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Avertissement : âmes sensibles, ne pas regarder cette vidéo
moins de 18 ans :  ne pas regarder cette vidéo

Réalités et fictions concernant les accidents du… par GUNDILL

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Massage Therapy Attenuates Inflammatory Signaling After Exercise-Induced Muscle Damage
Sci Transl Med 1 February 2012: Vol. 4, Issue 119, p. 119ra13     Justin D. Crane

Massage therapy is commonly used during physical rehabilitation of skeletal muscle to ameliorate pain and promote recovery from injury. Although there is evidence that massage may relieve pain in injured muscle, how massage affects cellular function remains unknown. To assess the effects of massage, we administered either massage therapy or no treatment to separate quadriceps of 11 young male participants after exercise-induced muscle damage. Muscle biopsies were acquired from the quadriceps (vastus lateralis) at baseline, immediately after 10 min of massage treatment, and after a 2.5-hour period of recovery. We found that massage activated the mechanotransduction signaling pathways focal adhesion kinase (FAK) and extracellular signal–regulated kinase 1/2 (ERK1/2), potentiated mitochondrial biogenesis signaling [nuclear peroxisome proliferator–activated receptor γ coactivator 1α (PGC-1α)], and mitigated the rise in nuclear factor κB (NFκB) (p65) nuclear accumulation caused by exercise-induced muscle trauma. Moreover, despite having no effect on muscle metabolites (glycogen, lactate), massage attenuated the production of the inflammatory cytokines tumor necrosis factor–α (TNF-α) and interleukin-6 (IL-6) and reduced heat shock protein 27 (HSP27) phosphorylation, thereby mitigating cellular stress resulting from myofiber injury. In summary, when administered to skeletal muscle that has been acutely damaged through exercise, massage therapy appears to be clinically beneficial by reducing inflammation and promoting mitochondrial biogenesis.

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L’athlète master d’endurance, un modèle de vieillissement réussi
Science & Sports 2012 Louis J

Objectifs
Cet article vise à présenter l’athlète master d’endurance à travers ses caractéristiques physiologiques et passe en revue l’effet de l’âge sur les principaux facteurs de la performance en endurance.

Actualités
Le déclin de la performance physique est inévitable avec l’avancée dans l’âge. Néanmoins, certaines personnes âgées continuent à s’entraîner autant que leurs homologues plus jeunes afin de repousser les effets du vieillissement. Ces « athlètes masters » présentent très peu d’altérations physiques, sont capables de performances remarquables dans les épreuves d’endurance et constituent ainsi de véritables modèles de vieillissement réussi. L’activité physique régulière leur permet de limiter l’altération des capacités physiologiques nécessaires à une bonne qualité de vie.

Perspectives
L’athlète master constitue un modèle expérimental intéressant dans l’étude du vieillissement, sans les effets confondus d’un mode de vie sédentaire et du déconditionnement qui accentuent le processus de vieillissement. Les recherches futures devraient ainsi inclure les athlètes masters afin d’enrichir les connaissances sur le processus de vieillissement et sur les stratégies bénéfiques pour bien vieillir.

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Après, tu passes à la muscu, et tu te fais mal partout

Expression of extracellular matrix components and related growth factors in human tendon and muscle after acute exercise
K. M. Heinemeier, S. S. Bjerrum, P. Schjerling, M. Kjaer
Scandinavian Journal of Medicine & Science in Sports Early View

Acute kicking exercise induces collagen synthesis in both tendon and muscle in humans, but it is not known if this relates to increased collagen transcription and if other matrix genes are regulated. Young men performed 1 h of one-leg kicking at 67% of max workload. Biopsies were taken from the patellar tendon and vastus lateralis muscle of each leg at 2 (n = 10), 6 (n = 11), or 26 h (n = 10) after exercise. Levels of messenger ribonucleic acid mRNA for collagens, noncollagenous matrix proteins, and growth factors were measured with real-time reverse transcription polymerase chain reaction. In tendon, gene expression was unchanged except for a decrease in insulin-like growth factor-IEa (IGF-IEa; P < 0.05). In muscle, collagen expression was not significantly altered, while levels of connective tissue growth factor (CTGF), IGF-IEa, transforming growth factor-β1, -2 (TGF-β), and the TGF-β receptor II mRNA were increased (P < 0.05). Matrix components tenascin-C, fibronectin, and decorin were also induced in loaded muscle (P < 0.05), while fibromodulin was unaffected. In conclusion, the relatively robust changes in matrix components and related growth factors in muscle indicate a stimulation of extracellular matrix even with moderate exercise. However, in tendon tissue, this exercise model does not appear to induce any anabolic response on the transcriptional level.

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