Abstract 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 distributions of protein feeding during
12 h recovery after resistance exercise affects anabolic responses in skeletal muscle. Twenty-four
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 in one
of the following protocols: 8×10 g every 1.5 h (PULSE); 4×20 g every 3 h (intermediate: INT);
or 2×40 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 skeletalmuscle and has the potential to maximize outcomes of resistance training for attaining
peak muscle mass.
http://www.ncbi.nlm.nih.gov/pubmed/23459753
