Vilde Handegard

• Wiig, Håvard; Cumming, Kristoffer Toldnes; Handegard, Vilde; Stabell Hansen, Jostein; Spencer, Matthew & Raastad, Truls (2022). Muscular heat shock protein response and muscle damage after semi-professional football match. Scandinavian Journal of Medicine & Science in Sports. ISSN 0905-7188. 32(6), s. 984–996. doi: 10.1111/sms.14148. Vis sammendrag

  Purpose: A typical football match leads to neuromuscular fatigue and physical performance impairments up to 72–96 h post-match. While muscle damage is thought to be a major factor, damage on the ultrastructural level has never been documented. The purpose of this study was to investigate post-match cellular muscle damage by quantifying the heat shock protein (HSP) response as a proxy for protein damage. Methods: Muscle biopsies, blood samples, countermovement jumps, and perception of muscle soreness were obtained from twelve semi-professional football players 1, 24, 48, and 72 h after a 90-min football match. Muscle biopsies were analyzed for αB-crystallin and HSP70 in the cytosolic and cytoskeletal sub-cellular fractions by Western blotting. Fiber type-specific αB-crystallin and HSP70 staining intensity, and tenascin-C immunoreactivity were analyzed with immunohistochemistry. Blood samples were analyzed for creatine kinase and myoglobin. Results: Within 24 h post-match, a 2.7- and 9.9-fold increase in creatine kinase and myoglobin were observed, countermovement jump performance decreased by −9.7% and muscle soreness increased by 0.68 units. αB-crystallin and HSP70 accumulated in cytoskeletal structures evident by a 3.6- and 1.8-fold increase in the cytoskeletal fraction and a parallel decrease in the cytosolic fraction. In type I and II fibers, αB-crystallin staining intensity increased by 15%–41% and remained elevated at 72 h post-match. Lastly, the percentage of fibers with granular staining of αB-crystallin increased 2.2-fold. Conclusions: Football match play induced a muscular HSP stress response 1–72 h post-match. Specifically, the accumulation of HSPs in cytoskeletal structures and the granular staining of αB-crystallin suggests occurrence of ultrastructural damage. The damage, indicated by the HSP response, might be one reason for the typically 72 h decrease in force-generating capacity after football matches.

• Aas, Sigve Nyvik; Hamarsland, Håvard; Cumming, Kristoffer Toldnes; Rognlien, Simen Helset; Aase, Ole Jølle & Nordseth, Martin [Vis alle 11 forfattere av denne artikkelen] (2019). The impact of age and frailty on skeletal muscle autophagy markers and T specific strength: A cross-sectional comparison. Experimental Gerontology. ISSN 0531-5565. 125. doi: 10.1016/j.exger.2019.110687. Vis sammendrag

  Aging is associated with reduced specific strength, defined as strength normalized to the cross-sectional area of a given muscle or muscle group. Dysregulated autophagy, impairing removal of dysfunctional proteins and organelles, is suggested as one of the underlying mechanisms. The aim of this study was to investigate levels of autophagic markers in skeletal muscle in groups known to differ in specific strength. Sixty-two volunteers were assigned to the following study groups: young, old non-frail, old pre-frail, and old frail individuals. Leg lean mass was assessed with dual-energy X-ray absorptiometry and quadriceps femoris muscle strength by isometric maximal voluntary contraction. The abundance of autophagic proteins within skeletal muscle cytosolic and membrane sub-fractions were determined by western blotting. In addition, the level of heat shock proteins and proteins involved in the regulation of protein synthesis were measured. The abundance of LC3-I was higher in old frail compared to young individuals. If the three elderly groups were pooled, the level of LC3-II was higher in old compared to young subjects. Pre-frail and frail elderly also displayed higher levels of certain heat shock proteins. No between-group differences were observed for p62, LC3-II/LC3-I ratio, or any of the anabolic signaling molecules. A negative correlation was observed between cytosolic LC3-I and specific strength. Higher levels of LC3-I in the frail elderly might represent attenuated autophagosome formation. However, higher LC3-II levels indicate an increased abundance of autophagosomes. These findings may therefore imply that both the process of autophagosome formation and autophagosome-lysosome fusion are affected in frail elderly. Higher levels of heat shock proteins might represent an auto-protective mechanism against increased levels of misfolded proteins, possibly due to inefficient degradation. In conclusion, the reduction in specific strength with aging and frailty may partly be caused by alterations in muscle protein quality control.

• Hamarsland, Håvard; Handegard, Vilde; Kåshagen, Mauritz; Benestad, Haakon Breien & Raastad, Truls (2019). No Difference Between Spray Dried Milk and Native Whey Supplementation with Strength Training. Medicine & Science in Sports & Exercise. ISSN 0195-9131. 51(1), s. 75–83. doi: 10.1249/MSS.0000000000001758. Fulltekst i vitenarkiv Vis sammendrag

  Background: A rapid digestibility and high leucine content are considered important for maximal stimulation of muscle protein synthesis. Consequently, with these properties, native whey may hold greater anabolic potential than milk, when supplemented in combination with strength training. Our aim was to compare the effects of supplementation with milk or native whey, during a 12-week strength training period, on gains in muscle mass and strength in young adults. Methods: In this double-blinded, randomized, controlled study a total of 40 untrained young men and women received two daily servings of either milk or native whey containing 20 g of protein, during a 12-week strength training intervention. Muscle strength, lean mass, thigh muscle cross sectional area, m. vastus lateralis thickness and muscle fiber cross sectional area were assessed before and after the training period. In addition, the acute phosphorylation of the anabolic kinases p70S6K, 4E-BP1 and eEF-2 in response to a standardized workout and supplementation was investigated before and after the 12-week training period. Results: Muscle mass and strength increased, by all measures applied (5-16%, P < 0.001), with no differences between groups (P > 0.25). p70S6K phosphorylation increased (~1000%, P < 0.02) 2 hours after exercise in the untrained and trained state, but no differences in anabolic signaling were observed between supplements (P > 0.40). No correlation between these acute measures and changes in muscle mass or strength were observed. Conclusion: Supplementation with milk or native whey during a 12-week strength training period did not differentially affect muscle mass and strength in young untrained individuals.

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