Publikasjoner
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Galvan-Alvarez, Victor; Martin-Rincon, Marcos; Gallego-Selles, Angel; Martínez Canton, Miriam; HamedChaman, NaDer & Gelabert-Rebato, Miriam
[Vis alle 13 forfattere av denne artikkelen]
(2023).
Determinants of the maximal functional reserve during repeated supramaximal exercise by humans: The roles of Nrf2/Keap1, antioxidant proteins, muscle phenotype and oxygenation.
Redox Biology.
ISSN 2213-2317.
66.
doi:
10.1016/j.redox.2023.102859.
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When high-intensity exercise is performed until exhaustion a “functional reserve” (FR) or capacity to produce power at the same level or higher than reached at exhaustion exists at task failure, which could be related to reactive oxygen and nitrogen species (RONS)-sensing and counteracting mechanisms. Nonetheless, the magnitude of this FR remains unknown. Repeated bouts of supramaximal exercise at 120% of VO2max interspaced with 20s recovery periods with full ischaemia were used to determine the maximal FR. Then, we determined which muscle phenotypic features could account for the variability in functional reserve in humans. Exercise performance, cardiorespiratory variables, oxygen deficit, and brain and muscle oxygenation (near-infrared spectroscopy) were measured, and resting muscle biopsies were obtained from 43 young healthy adults (30 males). Males and females had similar aerobic (VO2max per kg of lower extremities lean mass (LLM): 166.7 ± 17.1 and 166.1 ± 15.6 ml kg LLM−1.min−1, P = 0.84) and anaerobic fitness (similar performance in the Wingate test and maximal accumulated oxygen deficit when normalized to LLM). The maximal FR was similar in males and females when normalized to LLM (1.84 ± 0.50 and 2.05 ± 0.59 kJ kg LLM−1, in males and females, respectively, P = 0.218). This FR depends on an obligatory component relying on a reserve in glycolytic capacity and a putative component generated by oxidative phosphorylation. The aerobic component depends on brain oxygenation and phenotypic features of the skeletal muscles implicated in calcium handling (SERCA1 and 2 protein expression), oxygen transport and diffusion (myoglobin) and redox regulation (Keap1). The glycolytic component can be predicted by the protein expression levels of pSer40-Nrf2, the maximal accumulated oxygen deficit and the protein expression levels of SOD1. Thus, an increased capacity to modulate the expression of antioxidant proteins involved in RONS handling and calcium homeostasis may be critical for performance during high-intensity exercise in humans.
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Martinez-Canton, Miriam; Galvan-Alvarez, Victor; Garcia-Gonzalez, Eduardo; Gallego-Selles, Angel; Gelabert-Rebato, Miriam & Garcia-Perez, Giovanni
[Vis alle 11 forfattere av denne artikkelen]
(2023).
A Mango Leaf Extract (Zynamite®) Combined with Quercetin Has Exercise-Mimetic Properties in Human Skeletal Muscle.
Nutrients.
ISSN 2072-6643.
15(13).
doi:
10.3390/nu15132848.
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Zynamite PX®, a mango leaf extract combined with quercetin, enhances exercise performance by unknown molecular mechanisms. Twenty-five volunteers were assigned to a control (17 males) or supplementation group (8 males, receiving 140 mg of Zynamite® + 140 mg quercetin/8 h for 2 days). Then, they performed incremental exercise to exhaustion (IE) followed by occlusion of the circulation in one leg for 60 s. Afterwards, the cuff was released, and a 30 s sprint was performed, followed by 90 s circulatory occlusion (same leg). Vastus lateralis muscle biopsies were obtained at baseline, 20 s after IE (occluded leg) and 10 s after Wingate (occluded leg), and bilaterally at 90 s and 30 min post exercise. Compared to the controls, the Zynamite PX® group showed increased basal protein expression of Thr287-CaMKIIδD (2-fold, p = 0.007) and Ser9-GSK3β (1.3-fold, p = 0.005) and a non-significant increase of total NRF2 (1.7-fold, p = 0.099) and Ser40-NRF2 (1.2-fold, p = 0.061). In the controls, there was upregulation with exercise and recovery of total NRF2, catalase, glutathione reductase, and Thr287-CaMKIIδD (1.2–2.9-fold, all p < 0.05), which was not observed in the Zynamite PX® group. In conclusion, Zynamite PX® elicits muscle signaling changes in resting skeletal muscle resembling those described for exercise training and partly abrogates the stress kinases responses to exercise as observed in trained muscles.
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Martin-Rodriguez, Saúl; Gonzalez-Henriquez, Juan Jose; Galvan-Alvarez, Victor; Cruz-Ramírez, Sara; Calbet, Jose Antonio Lopez & Sanchis-Moysi, Joaquín
(2023).
Architectural anatomy of the human tibialis anterior presents morphological asymmetries between superficial and deep unipennate regions.
Journal of Anatomy.
ISSN 0021-8782.
doi:
10.1111/joa.13864.
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The tibialis anterior muscle plays a critical role in human ambulation and contributes to maintaining the upright posture. However, little is known about its muscle architecture in males and females. One hundred and nine physically active males and females were recruited. Tibialis anterior muscle thickness, pennation angle, and fascicle length were measured at rest in both unipennate regions of both legs using real-time ultrasound imaging. A linear mixed model was used with muscle thickness, pennation angle, or fascicle length as the dependent variables. All models were carried out with and without total leg lean mass and shank length as covariates. Causal mediation analysis was computed to explore the effect of muscle thickness on the relationship between fascicle length and pennation angle. There were no significant differences between dominant and nondominant legs regarding muscle architecture. Muscle thickness and pennation angle were greater in the deep than the superficial unipennate region in males (1.9 mm and 1.1°, p < 0.001) and women (3.4 mm and 2.2°, p < 0.001). However, the fascicle length was similar in both regions for both sexes. The differences remained significant after accounting for differences in leg lean mass and shank length. In both regions, muscle thickness was 1–3 mm greater in males and superficial pennation angle 2° smaller in females (both, p < 0.001). After accounting for leg lean mass and shank length, sex differences remained for muscle thickness (1.6 mm, p < 0.05) and pennation angle (3.4°, p < 0.001) but only in the superficial region. In both regions, leg lean mass and shank-adjusted fascicle length were 1.4 mm longer in females than males (p < 0.05). The causal mediation analysis revealed that the estimation of fascicle length was positive, suggesting that a 10% increase in muscle thickness would augment the fascicle length, allowing a 0.38° pennation angle decrease. Moreover, the pennation angle increases in total by 0.54° due to the suppressive effect of the increase in fascicle length. The estimated mediation, direct, and total effects were all significantly different from zero (p < 0.001). Overall, our results indicate that the architectural anatomy of the tibialis anterior shows sexual dimorphism in humans. Tibialis anterior presents morphological asymmetries between superficial and deep unipennate regions in both sexes. Lastly, our causal mediation model identified a suppressive effect of fascicle length on the pennation angle, suggesting that increments in muscle thickness are not always aligned with increments in fascicle length or the pennation angle.
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González-Alonso, José; Calbet, Jose Antonio Lopez; Mora-Rodríguez, Ricardo & Kippelen, Pascale
(2023).
Pulmonary ventilation and gas exchange during prolonged exercise in humans: Influence of dehydration, hyperthermia and sympathoadrenal activity.
Experimental Physiology.
ISSN 0958-0670.
108(2),
s. 188–206.
doi:
10.1113/EP090909.
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The mechanisms driving hyperthermic hyperventilation during exercise are unclear. In a series of retrospective analyses, we evaluated the impact of combined versus isolated dehydration and hyperthermia and the effects of sympathoadrenal discharge on ventilation and pulmonary gas exchange during prolonged intense exercise. In the first study, endurance-trained males performed two submaximal cycling exercise trials in the heat. On day 1, participants cycled until volitional exhaustion (135 ± 11 min) while experiencing progressive dehydration and hyperthermia. On day 2, participants maintained euhydration and core temperature (Tc) during a time-matched exercise (control). At rest and during the first 20 min of exercise, pulmonary ventilation (
), arterial blood gases, CO2 output and O2 uptake were similar in both trials. At 135 ± 11 min, however,
was elevated with dehydration and hyperthermia, and this was accompanied by lower arterial partial pressure of CO2, higher breathing frequency, arterial partial pressure of O2, arteriovenous CO2 and O2 differences, and elevated CO2 output and unchanged O2 uptake despite a reduced pulmonary circulation. The increased
was closely related to the rise in Tc and circulating catecholamines (R2 ≥ 0.818, P ≤ 0.034). In three additional studies in different participants, hyperthermia independently increased
to an extent similar to combined dehydration and hyperthermia, whereas prevention of hyperthermia in dehydrated individuals restored
to control levels. Furthermore, adrenaline infusion during exercise elevated both Tc and
. These findings indicate that: (1) adjustments in pulmonary gas exchange limit homeostatic disturbances in the face of a blunted pulmonary circulation; (2) hyperthermia is the main stimulus increasing ventilation during prolonged intense exercise; and (3) sympathoadrenal activation might partly mediate the hyperthermic hyperventilation.
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Galván-álvarez, Víctor; Pérez-Suarez, Ismael; Martín-Rincón, Marcos & Calbet, Jose Antonio Lopez
(2022).
Accurate assessment of walking energy expenditure in the main seafront walking route of Las Palmas de Gran Canaria to promote health-related tourism.
Cultura_Ciencia_Deporte (CCD).
ISSN 1696-5043.
17(54),
s. 33–41.
doi:
10.12800/ccd.v17i54.1911.
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Gallego-Selles, Angel; Galvan-Alvarez, Victor; Martinez-Canton, Miriam; Garcia-Gonzalez, Eduardo; Morales-Alamo, David & Santana, Alfredo
[Vis alle 10 forfattere av denne artikkelen]
(2022).
Fast regulation of the NF-κB signalling pathway in human skeletal muscle revealed by high-intensity exercise and ischaemia at exhaustion: Role of oxygenation and metabolite accumulation.
Redox Biology.
ISSN 2213-2317.
55.
doi:
10.1016/j.redox.2022.102398.
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The NF-κB signalling pathway plays a critical role in inflammation, immunity, cell proliferation, apoptosis, and muscle metabolism. NF-κB is activated by extracellular signals and intracellular changes in Ca2+, Pi, H+, metabolites and reactive oxygen and nitrogen species (RONS). However, it remains unknown how NF-κB signalling is activated during exercise and how metabolite accumulation and PO2 influence this process. Eleven active men performed incremental exercise to exhaustion (IE) in normoxia and hypoxia (PIO2:73 mmHg). Immediately after IE, the circulation of one leg was instantaneously occluded (300 mmHg). Muscle biopsies from m. vastus lateralis were taken before (Pre), and 10s (Post, occluded leg) and 60s after exercise from the occluded (Oc1m) and free circulation (FC1m) legs simultaneously together with femoral vein blood samples. NF-κB signalling was activated by exercise to exhaustion, with similar responses in normoxia and acute hypoxia, as reflected by the increase of p105, p50, IKKα, IκBβ and glutathione reductase (GR) protein levels, and the activation of the main kinases implicated, particularly IKKα and CaMKII δD, while IKKβ remained unchanged. Postexercise ischaemia maintained and stimulated further NF-κB signalling by impeding muscle reoxygenation. These changes were quickly reverted at the end of exercise when the muscles recovered with open circulation. Finally, we have shown that Thioredoxin 1 (Trx1) protein expression was reduced immediately after IE and after 1 min of occlusion while the protein expression levels of glutathione peroxidase 1 (Gpx1) and thioredoxin reductase 1 (TrxR1) remained unchanged. These novel data demonstrate that exercising to exhaustion activates NF-κB signalling in human skeletal muscle and regulates the expression levels of antioxidant enzymes in human skeletal muscle. The fast regulation of NF-κB at exercise cessation has implications for the interpretation of published studies and the design of new experiments.
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Rodríguez de Rivera, Pedro Jesús; Rodríguez de Rivera, Miriam; Socorro, Fabiola; Calbet, Jose Antonio Lopez & Rodríguez de Rivera, Manuel
(2022).
Advantages of in vivo measurement of human skin thermal conductance using a calorimetric sensor.
Journal of Thermal Analysis and Calorimetry.
ISSN 1388-6150.
doi:
10.1007/s10973-022-11275-x.
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Thermal conductivity of the skin has been measured by in vivo procedures since the 1950s. These devices usually consist of temperature sensors and heating elements. In vivo measurement of skin thermal conductivity entails several difficulties. It is necessary to adequately characterize the excitation produced by the measurement. In addition, the thermal penetration depth of each instrument is different. These factors have led to the development of a multitude of techniques to measure the thermal conductivity or related magnitudes such as thermal conductance. In our case, we have built a calorimetric sensor designed to measure this magnitude directly and non-invasively. The device implements the basic principles of calorimetry and is capable of characterizing the thermal magnitudes of a 2 × 2 (4) cm2 skin region. The sensor consists of a measuring thermopile with a thermostat cooled by Peltier effect. Several skin measurements performed under different conditions resulted in a thermal conductance ranging from 0.017 to 0.050 WK−1. This magnitude, measured in vivo, is different in each studied area and depends on several factors, such as physical activity and the physiological state of the subject. This new sensor is a useful tool for studying the human body thermoregulatory response.
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Pedrianes-Martin, Pablo B.; Martin-Rincon, Marcos; Morales-Alamo, David; Perez-Suarez, Ismael; Perez-Valera, Mario & Galvan-Alvarez, Victor
[Vis alle 9 forfattere av denne artikkelen]
(2021).
Treatment of hypertension with angiotensin-converting enzyme inhibitors or angiotensin receptor blockers and resting metabolic rate: A cross-sectional study.
The Journal of Clinical Hypertension.
ISSN 1524-6175.
23(12),
s. 2106–2114.
doi:
10.1111/jch.14392.
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Hypertension in obese and overweight patients is associated with an elevated resting metabolic rate (RMR). The aim of this study was to determine whether RMR is reduced in hypertensive patients treated with angiotensin-converting enzyme inhibitors (ACEI) and blockers (ARB). The RMR was determined by indirect calorimetry in 174 volunteers; 93 (46.5 %) were hypertensive, of which 16 men and 13 women were treated with ACEI/ARB, while 30 men and 19 women with untreated hypertension served as a control group. Treated and untreated hypertensives had similar age, BMI, physical activity, and cardiorespiratory fitness. The RMR normalized to the lean body mass (LBM) was 15% higher in the untreated than ACEI/ARB-treated hypertensive women (p = .003). After accounting for LBM, whole-body fat mass, age, the double product (heart rate x systolic blood pressure), and the distance walked per day, the RMR was 2.9% lower in the patients taking ACEI/ARB (p = .26, treatment x sex interaction p = .005). LBM, age, and the double product explained 78% of the variability in RMR (R2 = 0.78, p < .001). In contrast, fat mass, the distance walked per day, and total T4 or TSH did not add predictive power to the model. Compared to men, a greater RMR per kg of LBM was observed in untreated hypertensive overweight and obese women, while this sex difference was not observed in patients treated with ACEI or ARBs. In conclusion, our results indicate that elevated RMR per kg of LBM may be normalized by antagonizing the renin-angiotensin system.
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Rodríguez de Rivera, Pedro Jesús; Rodríguez de Rivera, Miriam; Socorro, Fabiola; Callicó, Gustavo Marrero; Calbet, Jose Antonio Lopez & Rodríguez de Rivera, Manuel
(2021).
Heat flow, heat capacity and thermal resistance of localized surfaces of the human body using a new calorimetric sensor.
Journal of Thermal Analysis and Calorimetry.
ISSN 1388-6150.
doi:
10.1007/s10973-021-11062-0.
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A non-invasive sensor equipped with a programmable thermostat has been developed to assess in vivo the heat flow transmitted by conduction from human skin to the sensor thermostat. This device enables the assessment of the thermal properties of a 2 × 2 cm2 skin surface with a thermal penetration depth of 3–4 mm. In this work, we report the thermal magnitudes recorded with this sensor in 6 different areas (temple, hand, abdomen, thigh, wrist and heel) of 6 healthy subjects of different genders and ages, which were measured under resting conditions. Heat flow and equivalent thermal resistance are proportionally related to each other and are highly variable in magnitude and different for each zone. The heat capacity is also different for each zone. The heat flow values varied from 362 ± 17 mW at the temple to 36 ± 12 mW at the heel for the same subject, when the sensor thermostat was set at 26 °C. The equivalent thermal resistance ranged from 23 ± 2 K W−1 in the volar area of the wrist to 52 ± 4 KW−1 in the inner thigh area. The heat capacity varies from 4.8 ± 0.4 J K−1 in the heel to 6.4 ± 0.2 J K−1 in the abdomen. These magnitudes were also assessed over a 2 × 1 cm2 second-degree burn scar in the volar area of the wrist. The scar area had 27.6 and 11.6% lower heat capacity and equivalent thermal resistance, respectively, allowing an increased heat flow in the injured area. This work is a preliminary study of the measurement capacity of this new instrument.
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Martin-Rincon, Marcos; Gelabert-Rebato, Miriam; Perez-Valera, Mario; Galvan-Alvarez, Victor; Morales-Alamo, David & Dorado, Cecilia
[Vis alle 9 forfattere av denne artikkelen]
(2021).
Functional reserve and sex differences during exercise to exhaustion revealed by post-exercise ischaemia and repeated supramaximal exercise.
Journal of Physiology.
ISSN 0022-3751.
599(16),
s. 3853–3878.
doi:
10.1113/JP281293.
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The purpose of this study was to ascertain what mechanisms explain sex differences at task failure and to determine whether males and females have a functional reserve at exhaustion. Exercise performance, cardiorespiratory variables, oxygen deficit, and brain and muscle oxygenation were determined in 18 males and 18 females (21–36 years old) in two sessions consisting of three bouts of constant-power exercise at 120% of urn:x-wiley:00223751:media:tjp14749:tjp14749-math-0002 until exhaustion interspaced by 20 s recovery periods. In one of the two sessions, the circulation of both legs was occluded instantaneously (300 mmHg) during the recovery periods. Females had a higher muscle O2 extraction during fatiguing supramaximal exercise than males. Metaboreflex activation, and lean mass-adjusted O2 deficit and debt were similar in males and females. Compared to males, females reached lower urn:x-wiley:00223751:media:tjp14749:tjp14749-math-0003 and brain oxygenation during supramaximal exercise, without apparent negative consequences on performance. After the occlusions, males and females were able to restart exercising at 120% of urn:x-wiley:00223751:media:tjp14749:tjp14749-math-0004, revealing a similar functional reserve, which depends on glycolytic component of substrate-level phosphorylation and its rate of utilization. After ischaemia, muscle O2 extraction was increased, and muscle urn:x-wiley:00223751:media:tjp14749:tjp14749-math-0005 was similarly reduced in males and females. The physiological response to repeated supramaximal exercise to exhaustion is remarkably similar in males and females when differences in lean mass are considered. Both sexes fatigue with a large functional reserve, which depends on the glycolytic energy supply, yet females have higher oxygen extraction capacity, but reduced PETCO2 and brain oxygenation.
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Pedrianes-Martin, Pablo B.; Perez-Valera, Mario; Morales-Alamo, David; Martin-Rincon, Marcos; Perez-Suarez, Ismael & Serrano-Sanchez, Jose A.
[Vis alle 12 forfattere av denne artikkelen]
(2021).
Resting metabolic rate is increased in hypertensive patients with overweight or obesity: Potential mechanisms.
Scandinavian Journal of Medicine & Science in Sports.
ISSN 0905-7188.
31(7),
s. 1461–1470.
doi:
10.1111/sms.13955.
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The purpose of this investigation was to determine whether differences in body composition, pharmacological treatment, and physical activity explain the increased resting metabolic rate (RMR) and impaired insulin sensitivity in hypertension. Resting blood pressure, RMR (indirect calorimetry), body composition (dual-energy X-ray absorptiometry), physical activity (accelerometry), maximal oxygen uptake (VO2max) (ergospirometry), and insulin sensitivity (Matsuda index) were measured in 174 patients (88 men and 86 women; 20–68 years) with overweight or obesity. Hypertension (HTA) was present in 51 men (58%) and 42 women (49%) (p = .29). RMR was 6.9% higher in hypertensives than normotensives (1777 ± 386 and 1663 ± 383 kcal d−1, p = .044). The double product (systolic blood pressure × heart rate) was 18% higher in hypertensive than normotensive patients (p < .001). The observed differences in absolute RMR were non-significant after adjusting for total lean mass and total fat mass (estimated means: 1702 kcal d−1, CI: 1656–1750; and 1660 kcal d−1, CI: 1611–1710 kcal d−1, for the hypertensive and normotensive groups, respectively, p = .19, HTA × sex interaction p = .37). Lean mass, the double product, and age were the variables with the higher predictive value of RMR in hypertensive patients. Insulin sensitivity was lower in hypertensive than in normotensive patients, but these differences disappeared after accounting for physical activity and VO2max. In summary, hypertension is associated with increased RMR and reduced insulin sensitivity. The increased RMR is explained by an elevated myocardial oxygen consumption due to an increased resting double product, combined with differences in body composition between hypertensive and normotensive subjects.
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Martinez-Canton, Miriam; Gallego-Selles, Angel; Gelabert-Rebato, Miriam; Martin-Rincon, Marcos; Pareja-Blanco, Fernando & Rodriguez-Rosell, David
[Vis alle 11 forfattere av denne artikkelen]
(2020).
Role of CaMKII and sarcolipin in muscle adaptations to strength training with different levels of fatigue in the set.
Scandinavian Journal of Medicine & Science in Sports.
ISSN 0905-7188.
doi:
10.1111/sms.13828.
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Strength training promotes a IIX‐to‐IIA shift in myosin heavy chain (MHC) composition, likely due to changes in sarcoplasmic [Ca2+] which are sensed by CaMKII. Sarcoplasmic [Ca2+] is in part regulated by sarcolipin (SLN), a small protein that when overexpressed in rodents stimulates mitochondrial biogenesis and a fast‐to‐slow fiber type shift. The purpose of this study was to determine whether CaMKII and SLN are involved in muscle phenotype and performance changes elicited by strength training. Twenty‐two men followed an 8‐week velocity‐based resistance training program using the full squat exercise while monitoring repetition velocity. Subjects were randomly assigned to two resistance training programs differing in the repetition velocity loss allowed in each set: 20% (VL20) vs 40% (VL40). Strength training caused muscle hypertrophy, improved 1RM and increased total CaMKII protein expression, particularly of the δD isoform. Phospho‐Thr287‐CaMKII δD expression increased only in VL40 (+89%), which experienced greater muscle hypertrophy, and a reduction in MHC‐IIX percentage. SLN expression was increased in VL20 (+33%) remaining unaltered in VL40. The changes in phospho‐Thr287‐CaMKII δD were positively associated with muscle hypertrophy and the number of repetitions during training, and negatively with the changes in MHC‐IIX and SLN. Most OXPHOS proteins remained unchanged, except for NDUFB8 (Complex I), which was reduced after training (−22%) in both groups. The amount of fatigue allowed in each set critically influences muscle CaMKII and SLN responses and determines muscle phenotype changes. With lower intra‐set fatigue, the IIX‐to‐IIA MHC shift is attenuated.
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Gallego-Selles, Angel; Martin-Rincon, Marcos; Martinez-Canton, Miriam; Perez-Valera, Mario; Martín-Rodríguez, Saúl & Gelabert-Rebato, Miriam
[Vis alle 10 forfattere av denne artikkelen]
(2020).
Regulation of Nrf2/Keap1 signalling in human skeletal muscle during exercise to exhaustion in normoxia, severe acute hypoxia and post-exercise ischaemia: Influence of metabolite accumulation and oxygenation.
Redox Biology.
ISSN 2213-2317.
36.
doi:
10.1016/j.redox.2020.101627.
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The Nrf2 transcription factor is induced by reactive oxygen and nitrogen species and is necessary for the adaptive response to exercise in mice. It remains unknown whether Nrf2 signalling is activated by exercise in human skeletal muscle. Here we show that Nrf2 signalling is activated by exercise to exhaustion with similar responses in normoxia (PIO2: 143 mmHg) and severe acute hypoxia (PIO2: 73 mmHg). CaMKII and AMPKα phosphorylation were similarly induced in both conditions. Enhanced Nrf2 signalling was achieved by raising Nrf2 total protein and Ser40 Nrf2 phosphorylation, accompanied by a reduction of Keap1. Keap1 protein degradation is facilitated by the phosphorylation of p62/SQSTM1 at Ser349 by AMPK, which targets Keap1 for autophagic degradation. Consequently, the Nrf2-to-Keap1 ratio was markedly elevated and closely associated with a 2-3-fold increase in Catalase protein. No relationship was observed between Nrf2 signalling and SOD1 and SOD2 protein levels. Application of ischaemia immediately at the end of exercise maintained these changes, which were reverted within 1 min of recovery with free circulation. While SOD2 did not change significantly during either exercise or ischaemia, SOD1 protein expression was marginally downregulated and upregulated during exercise in normoxia and hypoxia, respectively. We conclude that Nrf2/Keap1/Catalase pathway is rapidly regulated during exercise and recovery in human skeletal muscle. Catalase emerges as an essential antioxidant enzyme acutely upregulated during exercise and ischaemia. Post-exercise ischaemia maintains Nrf2 signalling at the level reached at exhaustion and can be used to avoid early post-exercise recovery, which is O2-dependent.
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Larsen, Filip J.; Schiffer, Tomas A.; Zinner, Christoph; Willis, Sarah J.; Morales-Alamo, David & Calbet, Jose Antonio Lopez
[Vis alle 8 forfattere av denne artikkelen]
(2020).
Mitochondrial oxygen affinity increases after sprint interval training and is related to the improvement in peak oxygen uptake.
Acta Physiologica.
ISSN 1748-1708.
229(3),
s. 1–9.
doi:
10.1111/apha.13463.
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Aims:
The body responds to exercise training by profound adaptations throughout the cardiorespiratory and muscular systems, which may result in improvements in maximal oxygen consumption (VO2peak) and mitochondrial capacity. By convenience, mitochondrial respiration is often measured at supra‐physiological oxygen levels, an approach that ignores any potential regulatory role of mitochondrial affinity for oxygen (p50mito) at physiological oxygen levels.
Methods:
In this study, we examined the p50mito of mitochondria isolated from the Vastus lateralis and Triceps brachii in 12 healthy volunteers before and after a training intervention with seven sessions of sprint interval training using both leg cycling and arm cranking. The changes in p50mito were compared to changes in whole‐body VO2peak.
Results:
We here show that p50mito is similar in isolated mitochondria from the Vastus (40 ± 3.8 Pa) compared to Triceps (39 ± 3.3) but decreases (mitochondrial oxygen affinity increases) after seven sessions of sprint interval training (to 26 ± 2.2 Pa in Vastus and 22 ± 2.7 Pa in Triceps, both P < .01). The change in VO2peak modelled from changes in p50mito was correlated to actual measured changes in VO2peak (R2 = .41, P = .002).
Conclusion:
Together with mitochondrial respiratory capacity, p50mito is a critical factor when measuring mitochondrial function, it can decrease with sprint interval training and should be considered in the integrative analysis of the oxygen cascade from lung to mitochondria.
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Martin-Rincon, Marcos; Gelabert-Rebato, Miriam; Galvan-Alvarez, Victor; Gallego-Selles, Angel; Martinez-Canton, Miriam & Lopez-Rios, Laura
[Vis alle 14 forfattere av denne artikkelen]
(2020).
Supplementation with a Mango Leaf Extract (Zynamite®) in Combination with Quercetin Attenuates Muscle Damage and Pain and Accelerates Recovery after Strenuous Damaging Exercise.
Nutrients.
ISSN 2072-6643.
12(3),
s. 1–15.
doi:
10.3390/nu12030614.
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Prolonged or unusual exercise may cause exercise-induced muscle damage (EIMD). To test whether Zynamite®, a mango leaf extract rich in the natural polyphenol mangiferin, administered in combination with quercetin facilitates recovery after EIMD, 24 women and 33 men were randomly assigned to two treatment groups matched by sex and 5 km running performance, and ran a 10 km race followed by 100 drop jumps to elicit EIMD. One hour before the competition, and every 8 h thereafter for 24 h, they ingested placebo (728 mg of maltodextrin) or 140 mg of Zynamite® combined with 140 mg of quercetin (double-blind). Although competition times were similar, polyphenol supplementation attenuated the muscle pain felt after the competition (6.8 ± 1.5 and 5.7 ± 2.2 a.u., p = 0.035) and the loss of jumping performance (9.4 ± 11.5 and 3.9 ± 5.2%, p = 0.036; p = 0.034) and mechanical impulse (p = 0.038) 24 h later. The polyphenols attenuated the increase of serum myoglobin and alanine aminotransferase in men, but not in women (interaction p < 0.05). In conclusion, a single dose of 140 mg Zynamite® combined with 140 mg of quercetin, administered one hour before competition, followed by three additional doses every eight hours, attenuates muscle pain and damage, and accelerates the recovery of muscle performance.
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Skattebo, Øyvind; Calbet, Jose Antonio Lopez; Rud, Bjarne; Capelli, Carlo & Hallén, Jostein
(2020).
Contribution of oxygen extraction fraction to maximal oxygen uptake in healthy young men.
Acta Physiologica.
ISSN 1748-1708.
230(2).
doi:
10.1111/apha.13486.
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We analysed the importance of systemic and peripheral arteriovenous O2 difference ( urn:x-wiley:17481708:media:apha13486:apha13486-math-0001 difference and a‐vfO2 difference, respectively) and O2 extraction fraction for maximal oxygen uptake ( urn:x-wiley:17481708:media:apha13486:apha13486-math-0002). Fick law of diffusion and the Piiper and Scheid model were applied to investigate whether diffusion versus perfusion limitations vary with urn:x-wiley:17481708:media:apha13486:apha13486-math-0003. Articles (n = 17) publishing individual data (n = 154) on urn:x-wiley:17481708:media:apha13486:apha13486-math-0004, maximal cardiac output ( urn:x-wiley:17481708:media:apha13486:apha13486-math-0005; indicator‐dilution or the Fick method), urn:x-wiley:17481708:media:apha13486:apha13486-math-0006 difference (catheters or the Fick equation) and systemic O2 extraction fraction were identified. For the peripheral responses, group‐mean data (articles: n = 27; subjects: n = 234) on leg blood flow (LBF; thermodilution), a‐vfO2 difference and O2 extraction fraction (arterial and femoral venous catheters) were obtained. urn:x-wiley:17481708:media:apha13486:apha13486-math-0007 and two‐LBF increased linearly by 4.9‐6.0 L · min–1 per 1 L · min–1 increase in urn:x-wiley:17481708:media:apha13486:apha13486-math-0008 (R2 = .73 and R2 = .67, respectively; both P < .001). The urn:x-wiley:17481708:media:apha13486:apha13486-math-0009 difference increased from 118‐168 mL · L–1 from a urn:x-wiley:17481708:media:apha13486:apha13486-math-0010 of 2‐4.5 L · min–1 followed by a reduction (second‐order polynomial: R2 = .27). After accounting for a hypoxemia‐induced decrease in arterial O2 content with increasing urn:x-wiley:17481708:media:apha13486:apha13486-math-0011 (R2 = .17; P < .001), systemic O2 extraction fraction increased up to ~90% ( urn:x-wiley:17481708:media:apha13486:apha13486-math-0012: 4.5 L · min–1) with no further change (exponential decay model: R2 = .42). Likewise, leg O2 extraction fraction increased with urn:x-wiley:17481708:media:apha13486:apha13486-math-0013 to approach a maximal value of ~90‐95% (R2 = .83). Muscle O2 diffusing capacity and the equilibration index Y increased linearly with urn:x-wiley:17481708:media:apha13486:apha13486-math-0014 (R2 = .77 and R2 = .31, respectively; both P < .01), reflecting decreasing O2 diffusional limitations and accentuating O2 delivery limitations. In conclusion, although O2 delivery is the main limiting factor to urn:x-wiley:17481708:media:apha13486:apha13486-math-0015, enhanced O2 extraction fraction (≥90%) contributes to the remarkably high urn:x-wiley:17481708:media:apha13486:apha13486-math-0016 in endurance‐trained individuals.
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Martin-Rincon, Marcos & Calbet, Jose Antonio Lopez
(2020).
Progress Update and Challenges on VO<inf>2max</inf> Testing and Interpretation.
Frontiers in Physiology.
ISSN 1664-042X.
11.
doi:
10.3389/fphys.2020.01070.
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The maximal oxygen uptake (V.O2max) is the primary determinant of endurance performance in heterogeneous populations and has predictive value for clinical outcomes and all-cause mortality. Accurate and precise measurement of V.O2max requires the adherence to quality control procedures, including combustion testing and the use of standardized incremental exercise protocols with a verification phase preceded by an adequate familiarization. The data averaging strategy employed to calculate the V.O2max from the breath-by-breath data can change the V.O2max value by 4–10%. The lower the number of breaths or smaller the number of seconds included in the averaging block, the higher the calculated V.O2max value with this effect being more prominent in untrained subjects. Smaller averaging strategies in number of breaths or seconds (less than 30 breaths or seconds) facilitate the identification of the plateau phenomenon without reducing the reliability of the measurements. When employing metabolic carts, averaging intervals including 15–20 breaths or seconds are preferable as a compromise between capturing the true V.O2max and identifying the plateau. In training studies, clinical interventions and meta-analysis, reporting of V.O2max in absolute values and inclusion of protocols and the averaging strategies arise as imperative to permit adequate comparisons. Newly developed correction equations can be used to normalize V.O2max to similar averaging strategies. A lack of improvement of V.O2max with training does not mean that the training program has elicited no adaptations, since peak cardiac output and mitochondrial oxidative capacity may be increased without changes in V.O2max.
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Skattebo, Øyvind; Capelli, Carlo; Rud, Bjarne; Auensen, Marius; Calbet, Jose Antonio Lopez & Hallén, Jostein
(2020).
Increased oxygen extraction and mitochondrial protein expression after small muscle mass endurance training.
Scandinavian Journal of Medicine & Science in Sports.
ISSN 0905-7188.
30(9),
s. 1615–1631.
doi:
10.1111/sms.13707.
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When exercising with a small muscle mass, the mass‐specific O2 delivery exceeds the muscle oxidative capacity resulting in a lower O2 extraction compared with whole‐body exercise. We elevated the muscle oxidative capacity and tested its impact on O2 extraction during small muscle mass exercise. Nine individuals conducted six weeks of one‐legged knee extension (1L‐KE) endurance training. After training, the trained leg (TL) displayed 45% higher citrate synthase and COX‐IV protein content in vastus lateralis and 15%‐22% higher pulmonary oxygen uptake ( urn:x-wiley:09057188:media:sms13707:sms13707-math-0001) and peak power output ( urn:x-wiley:09057188:media:sms13707:sms13707-math-0002) during 1L‐KE than the control leg (CON; all P < .05). Leg O2 extraction (catheters) and blood flow (ultrasound Doppler) were measured while both legs exercised simultaneously during 2L‐KE at the same submaximal power outputs (real‐time feedback‐controlled). TL displayed higher O2 extraction than CON (main effect: 1.7 ± 1.6% points; P = .010; 40%‐83% of urn:x-wiley:09057188:media:sms13707:sms13707-math-0003) with the largest between‐leg difference at 83% of urn:x-wiley:09057188:media:sms13707:sms13707-math-0004 (O2 extraction: 3.2 ± 2.2% points; arteriovenous O2 difference: 7.1 ± 4.8 mL· L−1; P < .001). At 83% of urn:x-wiley:09057188:media:sms13707:sms13707-math-0005, muscle O2 conductance (DMO2; Fick law of diffusion) and the equilibration index Y were higher in TL (P < .01), indicating reduced diffusion limitations. The between‐leg difference in O2 extraction correlated with the between‐leg ratio of citrate synthase and COX‐IV (r = .72‐.73; P = .03), but not with the difference in the capillary‐to‐fiber ratio (P = .965). In conclusion, endurance training improves O2 extraction during small muscle mass exercise by elevating the muscle oxidative capacity and the recruitment of DMO2, especially evident during high‐intensity exercise exploiting a larger fraction of the muscle oxidative capacity.
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Calbet, Jose Antonio Lopez; Martín-Rodríguez, Saúl; Martin-Rincon, Marcos & Morales-Alamo, David
(2020).
An integrative approach to the regulation of mitochondrial respiration during exercise: Focus on high-intensity exercise.
Redox Biology.
ISSN 2213-2317.
35.
doi:
10.1016/j.redox.2020.101478.
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During exercise, muscle ATP demand increases with intensity, and at the highest power output, ATP consumption may increase more than 100-fold above the resting level. The rate of mitochondrial ATP production during exercise depends on the availability of O2, carbon substrates, reducing equivalents, ADP, Pi, free creatine, and Ca2+. It may also be modulated by acidosis, nitric oxide and reactive oxygen and nitrogen species (RONS). During fatiguing and repeated sprint exercise, RONS production may cause oxidative stress and damage to cellular structures and may reduce mitochondrial efficiency. Human studies indicate that the relatively low mitochondrial respiratory rates observed during sprint exercise are not due to lack of O2, or insufficient provision of Ca2+, reduced equivalents or carbon substrates, being a suboptimal stimulation by ADP the most plausible explanation. Recent in vitro studies with isolated skeletal muscle mitochondria, studied in conditions mimicking different exercise intensities, indicate that ROS production during aerobic exercise amounts to 1-2 orders of magnitude lower than previously thought. In this review, we will focus on the mechanisms regulating mitochondrial respiration, particularly during high-intensity exercise. We will analyze the factors that limit mitochondrial respiration and those that determine mitochondrial efficiency during exercise. Lastly, the differences in mitochondrial respiration between men and women will be addressed.
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Martin-Rincon, Marcos; Pérez-López, Antonio; Morales-Alamo, David; Perez-Suarez, Ismael; de Pablos-Velasco, Pedro & Perez-Valera, Mario
[Vis alle 12 forfattere av denne artikkelen]
(2019).
Exercise mitigates the loss of muscle mass by attenuating the activation of autophagy during severe energy deficit.
Nutrients.
ISSN 2072-6643.
11:2824(11),
s. 1–26.
doi:
10.3390/nu11112824.
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The loss of skeletal muscle mass with energy deficit is thought to be due to protein breakdown by the autophagy-lysosome and the ubiquitin-proteasome systems. We studied the main signaling pathways through which exercise can attenuate the loss of muscle mass during severe energy deficit (5500 kcal/day). Overweight men followed four days of caloric restriction (3.2 kcal/kg body weight day) and prolonged exercise (45 min of one-arm cranking and 8 h walking/day), and three days of control diet and restricted exercise, with an intra-subject design including biopsies from muscles submitted to distinct exercise volumes. Gene expression and signaling data indicate that the main catabolic pathway activated during severe energy deficit in skeletal muscle is the autophagy-lysosome pathway, without apparent activation of the ubiquitin-proteasome pathway. Markers of autophagy induction and flux were reduced by exercise primarily in the muscle submitted to an exceptional exercise volume. Changes in signaling are associated with those in circulating cortisol, testosterone, cortisol/testosterone ratio, insulin, BCAA, and leucine. We conclude that exercise mitigates the loss of muscle mass by attenuating autophagy activation, blunting the phosphorylation of AMPK/ULK1/Beclin1, and leading to p62/SQSTM1 accumulation. This includes the possibility of inhibiting autophagy as a mechanism to counteract muscle loss in humans under severe energy deficit.
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Martin-Rincon, Marcos; Gonzalez-Henriquez, Juan Jose; Losa-Reyna, Jose; Perez-Suarez, Ismael; Ponce-Gonzalez, Jesus Gustavo & de La Calle-Herrero, Jaime
[Vis alle 12 forfattere av denne artikkelen]
(2019).
Impact of data averaging strategies on V̇O2max assessment: Mathematical modeling and reliability .
Scandinavian Journal of Medicine & Science in Sports.
ISSN 0905-7188.
29(10),
s. 1473–1488.
doi:
10.1111/sms.13495.
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Background:
No consensus exists on how to average data to optimize VO2max assessment. Although the VO2max value is reduced with larger averaging blocks, no mathematical procedure is available to account for the effect of the length of the averaging block on VO2max.
Aims:
To determine the effect that the number of breaths or seconds included in the averaging block has on the VO2max value and its reproducibility and to develop correction equations to standardize VO2max values obtained with different averaging strategies.
Methods:
Eighty‐four subjects performed duplicate incremental tests to exhaustion (IE) in the cycle ergometer and/or treadmill using two metabolic carts (Vyntus and Vmax N29). Rolling breath averages and fixed time averages were calculated from breath‐by‐breath data from 6 to 60 breaths or seconds.
Results:
VO2max decayed from 6 to 60 breath averages by 10% in low fit (VO2max < 40 mL kg−1 min−1) and 6.7% in trained subjects. The VO2max averaged from a similar number of breaths or seconds was highly concordant (CCC > 0.97). There was a linear‐log relationship between the number of breaths or seconds in the averaging block and VO2max (R2 > 0.99, P < 0.001), and specific equations were developed to standardize VO2max values to a fixed number of breaths or seconds. Reproducibility was higher in trained than low‐fit subjects and not influenced by the averaging strategy, exercise mode, maximal respiratory rate, or IE protocol.
Conclusions:
The VO2max decreases following a linear‐log function with the number of breaths or seconds included in the averaging block and can be corrected with specific equations as those developed here.
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Sanchis-Moysi, Joaquin; Serrano-Sanchez, Jose Antonio; Gonzalez-Henriquez, Juan Jose; Calbet, Jose Antonio Lopez & Dorado, Cecilia
(2019).
Greater Reduction in Abdominal Than in Upper Arms Subcutaneous Fat in 10- to 12-Year-Old Tennis Players: A Volumetric MRI Study.
Frontiers in pediatrics.
ISSN 2296-2360.
7.
doi:
10.3389/fped.2019.00345.
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Background: Little is known about the impact of long term participation in sports and subcutaneous fat volume in children. This study aimed at determining whether tennis participation is associated with lower subcutaneous adipose tissue volume (SATv) in the abdominal and upper extremities in children.
Methods: Magnetic resonance imaging (MRI) was used to determine the SATv stored in the abdominal region and upper arms in seven tennis players and seven inactive children matched by height and age (147 cm and 10.9 years). All participants were in Tanner stage 1 or 2.
Results: Playing tennis was associated with 48% (P = 0.001) lower abdominal SATv and 17–18% (P > 0.05) lower upper arms SATv compared to controls. The ratio between abdominal/upper arms SATv was larger in the controls vs. tennis players (69% P = 0.001). The SATv was similar in the dominant and non-dominant arm within each group.
Conclusion: Playing tennis during childhood is associated with reduced SATv in the abdominal region and a more favorable regional distribution of fat. Despite the large amount of contractile activity of the playing (dominant) arm, there was no indication of between-arms differences in SATv.
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Publisert
17. okt. 2023 13:10
- Sist endret
13. des. 2023 14:36
