Pre- versus post-exercise protein intake has similar effects on muscular adaptations.
Level 2 - randomized trial
Individual randomized trial
PubMed 28070459 · doi:10.7717/peerj.2825
What was done
Twenty-one resistance-trained men (>1 year experience) were randomized to consume a supplement containing 25 g protein and 1 g carbohydrate either immediately before (PRE-SUPP, n = 9) or immediately after (POST-SUPP, n = 12) resistance training sessions. The training protocol consisted of a 10-week, 3-day-per-week total-body resistance training program (3 sets of 8–12 repetitions per exercise). Muscle strength, hypertrophy, and body composition changes were evaluated.
What was found
The abstract reports no numerical values or effect sizes for strength, hypertrophy, or body composition. It reports only that pre- and post-workout protein intake had similar effects across all measured parameters, with no statistically significant differences between groups (p > 0.05).
Why it matters
The findings challenge the necessity of a narrow, immediate post-exercise "anabolic window," suggesting that consuming protein immediately pre-workout yields comparable adaptations to immediate post-workout intake.
Limits
The sample size was very small (n = 21 total; 9 vs 12), creating high risk for Type II errors on subtle differences. The trial included only young, resistance-trained men, limiting generalizability to women, older adults, or untrained populations. The abstract does not report baseline dietary intake, total daily protein intake, or specific outcome numbers.