Resistance exercise with whey protein ingestion affects mTOR signaling pathway and myostatin in men.

Signaling pathways sense local and systemic signals and regulate muscle hypertrophy. The effects of whey protein ingestion on acute and long-term signaling responses of resistance exercise are not well known. Previously untrained young men were randomized into protein ( n = 9), placebo ( n = 9), and control ( n = 11) groups. Vastus lateralis (VL) muscle biopsies were taken before and 1 h and 48 h after a leg press of 5 × 10 repetitions [resistance exercise (RE)] and after 21 wk (2 times per week) of resistance training (RT). Protein (15 g of whey) or nonenergetic placebo was ingested before and after a single RE bout and each RE workout throughout the RT. The protein group increased its bo…