Resistance training in young men induces muscle transcriptome-wide changes associated with muscle structure and metabolism refining the response to exercise-induced stress.

Abstract

Gene expression is an important process underpinning the acute and chronic adaptive response to resistance exercise (RE) training. To investigate the effect of training status on vastus lateralis muscle global transcriptome at rest and following acute RE. Muscle biopsies of nine young men (age: 26(2)years; body mass: 69(9)kg; height 172(6)cm) who undertook RE training for 10weeks were collected pre and 24h post-RE in the untrained (W1) and trained (W10) states and analysed using microarray. Tests of differential expression were conducted for rested and after RE contrasts in both training states. To control for false discovery rate (FDR), multiple testing correction was performed at a cut-off of FDR < 0.05. Unaccustomed RE (at W1) upregulated muscle gene transcripts related to stress (e.g., heat shock proteins), damage and inflammation, structural remodelling, protein turnover and increased translational capacity. Trained muscles (at W10) showed changes in the transcriptome signature regarding the regulation of energy metabolism, favouring a more oxidative one, upregulated antioxidant- and immune-related genes/terms, and gene transcripts related to the cytoskeleton and extracellular matrix, muscle contraction, development and growth. These results highlight that chronic repetition of RE changes muscle transcriptome response towards a more refined response to RE-induced stress.