Description:
<jats:sec><jats:label /><jats:p>The acute influence of aerobic exercise on muscle protein turnover is not well defined. The purpose of this study was to examine the influence of moderate intensity aerobic exercise on muscle protein synthesis in the fasted and fed states. Eight recreationally active males (23±2yr, 74±3kg, VO<jats:sub>2</jats:sub>max: 52±2 ml·kg<jats:sup>−1</jats:sup>·min<jats:sup>−1</jats:sup>) performed 60min of cycle ergometry at 72±1% VO<jats:sub>2</jats:sub>max on two occasions in a counter‐balanced design. Trials differed only in a post‐exercise nutritional intervention. Subjects ingested a non‐caloric placebo (FAST) beverage or a beverage containing (per kg body weight): 5kcal, 0.83g carbohydrate, 0.37g protein and 0.28g fat (FED) immediately and 1h after exercise. Mixed muscle protein synthesis (FSR) was assessed at rest and following exercise with the use of an L‐[ring D<jats:sub>5</jats:sub>]‐phenylalanine infusion combined with muscle biopsies at 2 and 6h post‐exercise. Mixed muscle FSR was higher (P<0.05) after exercise in both FAST (0.112 ± 0.010%·h<jats:sup>−1</jats:sup>) and FED (0.129 ± 0.014 %·h<jats:sup>−1</jats:sup>) trials as compared to rest (0.071 ± 0.005 %·h<jats:sup>−1</jats:sup>). These data demonstrate that a moderate intensity, non‐exhaustive bout of aerobic exercise stimulates skeletal muscle FSR in the fasted state. Additionally, post‐exercise feeding did not further enhance FSR after aerobic exercise.</jats:p><jats:p>Supported by a grant from the Gatorade Sports Science Institute</jats:p></jats:sec>