| Zdroj: |
Agergaard, J, Reitelseder, S, Pedersen, T G, Doessing, S, Schjerling, P, Langberg, H, Miller, B F, Aagaard, P, Kjaer, M & Holm, L 2013, ' Myogenic, matrix, and growth factor mRNA expression in human skeletal muscle : effect of contraction intensity and feeding ', Muscle & Nerve, vol. 47, no. 5, pp. 748-759 . https://doi.org/10.1002/mus.23667 |
| Popis: |
Introduction: We examined short-term (3-hour) and long-term (12-week) training effects after heavy load [HL; 70% 1RM] and light load (LL; 16% 1RM) exercise. Methods: mRNA expression of genes involved in skeletal muscle remodeling were analyzed and muscle activity (EMG measurements) was measured. Results: Relative muscle activity differed between HL and LL resistance exercise, whereas median power frequency was even, suggesting an equal muscle-fiber-type recruitment distribution. mRNA expression of Myf6, myogenin, and p21 was mostly increased, and myostatin was mostly depressed by HL resistance exercise. No major differences were seen in atrophy-related genes between HL and LL resistance exercise. No changes were seen over 12-week training for any of the targets. Conclusions: Resistance exercise at LL and HL elevated the expression of genes involved in skeletal muscle hypertrophy, although the greatest response was from HL. However, no long-term effect from either LL or HL resistance exercise was seen on basal levels of the mRNA targets. |
