Holwerda, A. M., Kouw, I. W., Trommelen, J., Halson, S. L., Wodzig, W. K., Verdijk, L. B., & van Loon, L. J. (2016). Exercise enhances the overnight muscle protein synthetic response to pre-sleep protein feeding in older males. Medicine & Science in Sports & Exercise, 48(5), Supplement abstract number 85.

"The age-related decline in skeletal muscle mass is, at least partly, attributed to anabolic resistance to food intake. To compensate for anabolic resistance, we recently introduced the ingestion of dietary protein prior to sleep as a nutritional strategy to increase overnight muscle protein synthesis rates."

This study assess if resistance-type exercise performed in the evening can further augment the overnight muscle-protein synthetic response to pre-sleep protein ingestion in older males. Healthy older men (~71 years) were randomly assigned to ingest 40 g casein protein before going to sleep with (protein plus exercise: N = 11) or without (protein only: N = 12) performing resistance-type exercise earlier that evening. Overnight protein digestion and absorption kinetics, whole body protein metabolism and muscle myofibrillar protein synthesis rates were assessed using primed, continuous infusions of L-[ring-2H5]-phenylalanine and L-[ring-2H2]-tyrosine with the ingestion of intrinsically L-[1-13C]-phenylalanine labeled casein protein.

Exogenous phenylalanine appearance rates expressed over time did not differ between treatments. Myofibrillar protein synthesis rates were 31% higher during overnight sleep when exercise was performed earlier that day. As well, 27% more L-[1-13C]-phenylalanine was incorporated into myofibrillar protein in the protein plus exercise group compared to the protein only group.

Implication. "Resistance-type exercise augments the overnight muscle protein synthetic response to pre-sleep protein ingestion and allows more of the ingested protein to be directed towards de novo muscle protein synthesis during overnight sleep in older males."

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