The Effects Of A Relative Dose Of Pre-sleep Protein On Recovery Following Evening Resistance Exercise

Pre-sleep consumption of protein has been shown to enhance recovery of muscle function after evening exercise. Previous studies have primarily compared casein protein (CP) to carbohydrate (CHO), however, less data exists examining the effects of a blend of CP and whey protein (WP; (CP+WP)) or a dose relative to an individual’s lean body mass (LBM). PURPOSE: To assess the acute effects of pre-sleep consumption of isocaloric CP, CP+WP, or CHO at a dose relative to LBM on recovery following an evening lower-body resistance exercise (RE) bout. METHODS: Fifteen active males (age: 21±1yrs, body fat:14.2±2.7%) participated in this randomized, double-blind, crossover study. One-repetition maximums were performed on the leg press and extension machines to determine RE intensity. Participants performed an evening (1600-1900) lower-body RE bout and were provided with 0.4g/kg/LBM WP supplement post RE. A single dose of 0.6g/kg/LBM of CP, 0.4g/kg/LBM CP and 0.2g/kg/LBM WP (CP+WP), or CHO was consumed 30 minutes prior to sleep and each trial was separated by 72 hours. Measurements of perceived recovery (visual analogue scales (VAS) for recovery, soreness and fatigue), appetite (VAS for hunger, satiety and desire to eat), as well as pressure-pain threshold (dolorimeter) and average power (Biodex™) of the right thigh muscles were assessed the following morning. ANOVAs were used for analyses and significance was accepted at p < 0.05. RESULTS: There was no significant difference in perceived morning recovery, soreness and fatigue between pre-sleep supplements. There was a significant difference in pressure-pain threshold at the rectus femoris (p=0.001), vastus medialis (p=0.001) and vastus lateralis (p<0.001). Both CP (98.0±17.3N), and CP+WP (98.2±21.7N) had a greater pressure-pain threshold (i.e. less soreness) than the PLA (80.6±21.7N) at the rectus femoris. Average power was similar between supplements. Hunger was significantly greater after CP than CP+WP (52.2±17.2 vs. 39.9±15.9 mm; p= 0.048). There was no difference for satiety and desire to eat. CONCLUSIONS: Pre-sleep consumption of CP and CP+WP at a dose relative to LBM may enhance overnight recovery to a greater extent than CHO as a result of less muscle soreness the following morning after an acute evening RE bout.