Timing and distribution of protein ingestion during prolonged recovery from resistance exercise alters myofibrillar protein synthesis.
Level 2 - randomized trial
Individual randomized controlled trial in humans
PubMed 23459753 · doi:10.1113/jphysiol.2012.244897
What was done
Twenty-four healthy, resistance-trained males performed a bout of resistance exercise and were randomized to one of three 12-hour recovery feeding protocols, each providing a total of 80 g of whey protein: 8 × 10 g every 1.5 h (PULSE), 4 × 20 g every 3 h (INT), or 2 × 40 g every 6 h (BOLUS; n = 8 per group). Skeletal muscle biopsies were taken at rest and at 1, 4, 6, 7, and 12 h post-exercise to measure myofibrillar protein synthesis (MPS) via L-[ring-13C6] phenylalanine tracer, along with intramuscular cell signaling and mRNA expression.
What was found
All three protocols elevated MPS above resting levels across the 1–12 h recovery window (88% to 148% increase, P < 0.02). The intermediate feeding pattern (INT, 20 g every 3 h) stimulated significantly greater MPS than either PULSE or BOLUS patterns (31% to 48% higher MPS, P < 0.02). Intracellular anabolic signaling phosphorylation followed a BOLUS > INT > PULSE hierarchy, and differential expression of MuRF-1 and SLC38A2 mRNA occurred in the BOLUS group.
Why it matters
These findings show that how total protein intake is distributed across recovery modulates muscle protein accretion independently of total protein dose, supporting moderate, repeated feedings (such as ~20 g every 3 h) to maximize post-exercise anabolic responses.
Limits
The study sample was small (8 men per arm) and restricted strictly to young, trained males. The trial evaluated acute 12-hour fractional synthetic rates using isolated whey protein drinks rather than whole-food meals, and it did not assess long-term muscle hypertrophy or functional strength adaptations.
Cited by
- supports Consuming protein across three to four evenly spaced meals containing 25 to 30 grams or more optimizes 24-hour muscle protein synthesis.