Leucine Co-Ingestion Augments the Muscle Protein Synthetic Response to the Ingestion of 15 g Protein Following Resistance Exercise in Older Men

Holwerda, A.M.; Paulussen, K.J.M.; Overkamp, M.; et al.

Anabolic resistance is considered to play a key role in the progression of sarcopenia in older adults. Resistance exercise potently increases muscle protein synthesis, with post-exercise recovery further enhanced by the ingestion of >40 g of protein. Since older individuals may not be able to ingest such large doses of protein, van Loon and colleagues investigated the effect of co-ingesting 15 g of protein with or without added leucine. By combining the ingestion of an intrinsically labeled protein beverage with an infusion of stable isotope-labeled amino acids, its metabolic impact during post-exercise recovery could be evaluated. The results revealed that co-ingesting a lower amount of protein with free leucine further increases muscle protein synthesis during post-exercise recovery in older adults.