Myogenic, matrix and growth factor mRNA expression in human skeletal muscle: effect of contraction intensity and feeding

Research output: Contribution to journalJournal articleResearchpeer-review

Jakob Agergaard, Søren Reitelseder, T.G. Pedersen, Simon Doessing, Peter Schjerling, Henning Langberg, Benjamin F Miller, P Aagaard, Michael Kjær, Lars Holm


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.
Original languageEnglish
JournalMuscle & Nerve
Volume47
Issue number5
Pages (from-to)748-759
Number of pages12
ISSN0148-639X
DOIs
Publication statusPublished - 20 Mar 2013

ID: 129774691