Timing and distribution of protein ingestion during prolonged recovery from resistance exercise alters myofibrillar protein synthesis.
J Physiol. 2013 Mar 4. [Epub ahead of print] Areta JL, Burke
Quantity and timing of protein ingestion are major factors regulating myofibrillar protein synthesis (MPS). However, the effect of specific ingestion patterns on MPS throughout a 12 h period is unknown. We determined how different distribution of protein feeding during 12 h recovery after resistance exercise affects anabolic responses in skeletal muscle.
24 healthy trained males were assigned to three groups (n=8/group) and undertook a bout of resistance exercise followed by ingestion of 80 g of whey protein throughout 12 h recovery as either:
8x10 g every 1.5 h (PULSE);
4x20 g every 3 h (intermediate: INT); or
2x40 g every 6 h (BOLUS).
Muscle biopsies were obtained at rest and after 1, 4, 6, 7 and 12 h post-exercise. Resting and post-exercise MPS (L-[ring-13C6] phenylalanine), and muscle mRNA abundance and cell signalling were assessed. All ingestion protocols increased MPS above rest throughout 1-12 h recovery (88-148%, P<0.02), but
INT elicited greater MPS than PULSE and BOLUS (31-48%, P<0.02).
In general signalling showed a BOLUS>INT>PULSE hierarchy in magnitude of phosphorylation. MuRF-1 and SLC38A2 mRNA were differentially expressed with BOLUS.
In conclusion, 20 g of whey protein consumed every 3 h was superior to either PULSE or BOLUS feeding patterns for stimulating MPS throughout the day. This study provides novel information on the effect of modulating the distribution of protein intake on anabolic responses in skeletal muscle and has potential to maximise outcomes of resistance training for attaining peak muscle mass.
