10 forfattere av denne artikkelen] (2018). Antioxidant-rich foods and response to altitude training: A randomized controlled trial in elite endurance athletes. Scandinavian Journal of Medicine & Science in Sports. ISSN 0905-7188. 28(9), s. 1982–1995. doi: 10.1111/sms.13212. Vis sammendrag

  High doses of isolated antioxidant supplements such as vitamin C and E have demonstrated the potential to blunt cellular adaptations to training. It is, however, unknown whether intake of high doses of antioxidants from foods has similar effects. Hence, the aim of the study was to investigate whether intake of antioxidant‐rich foods affects adaptations to altitude training in elite athletes. In a randomized controlled trial, 31 national team endurance athletes (23 ± 5 years) ingested antioxidant‐rich foods (n = 16) or eucaloric control foods (n = 15) daily during a 3‐week altitude training camp (2320 m). Changes from baseline to post‐altitude in hemoglobin mass (Hbmass; optimized CO rebreathing), maximal oxygen uptake (VO2max; n = 16) or 100 m swimming performance (n = 10), and blood parameters were compared between the groups. The antioxidant group significantly increased total intake of antioxidant‐rich foods (~118%) compared to the control group during the intervention. The total study population improved VO2max by 2.5% (1.7 mL/kg/min, P = .006) and Hbmass by 4.7% (48 g, P < .001), but not 100 m swimming performance. No difference was found between the groups regarding changes in Hbmass, VO2max or swimming performance. However, hemoglobin concentration increased more in the antioxidant group (effect size = 0.7; P = .045) with a concomitantly larger decrease in plasma and blood volumes compared to control group. Changes in ferritin and erythropoietin from pre‐ to post‐altitude did not differ between the groups. Doubling the intake of antioxidant‐rich foods was well tolerated and did not negatively influence the adaptive response to altitude training in elite endurance athletes.

• Haugen, Thomas André; Paulsen, Gøran; Seiler, Stephen & Sandbakk, Øyvind (2018). New records in human power. International Journal of Sports Physiology and Performance (IJSPP). ISSN 1555-0265. 13(6), s. 678–686. doi: 10.1123/ijspp.2017-0441. Fulltekst i vitenarkiv
• Cumming, Kristoffer Toldnes; Raastad, Truls; Sørstrøm, Andreas Natvig; Paronetto, Maria Paola; Mercatelli, Neri & Ugelstad, Ingrid [Vis alle 8 forfattere av denne artikkelen] (2017). Vitamin C and E supplementation does not affect heat shock proteins or endogenous antioxidants in trained skeletal muscles during 12 weeks of strength training. BMC Nutrition. ISSN 2055-0928. 3. doi: 10.1186/s40795-017-0185-8. Fulltekst i vitenarkiv Vis sammendrag

  Background: Supplementation with large doses of antioxidants, such as vitamin C and E, has been shown to blunt some adaptations to endurance training. The effects of antioxidant supplementation on adaptations to strength training is sparsely studied. Herein we investigated the effects of vitamin C and E supplementation on acute stress responses to exercise and adaptation to traditional heavy load strength training. Methods: In a double blind placebo-controlled design, twenty-eight, young, trained males and females were randomly assigned to receive either vitamin C and E (C: 1000 mg, E: 235 mg, per day) or placebo supplements, and underwent strength training for 10 weeks. After five weeks, a subgroup conducted a strength training session to investigate acute stress responses. Muscle samples were obtained to investigate changes in stress responses and in proteins and mRNA related to the heat shock proteins (HSPs) or antioxidant enzymes. Results: The acute responses to the exercise session revealed activation of the NFκB pathway indicated by degradation of IκBα in both groups. Vitamin C and E supplementation had, however, no effects on the acute stress responses. Furthermore, ten weeks of strength training did not change muscle αB-crystallin, HSP27, HSP70, GPx1 or mnSOD levels, with no influence of supplementation. Conclusions: Our results showed that although vitamin C and E supplementation has been shown to interfere with training adaptations, it did not affect acute stress responses or long-term training adaptations in the HSPs or antioxidant enzymes in this study.

• Ihalainen, Johanna K.; Ahtiainen, Juha P.; Walker, Simon; Paulsen, Gøran; Selänne, Harri & Hämäläinen, Mari [Vis alle 9 forfattere av denne artikkelen] (2017). Resistance training status modifies inflammatory response to explosive and hypertrophic resistance exercise bouts. Journal of physiology and biochemistry. ISSN 1138-7548. 73(4), s. 595–604. doi: 10.1007/s13105-017-0590-0. Vis sammendrag

  The purpose of the present study was to examine the immediate and prolonged immune response in circulating cytokine and adipocytokine concentrations after two different resistance exercise bouts: hypertrophic (HYP1, 5 × 10, 80% of 1RM) and maximal explosive (POW1, 10 × 5, 60% of 1RM) resistance exercise bouts and how 12 weeks of resistance training (RT) modifies these responses (HYP2, POW2). Eight men completed the study. RE-induced interleukin-6 (IL-6), interleukin-1β (IL-1β), interleukin-1 receptor antagonist (IL-1ra), monocyte-chemoattractant protein-1 (MCP-1), leptin, resistin, and adiponectin were measured before (PRE) and immediately (POST0), 24 (POST24) and 48 (POST48) hours after RE bouts before and after RT. In the untrained state, IL-6 increased immediately after RE in HYP1 (p = 0.002) and in POW1 (p = 0.003) whereas no changes were observed after RT. Similar results were observed in IL-1β, whereas conversely, IL-1ra increased only after RT in HYP2 and POW2 (p < 0.05). Resistin increased before RT in HYP1 and in POW1 (p = 0.011 and p = 0.003, respectively), but after RT, significant responses were not observed. Interestingly, in HYP2, MCP-1 increased significantly at POST24 (p = 0.009) and at POST48 (p = 0.032) only following RT. The present study shows that RT modifies RE-induced cytokine responses towards an anti-inflammatory direction.

• Øfsteng, Sjur Johansen; Sandbakk, Øyvind; Van Beekvelt, Mireille; Hammarström, Daniel; Kristoffersen, Roger & Hansen, Joar [Vis alle 8 forfattere av denne artikkelen] (2017). Strength training improves double-poling performance after prolonged submaximal exercise in cross-country skiers. Scandinavian Journal of Medicine & Science in Sports. ISSN 0905-7188. 28(3), s. 893–904. doi: 10.1111/sms.12990. Fulltekst i vitenarkiv Vis sammendrag

  The purpose of this study was to investigate the effects of adding strength training with or without vibration to cross-country (XC) skiers' endurance training on double-poling (DP) performance, physiological, and kinematic adaptations. Twenty-one well-trained male XC-skiers combined endurance- and upper-body strength training three times per week, either with (n = 11) or without (n = 10) superimposed vibrations for 8 weeks, whereas eight skiers performed endurance training only (CON). Testing included 1RM in upper-body exercises, work economy, neural activation, oxygen saturation in muscle, and DP kinematics during a prolonged submaximal DP roller ski test which was directly followed by a time to exhaustion (TTE) test. TTE was also performed in rested state, and the difference between the two TTE tests (TTEdiff ) determined the ability to maintain DP performance after prolonged exercise. Vibration induced no additional effect on strength or endurance gains. Therefore, the two strength training groups were pooled (STR, n = 21). 1RM in STR increased more than in CON (P < .05), and there were no differences in changes between STR and CON in any measurements during prolonged submaximal DP. STR improved TTE following prolonged DP (20 ± 16%, P < .001) and revealed a moderate effect size compared to CON (ES = 0.80; P = .07). Furthermore, STR improved TTEdiff more than CON (P = .049). In conclusion, STR superiorly improved 1RM strength, DP performance following prolonged submaximal DP and TTEdiff , indicating a specific effect of improved strength on the ability to maintain performance after long-lasting exercise.

• Hamarsland, Håvard; Nordengen, Anne Lene; Aas, Sigve Nyvik; Holte, Kristin Tosterud; Garthe, Ina & Paulsen, Gøran [Vis alle 10 forfattere av denne artikkelen] (2017). Native whey protein with high levels of leucine results in similar post-exercise muscular anabolic responses as regular whey protein: a randomized controlled trial. Journal of the International Society of Sports Nutrition (JISSN). ISSN 1550-2783. 14:43, s. 1–12. doi: 10.1186/s12970-017-0202-y. Vis sammendrag

  Background: Protein intake is essential to maximally stimulate muscle protein synthesis, and the amino acid leucine seems to possess a superior effect on muscle protein synthesis compared to other amino acids. Native whey has higher leucine content and thus a potentially greater anabolic effect on muscle than regular whey (WPC-80). This study compared the acute anabolic effects of ingesting 2 × 20 g of native whey protein, WPC-80 or milk protein after a resistance exercise session. Methods: A total of 24 young resistance trained men and women took part in this double blind, randomized, partial crossover, controlled study. Participants received either WPC-80 and native whey (n = 10), in a crossover design, or milk (n = 12). Supplements were ingested immediately (20 g) and two hours after (20 g) a bout of heavy-load lower body resistance exercise. Blood samples and muscle biopsies were collected to measure plasma concentrations of amino acids by gas-chromatography mass spectrometry, muscle phosphorylation of p70S6K, 4E–BP1 and eEF-2 by immunoblotting, and mixed muscle protein synthesis by use of [2H5]phenylalanine-infusion, gas-chromatography mass spectrometry and isotope-ratio mass spectrometry. Being the main comparison, differences between native whey and WPC-80 were analysed by a one-way ANOVA and comparisons between the whey supplements and milk were analysed by a two-way ANOVA. Results: Native whey increased blood leucine concentrations more than WPC-80 and milk (P < 0.05). Native whey ingestion induced a greater phosphorylation of p70S6K than milk 180 min after exercise (P = 0.03). Muscle protein synthesis rates increased 1–3 h hours after exercise with WPC-80 (0.119%), and 1–5 h after exercise with native whey (0.112%). Muscle protein synthesis rates were higher 1–5 h after exercise with native whey than with milk (0.112% vs. 0.064, P = 0.023). Conclusions: Despite higher-magnitude increases in blood leucine concentrations with native whey, it was not superior to WPC-80 concerning effect on muscle protein synthesis and phosphorylation of p70S6K during a 5-h post-exercise period. Native whey increased phosphorylation of p70S6K and muscle protein synthesis rates to a greater extent than milk during the 5-h post exercise period.

• Hamarsland, Håvard; Laahne, John Aleksander Larssen; Paulsen, Gøran; Cotter, Matthew; Børsheim, Elisabet & Raastad, Truls (2017). Native whey induces higher and faster leucinemia than other whey protein supplements and milk: a randomized controlled trial. BMC Nutrition. ISSN 2055-0928. 3. doi: 10.1186/s40795-017-0131-9. Vis sammendrag

  Background: Resistance exercise and protein intake are both strong stimuli for muscle protein synthesis. The potential for a protein to acutely increase muscle protein synthesis seems partly dependent on absorption kinetics and the amino acid composition. The aim of this double-blinded randomized cross-over study was to compare time dependent changes in blood amino acid concentrations after ingesting 20 g of five distinct high quality dairy protein supplements (native whey, whey protein concentrate 80, hydrolysed whey, microparticulated whey, and milk proteins). Furthermore, we investigated whether differences in time dependent changes in blood amino acid concentrations affected acute blood glucose and urea responses, and recovery of muscle function after a bout of strength training. Methods: Ten young healthy, recreationally active men ingested different milk protein supplements after a whole-body strength training session on five occasions in a randomized manner. Blood concentrations of amino acids, glucose and urea was measured before and 0, 30, 45, 60, 90, 120 min, and 22 and 30 h post-exercise. Maximal voluntary isometric knee extension and counter movement jump were assessed before, immediately after, 6, 22 and 30 h after exercise. Results: Intake of native whey induced a faster and higher leucinemia than the other protein supplements (p < 0.001). All whey protein supplements showed faster time dependent changes in blood amino acid concentrations for total essential and branched chain amino acids compared to milk. There were no major differences between trials in blood concentrations of glucose or urea, or recovery of muscle function after exercise. Conclusion: Native whey induced the strongest leucinemia and appears to have a greater potential for stimulating muscle protein synthesis than other whey supplements and milk. There were no meaningful differences in blood glucose, urea or recovery of muscle function after the supplements. Future studies should investigate whether the increased leucinemia with native whey translates into greater muscle protein synthesis and muscle mass accretion over time. (NCT02882386, August 16, 2016).

• Rustaden, Anne Mette; Gjestvang, Christina; Bø, Kari; Haakstad, Lene Annette Hagen & Paulsen, Gøran (2017). BodyPump versus traditional heavy load resistance training on changes in resting metabolic rate in overweight untrained women. Journal of Sports Medicine and Physical Fitness. ISSN 0022-4707. 58(9), s. 1304–1311. doi: 10.23736/S0022-4707.17.07613-7. Vis sammendrag

  BACKGROUND: Moderate to heavy load resistance training (RT) is advocated for overweight and obese individuals. One of the beneficial effects of RT is increased resting metabolic rate (RMR), which typically makes up the majority of the total daily energy expenditure. It is, however, unclear if low to moderate load RT affects RMR. Hence, the present study aimed to examine the effects of twelve weeks of BodyPump, on RMR in previous untrained women with BMI ≥25.0, and to compare the results with individual heavy load RT. METHODS: Eighteen overweight women participated in the study (mean age 35.4 years ±10.2, BMI 30.4 kg/m2 ±4.8), ten allocated to BodyPump (high-repetition, low to moderate load RT) and eight to heavy load RT (linear periodization with 3-6, 8-10 and 13-15 repetitions, 2-4 series) Both groups exercised 3 times/week for 12 weeks. RMR was assessed with indirect calorimetry at baseline, midway (after six weeks) and at post-test. RESULTS: Adherence to exercise were 62% and 93% in the BodyPump and heavy load RT group, respectively (p=0.003). RMR in the BodyPump increased with 8.5% (±10.8) from baseline to post-test (p=0.041). The heavy load RT group increased 10.5% (±10.4) from baseline to post-test (p=0.025). There was no significant group difference in RMR from baseline to post-test (p=0.593). CONCLUSIONS: BodyPump and heavy load RT resulted in a similar increase in RMR after 12 weeks of training. Assuming that elevation of RMR is important for combating overweight and obesity, BodyPump appears to have the same potential as heavy load RT.

• Haraldstad, Kristin; Rohde, Gudrun E.; Stea, Tonje Holte; Lohne-Seiler, Hilde; Hetlelid, Ken Joar & Paulsen, Gøran [Vis alle 7 forfattere av denne artikkelen] (2017). Changes in health-related quality of life in elderly men after 12 weeks of strength training. European Review of Aging and Physical Activity. ISSN 1813-7253. 14(1). doi: 10.1186/s11556-017-0177-3. Fulltekst i vitenarkiv Vis sammendrag

  Background: Muscular strength is associated with functional ability in elderly, and older adults are recommended to perform muscle-strengthening exercise. Understanding how improved muscle strength and -mass influence general and specific domains of quality of life is important when planning health promotion efforts targeting older adults. The aims of the present study were to describe changes in health-related quality of life (HRQOL) in older men participating in 12 weeks of systematic strength training, and to investigate whether improvements in muscle strength and muscle mass are associated with enhancements in HRQOL. Methods: We recruited 49 men aged 60–81 years to participate in an intervention study with pre-post assessment. The participants completed a 12-week strength training program consisting of three sessions per week. Tests and measurements aimed at assessing change in HRQOL, and changes in physical performance (maximal strength) and physiological characteristics. HRQOL was measured using the 12-item short-form survey (SF-12). Muscle mass was assessed based on changes in lean mass (leg, trunk, arm, and total), and strength was measured as one-repetition maximum in leg extension, leg press, and biceps curl. Results: Two of the eight HRQOL SF-12 scores, role physical and general health, and the physical component summary scores, increased significantly during the intervention period. Small significant positive correlations were identified between improvements in muscle strength, and better physical and social function. Moreover, a significant increase in total muscle mass was seen during the intervention period. Conclusions: The positive, findings from this study would suggest that systematic strength training seems to be a beneficial intervention to improve HRQOL, muscle strength and muscle mass in older men.

• Stunes, Astrid Kamilla; Syversen, Unni; Berntsen, Sveinung; Paulsen, Gøran; Stea, Tonje Holte & Hetlelid, Ken Joar [Vis alle 11 forfattere av denne artikkelen] (2017). High doses of vitamin C plus E reduce strength training-induced improvements in areal bone mineral density in elderly men. European Journal of Applied Physiology. ISSN 1439-6319. 117(6), s. 1073–1084. doi: 10.1007/s00421-017-3588-y. Vis sammendrag

  Purpose: Resistance training is beneficial for maintaining bone mass. We aimed to investigate the skeletal effects of high doses of antioxidants [vitamin C + E (α-tocopherol)] supplementation during 12-week supervised strength training in healthy, elderly men Methods: Design: double-blinded randomized placebo-controlled study. Participants followed a supervised, undulating periodic exercise program with weekly adjusted load: 3 sessions/week and 3–15 repetitions maximum (RM) sets/exercise. The control group (CG, n = 17, 67 ± 5 years) received placebo and the antioxidant group (AO, n = 16, 70 ± 7 years) 1000 mg vitamin C + 235 mg vitamin E, daily. Areal bone mineral density (aBMD) at whole body, lumbar spine (L1–L4), total hip, and femoral neck were measured by dual energy X-ray absorptiometry and muscle strength by 1RM. Serum analyses of bone-related factors and adipokines were performed. Results: In the CG, total hip aBMD increased by 1.0% (CI: 0.3–1.7) versus pretest and lumbar spine aBMD increased by 0.9% (CI: −0.2 to 2.0) compared to the AO. In the CG, there was an increase in serum concentrations of insulin-like growth factor 1 [+27.3% (CI: −0.3 to 54.9)] and leptin [+31.2% (CI: 9.8–52.6)) versus pretest, and a decrease in sclerostin [−9.9% (CI: 4.4–15.3)] versus pretest and versus AO. Serum bone formation markers P1NP and osteocalcin increased in both groups, while the bone resorption marker CTX-1 remained unchanged. Conclusion: High doses of antioxidant supplementations may constrain the favorable skeletal benefits of 12 weeks of resistance exercise in healthy elderly men.

• Rustaden, Anne Mette; Haakstad, Lene Annette Hagen; Paulsen, Gøran & Bø, Kari (2017). Effects of BodyPump and resistance training with and without a personal trainer on muscle strength and body composition in overweight and obese women-A randomised controlled trial. Obesity Research and Clinical Practice. ISSN 1871-403X. 11(6), s. 728–739. doi: 10.1016/j.orcp.2017.03.003. Vis sammendrag

  Objectives: Overweight and obese individuals are recommended to perform regular resistance training, and the health- and fitness industry offer several exercise programs with purpose to improve muscle strength and body composition. This randomised controlled trial aimed to compare 12 weeks (45–60 min, 3 sessions/weeks) of popular exercise programs, available at health- and fitness centers worldwide. Methods: Previous untrained women with BMI ≥ 25 were allocated to either BodyPump (a high-repetition group session) (n = 25), individual resistance training with a personal trainer (n = 25), non-supervised individual resistance training (n = 21) and non-exercising control group (n = 21). Primary outcome was one repetition maximum (1RM) in squat and bench press, and secondary outcome was body composition (Inbody720). Results: The BodyPump group did not improve muscle strength, compared to any of the other groups. In 1RM squat, the personal trainer group increased 17% (95% CI 5.1–23.0), 20% (95% CI 7.5–24.8) and 30% (95% CI 15.8–33.0 kg) more than the non-supervised group, BodyPump and controls, respectively. In bench press the personal trainer group increased 10% (95% CI 1.5–7.2) and 16% (95% CI 3.5–9.3 kg) more compared to BodyPump and controls. No difference was found compared to the non-supervised group in bench press. There were no between-group differences in body composition. Conclusion: Twelve weeks of BodyPump did not improve muscle strength in overweight women, but a personal trainer amplified the effects of individual resistance training on maximal strength in squat. None of the intervention groups showed effect in body composition.

• Helland, Christian; Hole, Eirik; Olsson, Monica Charlotte; Seynnes, Olivier R.; Solberg, Paul Andre & Paulsen, Gøran (2016). Training Strategies to Improve Muscle Power: Is Olympic-style Weightlifting Relevant? Medicine & Science in Sports & Exercise. ISSN 0195-9131. 49(4), s. 736–745. doi: 10.1249/MSS.0000000000001145. Fulltekst i vitenarkiv Vis sammendrag

  Introduction: This efficacy study investigated the effects of (1) Olympic-style weightlifting (OWL), (2) motorized strength and power training (MSPT), and (3) free weight strength and power training (FSPT) on muscle power. Methods: Thirty-nine young athletes (20±3 yr.; ice hockey, volleyball and badminton) were randomized into the three training groups. All groups participated in 2-3 sessions/week for 8 weeks. The MSPT and FSPT groups trained using squats (two legs and single leg) with high force and high power, while the OWL group trained using clean and snatch exercises. MSPT was conducted as slow-speed isokinetic strength training and isotonic power training with augmented eccentric load, controlled by a computerized robotic engine system. FSPT used free weights. The training volume (sum of repetitions x kg) was similar between all three groups. Vertical jumping capabilities were assessed by countermovement jump (CMJ), squat jump (SJ), drop jump (DJ), and loaded CMJs (10-80 kg). Sprinting capacity was assessed in a 30 m sprint. Secondary variables were squat 1-repetitionmaximum, body composition and quadriceps thickness and architecture. Results: OWL resulted in trivial improvements, and inferior gains compared to FSPT and MSPT for CMJ, SJ, and DJ. MSPT demonstrated small, but robust effects on SJ, DJ and loaded CMJs (3-12%). MSPT was superior to FSPT in improving 30 m sprint performance. FSPT and MSPT, but not OWL, demonstrated increased thickness in the vastus lateralis and rectus femoris (4-7%). Conclusion: MSPT was time-efficient and equally or more effective than FSPT training in improving vertical jumping and sprinting performance. OWL was generally ineffective and inferior to the two other interventions.

• Vella, Luke; Markworth, James F.; Paulsen, Gøran; Raastad, Truls; Peake, Jonathan M. & Snow, Rod J. [Vis alle 8 forfattere av denne artikkelen] (2016). Ibuprofen Ingestion Does Not Affect Markers of Post-exercise Muscle Inflammation. Frontiers in Physiology. ISSN 1664-042X. 7. doi: 10.3389/fphys.2016.00086. Vis sammendrag

  Purpose: We investigated if oral ingestion of ibuprofen influenced leucocyte recruitment and infiltration following an acute bout of traditional resistance exercise. Methods: Sixteen male subjects were divided into two groups that received the maximum over-the-counter dose of ibuprofen (1200 mg d−1 ) or a similarly administered placebo following lower body resistance exercise. Muscle biopsies were taken from m.vastus lateralis and blood serum samples were obtained before and immediately after exercise, and at 3 and 24 h after exercise. Muscle cross-sections were stained with antibodies against neutrophils (CD66b and MPO) and macrophages (CD68). Muscle damage was assessed via creatine kinase and myoglobin in blood serum samples, and muscle soreness was rated on a ten-point pain scale. Results: The resistance exercise protocol stimulated a significant increase in the number of CD66b+ and MPO+ cells when measured 3 h post exercise. Serum creatine kinase, myoglobin and subjective muscle soreness all increased post-exercise. Muscle leucocyte infiltration, creatine kinase, myoglobin and subjective muscle soreness were unaffected by ibuprofen treatment when compared to placebo. There was also no association between increases in inflammatory leucocytes and any other marker of cellular muscle damage. Conclusion: Ibuprofen administration had no effect on the accumulation of neutrophils, markers of muscle damage or muscle soreness during the first 24 h of post-exercise muscle recovery.

• Sagoe, Dominic; Holden, Geir; Rise, Eirin Nygaard Karlsholm; Torgersen, Therese; Paulsen, Gøran & Krosshaug, Tron [Vis alle 8 forfattere av denne artikkelen] (2016). Doping prevention through anti-doping education and practical strength training: The Hercules program. Performance Enhancement & Health. ISSN 2211-2669. 5(1), s. 24–30. doi: 10.1016/j.peh.2016.01.001. Vis sammendrag

  There is a paucity of well-controlled anti-doping interventions. We developed and evaluated the efficacy of a doping prevention program for adolescents – the Hercules program. The program is different from most anti-doping interventions in the combination of theoretical lessons with practical strength training and inclusion of three groups of participants. A total of 202 high school students (females = 98) aged 15–21 years (mean = 16.9) were randomised to the three groups: control (n = 50), theory only (n = 88), and theory with workout (n = 64). Participants completed baseline and posttest questionnaires including demographic, doping use, and psychophysical items/measures. Data were analysed using chi-square tests and mixed between-within analysis of variance. From baseline to posttest, the theory with workout group gained a higher knowledge of anabolic–androgenic steroids (AAS) and their harmful effects as well as a higher increase in strength training self-efficacy. The Hercules program seems valuable in providing adolescents knowledge on AAS and their harmful effects as well as positive strength training skills. The program elucidates the benefits of combining anti-doping education with practical strength training in doping prevention.

• Angeltveit, Andreas; Paulsen, Gøran; Solberg, Paul Andre & Raastad, Truls (2016). Validity, Reliability, and Performance Determinants of a New Job-Specific Anaerobic Work Capacity Test for the Norwegian Navy Special Operations Command. Journal of Strength and Conditioning Research. ISSN 1064-8011. 30(2), s. 487–496. doi: 10.1519/JSC.0000000000001041. Vis sammendrag

  Operators in Special Operation Forces (SOF) have a particularly demanding profession where physical and psychological capacities can be challenged to the extremes. The diversity of physical capacities needed depend on the mission. Consequently, tests used to monitor SOF operators' physical fitness should cover a broad range of physical capacities. Whereas tests for strength and aerobic endurance are established, there is no test for specific anaerobic work capacity described in the literature. The purpose of this study was therefore to evaluate the reliability, validity, and to identify performance determinants of a new test developed for testing specific anaerobic work capacity in SOF operators. Nineteen active young students were included in the concurrent validity part of the study. The students performed the evacuation (EVAC) test 3 times and the results were compared for reliability and with performance in the Wingate cycle test, 300-m sprint, and a maximal accumulated oxygen deficit (MAOD) test. In part II of the study, 21 Norwegian Navy Special Operations Command operators conducted the EVAC test, anthropometric measurements, a dual x-ray absorptiometry scan, leg press, isokinetic knee extensions, maximal oxygen uptake test, and countermovement jump (CMJ) test. The EVAC test showed good reliability after 1 familiarization trial (intraclass correlation = 0.89; coefficient of variance = 3.7%). The EVAC test correlated well with the Wingate test (r = -0.68), 300-m sprint time (r = 0.51), and 300-m mean power (W) (r = -0.67). No significant correlation was found with the MAOD test. In part II of the study, height, body mass, lean body mass, isokinetic knee extension torque, maximal oxygen uptake, and maximal power in a CMJ was significantly correlated with performance in the EVAC test. The EVAC test is a reliable and valid test for anaerobic work capacity for SOF operators, and muscle mass, leg strength, and leg power seem to be the most important determinants of performance.

• Stea, Tonje Holte; Berntsen, Solvor; Berntsen, Sveinung; Bastani, Nasser Ezzatkhah; Paulsen, Gøran & Seiler, Hilde Lohne [Vis alle 9 forfattere av denne artikkelen] (2016). Effect of Omega-3 and Vitamins e + C Supplements on the Concentration of Serum B-Vitamins and Plasma Redox Aminothiol Antioxidant Status in Elderly Men after Strength Training for Three Months. Annals of Nutrition and Metabolism. ISSN 0250-6807. 68(2), s. 145–155. doi: 10.1159/000443847.
• Moltubakk, Marie M.; Eriksrud, Ola; Paulsen, Gøran; Seynnes, Olivier R. & Bojsen-Møller, Jens (2016). Hamstrings functional properties in athletes with high musculo-skeletal flexibility. Scandinavian Journal of Medicine & Science in Sports. ISSN 0905-7188. 26(6), s. 659–665. doi: 10.1111/sms.12488. Vis sammendrag

  The purpose of this study was to examine whether athletes with highly flexible hamstring muscle-tendon units display different passive and contractile mechanical properties compared with controls. Flexibility, passive, and active torque–angle properties were assessed in 21 female elite rhythmic gymnasts and 16 female age-matched athletes. Passive resistance to stretch was measured during knee extension with the hip fixed at 100° of flexion. Concentric isokinetic maximal voluntary knee flexion and extension torques were measured at 60°/s in the same position. Tests of flexibility and passive resistance to stretch indicated a greater flexibility in the gymnasts. Despite no differences between groups in knee flexion and extension peak torque, gymnasts reached knee flexion peak torque at more extended positions (longer muscle lengths) and displayed significantly different torque–angle relations. When active torque was corrected for passive resistance to stretch, differences increased, gymnasts producing more work, and maintaining ≥ 70% of peak torque over a larger range of joint excursion. In conclusion, individuals with a higher flexibility of the hamstrings MTU present a different torque–angle profile, favoring the production of flexion torque toward extended knee positions, displaying larger functional range of motion and a higher mechanical work output during knee flexion.

• Schmidt, Harald; Stocker, Roland; Vollbracht, Claudia; Paulsen, Gøran; Riley, Dennis & Daiber, Andreas [Vis alle 7 forfattere av denne artikkelen] (2015). Antioxidants in Translational Medicine. Antioxidants and Redox Signaling. ISSN 1523-0864. 23(14), s. 1130–1143. doi: 10.1089/ars.2015.6393. Vis sammendrag

  Significance: It is generally accepted that reactive oxygen species (ROS) scavenging molecules or antioxidants exert health-promoting effects and thus their consumption as food additives and nutraceuticals has been greatly encouraged. Antioxidants may be beneficial in situations of subclinica l deficiency and increased demand or acutely upon high-dose infusion. However, to date, there is little clinical evidence for the long-term benefit of most antioxidants. Alarmingly, recent evidence points even to health risks, in pa rticular for supplements of lipophilic antioxidants. Recent Advances: The biological impact of ROS depends not only on their quantit ies but also on their chemical nature, (sub)cellular and tissue location, and the rates of their formation and de gradation. Moreover, ROS serve important physiological functions; thus, inappropriate removal of ROS may cause pa radoxical reductive stress and thereby induce or promote disease. Critical Issues: Any recommendation on antioxidants must be based on solid clinical evidence and patient- relevant outcomes rather than surrogate parameters. Future Directions: Such evidence-based use may include site- directed application, time-limited hi gh dosing, (functional) pharmacological repair of oxidized biomolecules, and triggers of endogenous antioxidant response systems. Ideally , these approaches need guidance by patient stratification through predictive biomarkers and possibly imaging modalities.

• Solberg, Paul Andre; Paulsen, Gøran; Slaathaug, Ole Gunnar; Skare, Magnhild; Dallas, Wood & Huls, Shaun [Vis alle 7 forfattere av denne artikkelen] (2015). Development and implementation of a new physical training concept in the norwegian navy special operations command. Journal of Strength and Conditioning Research. ISSN 1064-8011. 29(11s), s. s204–s210. doi: 10.1519/JSC.0000000000001085. Vis sammendrag

  A high level of physical fitness is one important factor for optimal performance in Special Operation Forces (SOF). Still, information about physical training for SOF operators is not easily accessible. This study aimed to implement and assess a new training concept in the Norwegian Navy SOF. A longitudinal study where 22 operators completed a 6-month linear periodization (LP), followed by a 6-month nonlinear periodization (NLP) program. Both protocols were block periodized, focusing on either strength or aerobic capacity. A battery of tests covering strength, endurance, power, mobility, and body composition was performed, and individual capacity analyses were established. A training week consisted of 5 to 6 sessions including 1 or 2 individualized sessions directed towards improving the weakest capacity. The LP had a clear effect on mobility (19 ± 9%), abdominal strength (25 ± 16%), upper body power (PowerUB; 6 ± 9%), standing long-jump (3 ± 6%), pull-ups (24 ± 31%), agility (2 ± 4%), V[Combining Dot Above]O2max (2 ± 3%), fat percent (-5 ± 31%), and muscle mass (1 ± 3%). The NLP increased abdominal strength (15 ± 17%), standing long-jump (3 ± 4%), and anaerobic capacity (10 ± 8%), whereas V[Combining Dot Above]O2 max (-3 ± 4%) and PowerUB (-2 ± 7%) decreased. Additional analyses showed clear increases among those individually instructed to improve strength. Results support the benefits of combined periodized programming and individualized training sessions among SOF operators with initially good fitness levels. Largest effects were observed in the first phase with the LP. However, subsequent NLP additionally increased anaerobic and jumping capacity, possibly due to more frequent muscular endurance and power training. Because of frequent interruptions, the LP tended to be more difficult to follow than the NLP and is suggested when continuity is possible, whereas an NLP is recommended for maintenance and when standing on national preparedness.

• Bjørnsen, Thomas; Salvesen, Svein; Berntsen, Sveinung; Hetlelid, Ken Joar; Stea, Tonje Holte & Seiler, Hilde Lohne [Vis alle 17 forfattere av denne artikkelen] (2015). Vitamin C and E supplementation blunts increases in total lean body mass in elderly men after strength training. Scandinavian Journal of Medicine & Science in Sports. ISSN 0905-7188. 26(7). doi: 10.1111/sms.12506. Vis sammendrag

  The aim of this study was to investigate the effects of vitamin C and E supplementation on changes in muscle mass (lean mass and muscle thickness) and strength during 12 weeks of strength training in elderly men. Thirty-four elderly males (60–81 years) were randomized to either an antioxidant group (500 mg of vitamin C and 117.5 mg vitamin E before and after training) or a placebo group following the same strength training program (three sessions per week). Body composition was assessed with dual-energy X-ray absorptiometry and muscle thickness by ultrasound imaging. Muscle strength was measured as one-repetition maximum (1RM). Total lean mass increased by 3.9% (95% confidence intervals: 3.0, 5.2) and 1.4% (0, 5.4) in the placebo and antioxidant groups, respectively, revealing larger gains in the placebo group (P = 0.04). Similarly, the thickness of m. rectus femoris increased more in the placebo group [16.2% (12.8, 24.1)] than in the antioxidant group [10.9% (9.8, 13.5); P = 0.01]. Increases of lean mass in trunk and arms, and muscle thickness of elbow flexors, did not differ significantly between groups. With no group differences, 1RM improved in the range of 15–21% (P < 0.001). In conclusion, high-dosage vitamin C and E supplementation blunted certain muscular adaptations to strength training in elderly men.

• Isanejad, Amin; Saraf, Zahir Hassan; Mahdavi, Mehdi; Gharakhanlou, Reza; Shamsi, Mahdieh Molanouri & Paulsen, Gøran (2015). The effect of endurance training and downhill running on the expression of IL-1β, IL-6, and TNF-α and HSP72 in rat skeletal muscle. Cytokine. ISSN 1043-4666. 73(2), s. 302–308. doi: 10.1016/j.cyto.2015.03.013. Vis sammendrag

  This study investigated changes in the myokines IL-1β, IL-6, and TNF-α, as well as HSP72, after endurance training and after a session of downhill running. Twenty-eight rats were allocated to four different groups: 1. Eight weeks of endurance training at 65–70% VO2max (Trained); 2. Endurance training and a single session of downhill running on a 16° slope (Trained plus downhill); 3. A single session of downhill running (Sedentary plus downhill); and 4. Sedentary (Control, no exercise). Soleus and extensor digitorum longus (EDL) muscles were harvested 48 h after training and/or a single session of downhill running and protein levels of IL-1β, IL-6, TNF-α, and HSP72 were measured and compared to the levels in the control animals. Creatine kinase (CK) was measured in plasma. Endurance training augmented intramuscular levels of HSP72 and IL-6 in both soleus and EDL muscles (p < 0.05). Endurance training elevated IL-1β and decreased TNF-α significantly only in EDL (P < 0.05). IL-6 increased in both sedentary and trained rats after downhill running (P < 0.05), while HSP72 increased only in the previously sedentary rats. CK was lower in trained than sedentary rats after downhill running. In conclusion, endurance training for 8 weeks elevated muscular HSP72 protein levels, which might have preconditioned the muscles for a single session of downhill running, as indicated by the CK and HSP72 responses. Interestingly, IL-6 was augmented by endurance training and further increased by downhill running. IL-1β, along with IL-6, was increased by endurance training, and these myokines thus appear to be differently regulated than TNF-α.

• Haugen, Thomas Andre; Tønnessen, Espen; Øksenholt, Øyvind Øvrebø; Haugen, Fredrik Lie; Paulsen, Gøran & Enoksen, Eystein [Vis alle 7 forfattere av denne artikkelen] (2015). Sprint Conditioning of Junior Soccer Players: Effects of Training Intensity and Technique Supervision. PLOS ONE. ISSN 1932-6203. 10(3). doi: 10.1371/journal.pone.0121827. Fulltekst i vitenarkiv Vis sammendrag

  The aims of the present study were to compare the effects of 1) training at 90 and 100% sprint velocity and 2) supervised versus unsupervised sprint training on soccer-specific physical performance in junior soccer players. Young, male soccer players (17 ±1 yr, 71 ±10 kg, 180 ±6 cm) were randomly assigned to four different treatment conditions over a 7-week intervention period. A control group (CON, n=9) completed regular soccer training according to their teams’ original training plans. Three training groups performed a weekly repeated-sprint training session in addition to their regular soccer training sessions performed at A) 100% intensity without supervision (100UNSUP, n=13), B) 90% of maximal sprint velocity with supervision (90SUP, n=10) or C) 90% of maximal sprint velocity without supervision (90UNSUP, n=13). Repetitions x distance for the sprint-training sessions were 15x20 m for 100UNSUP and 30x20 m for 90SUP and 90UNSUP. Single-sprint performance (best time from 15x20 m sprints), repeated-sprint performance (mean time over 15x20 m sprints), countermovement jump and Yo-Yo Intermittent Recovery Level 1 (Yo-Yo IR1) were assessed during pre-training and post-training tests. No significant differences in performance outcomes were observed across groups. 90SUP improved Yo-Yo IR1 by a moderate margin compared to controls, while all other effect magnitudes were trivial or small. In conclusion, neither weekly sprint training at 90 or 100% velocity, nor supervised sprint training enhanced soccer-specific physical performance in junior soccer players.

• Paulsen, Gøran; Hamarsland, Håvard; Cumming, Kristoffer Toldnes; Johansen, Rasmus Einar; Hulmi, Juha J. & Børsheim, Elisabet [Vis alle 9 forfattere av denne artikkelen] (2014). Vitamin C and E supplementation alters protein signalling after a strength training session, but not muscle growth during 10 weeks of training. Journal of Physiology. ISSN 0022-3751. 592(24), s. 5391–5408. doi: 10.1113/jphysiol.2014.279950. Vis sammendrag

  This study investigated the effects of vitamin C and E supplementation on acute responses and adaptations to strength training. Thirty-two recreationally strength-trained men and women were randomly allocated to receive a vitamin C and E supplement (1000 mg day−1 and 235 mg day−1, respectively), or a placebo, for 10 weeks. During this period the participants’ training involved heavy-load resistance exercise four times per week. Muscle biopsies from m. vastus lateralis were collected, and 1 repetition maximum (1RM) and maximal isometric voluntary contraction force, body composition (dual-energy X-ray absorptiometry), and muscle cross-sectional area (magnetic resonance imaging) were measured before and after the intervention. Furthermore, the cellular responses to a single exercise session were assessed midway in the training period by measurements of muscle protein fractional synthetic rate and phosphorylation of several hypertrophic signalling proteins. Muscle biopsies were obtained from m. vastus lateralis twice before, and 100 and 150 min after, the exercise session (4 × 8RM, leg press and knee-extension). The supplementation did not affect the increase in muscle mass or the acute change in protein synthesis, but it hampered certain strength increases (biceps curl). Moreover, increased phosphorylation of p38 mitogen-activated protein kinase, Extracellular signal-regulated protein kinases 1 and 2 and p70S6 kinase after the exercise session was blunted by vitamin C and E supplementation. The total ubiquitination levels after the exercise session, however, were lower with vitamin C and E than placebo. We concluded that vitamin C and E supplementation interfered with the acute cellular response to heavy-load resistance exercise and demonstrated tentative long-term negative effects on adaptation to strength training.

• Paulsen, Gøran; Cumming, Kristoffer Toldnes; Hamarsland, Håvard; Børsheim, Elisabeth; Berntsen, Sveinung & Raastad, Truls (2014). Can supplementation with vitamin C and E alter physiological adaptations to strength training? BMC sports science, medicine and rehabilitation. ISSN 2052-1847. 6(1). doi: 10.1186/2052-1847-6-28. Vis sammendrag

  Background: Antioxidant supplementation has recently been demonstrated to be a double-edged sword, because small to moderate doses of exogenous antioxidants are essential or beneficial, while high doses may have adverse effects. The adverse effects can be manifested in attenuated effects of exercise and training, as the antioxidants may shut down some redox-sensitive signaling in the exercised muscle fibers. However, conditions such as age may potentially modulate the need for antioxidant intake. Therefore, this paper describes experiments for testing the hypothesis that high dosages of vitamin C (1000 mg/day) and E (235 mg/day) have negative effects on adaptation to resistance exercise and training in young volunteers, but positive effects in older men. Methods/design: We recruited a total of 73 volunteers. The participants were randomly assigned to receiving either vitamin C and E supplementation or a placebo. The study design was double-blinded, and the participants followed an intensive training program for 10 – 12 weeks. Tests and measurements aimed at assessing changes in physical performance (maximal strength) and physiological characteristics (muscle mass), as well as biochemical and cellular systems and structures (e.g., cell signaling and morphology). Discussion: Dietary supplements, such as vitamin C and E, are used by many people, especially athletes. The users often believe that high dosages of supplements improve health (resistance to illness and disease) and physical performance. These assumptions are, however, generally not supported in the scientific literature. On the contrary, some studies have indicated that high dosages of antioxidant supplements have negative effects on exercise-induced adaptation processes. Since this issue concerns many people and few randomized controlled trials have been conducted in humans, further studies are highly warranted.

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• Andersen, Vidar; Hermans, Espen ; Vereide, Vegard Albert; Stien, Nicolay; Paulsen, Gøran & Baláš, Jiří [Vis alle 9 forfattere av denne artikkelen] (2023). Publisher Correction: Comparison of finger flexor resistance training, with and without blood flow restriction, on perceptional and physiological responses in advanced climbers (Scientific Reports, (2023), 13, 1, (3287), 10.1038/s41598-023-30499-x). Scientific Reports. ISSN 2045-2322. 13(1). doi: 10.1038/s41598-023-31266-8.
• Lindberg, Kolbjørn Andreas; Bjørnsen, Thomas; Vårvik, Fredrik Tonstad; Paulsen, Gøran; joensen, malene & Kristoffersen, Morten [Vis alle 11 forfattere av denne artikkelen] (2022). When You Believe You Are In The Intervention Group, You Will Get Better Training Results. A Randomized Controlled Placebo Study .
• Bjørnsen, Thomas; Hody, Stephanie; Raastad, Truls; Paulsen, Gøran; Wernbom, Mathias & Vårvik, Fredrik Tonstad [Vis alle 8 forfattere av denne artikkelen] (2022). High-Frequency Blood Flow Restricted Resistance Exercise To Failure Induces Higher Cellular Stress In Muscle Fibres Than A Non-Failure Protocol .
• Wernbom, Mathias; Paulsen, Gøran; Bjørnsen, Thomas; Cumming, Kristoffer Toldnes & Raastad, Truls (2021). Reply - Letter to the editor. Clinical Journal of Sports Medicine. ISSN 1050-642X. 31(6), s. e513–e513. doi: 10.1097/JSM.0000000000000854.
• Stenqvist, Thomas Birkedal; Melin, Anna Katarina; Garthe, Ina; Slater, Gary; Paulsen, Gøran & Torstveit, Monica Klungland (2020). RELATIVE ENERGY DEFICIENCY IN SPORT AMONG MALE NORWEGIAN WORLD-CLASS ATHLETES.
• Bjørnsen, Thomas; Lindberg, Kolbjørn; Solberg, Paul Andre; Rønnestad, Bent; Frank, Martin & Abusdal, Gøran [Vis alle 9 forfattere av denne artikkelen] (2020). THE EFFECT OF INDIVIDUALIZED POWER-TRAINING BASED ON FORCE-VELOCITY PROFILING IN HIGHLY-TRAINED TEAM SPORT ATHLETES.
• Lindberg, Kolbjørn; Solberg, Paul Andre; Bjørnsen, Thomas; Helland, Christian; Rønnestad, Bent & Frank, Martin [Vis alle 10 forfattere av denne artikkelen] (2020). FORCE-VELOCITY PROFILING IN ELITE ATHLETES: RELIABILITY AND AGREEMENT BETWEEN METHODS.
• Wernbom, Mathias; Schoenfeld, Brad J; Paulsen, Gøran; Bjørnsen, Thomas; Cumming, Kristoffer Toldnes & Aagaard, Per [Vis alle 8 forfattere av denne artikkelen] (2020). Commentary: Can Blood Flow Restricted Exercise Cause Muscle Damage? Commentary on Blood Flow Restriction Exercise: Considerations of Methodology, Application, and Safety. Frontiers in Physiology. ISSN 1664-042X. 11. doi: 10.3389/fphys.2020.00243.
• Helland, Christian; Haugen, Tommy; Rakovic, Elvir; Eriksrud, Ola; Seynnes, Olivier R. & Mero, Antti A. [Vis alle 7 forfattere av denne artikkelen] (2019). Correction to: Force–velocity profiling of sprinting athletes: single-run vs. multiple-run methods (European Journal of Applied Physiology, (2019), 119, 2, (465-473), 10.1007/s00421-018-4045-2). European Journal of Applied Physiology. ISSN 1439-6319. 119(2). doi: 10.1007/s00421-018-04057-7.
• Wernbom, Mathias; Seynnes, Olivier R. & Paulsen, Gøran (2019). Commentaries on Viewpoint: Distinct modalities of eccentric exercise: different recipes, not the same dish. Journal of applied physiology. ISSN 8750-7587. 127(3), s. 884–891. doi: 10.1152/japplphysiol.00496.2019.
• Jåbekk, Pål & Paulsen, Gøran (2019). Muskelstyrke, muskelvekst, trening og fysiologi med Gøran Paulsen. [Internett]. https://larsogpaal.libsyn.com/episode-65-muskelstyrke-muskel.
• McGhie, David; Østerås, Sindre; Ettema, Gertjan; Paulsen, Gøran & Sandbakk, Øyvind (2018). Strength determinants of jump height in the jump throw movement in women handball players.
• Bruusgaard, Jo C.; Kalhovde, John Magne; Paulsen, Gøran; Sefland, Iren; Støve, Kjersti & Raastad, Truls (2018). Tetranectin labels myofibrillar disruptions after eccentric exercise in humans. Journal of Muscle Research and Cell Motility. ISSN 0142-4319. doi: 10.1007/s10974-016-9457-1.
• Schmidt, Harald H.H.W.; Stocker, Roland; Paulsen, Gøran; Ghezzi, Pietro; Riley, Dennis & Daiber, Andreas [Vis alle 7 forfattere av denne artikkelen] (2016). Response to I. Batinic-Haberle et al. Antioxidants and Redox Signaling. ISSN 1523-0864. 24(9), s. 525–526. doi: 10.1089/ars.2016.29029.hhs.
• Bruusgaard, Jo C.; Kalhovde, John Magne; Raastad, Truls; Paulsen, Gøran; Støve, Kjersti & Sefland, Iren (2016). Tetranectin labels myofibrillar disruptions after eccentric exercise in humans.
• Andersen, Vidar; Mo, Dag-Andrè & Paulsen, Gøran (2016). Tung styrke - implementering av strikk i den tradisjonelle styrketreningen.
• Krosshaug, Tron; Petushek, Erich; Richter, Christopher; Paulsen, Gøran & Faul, Oliver (2015). Effect of load and various equipment modalities on back squat biomechanics in elite powerlifters.
• Stunes, Astrid Kamilla; Syversen, Unni; Berntsen, Sveinung; Paulsen, Gøran; Stea, Tonje Holte & Hetlelid, Ken Joar [Vis alle 9 forfattere av denne artikkelen] (2015). Vitamin C and E supplementation reduces the beneficial skeletal effects of strength training in elderly men.
• Vegge, Geir; Rønnestad, Bent & Paulsen, Gøran (2014). Acute effects of vibration on muscle activation during high and low loading.

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