Fig. 1.

Study design for the analysis of effects of resistance exercise (RE) and progressive resistance training (PRT) on vastus lateralis gene expression. Young and old adults of study A performed an acute bout of RE (3 × 10 repetitions at 70–75% of 1 repetition maximum) in the untrained and trained state. Muscle biopsies were collected pre and 4 h after the RE bout. In young and old women myosin heavy chain (MHC) I and IIa muscle fibers (pools of 20 fibers) were isolated and analyzed for gene expression response to RE.