Areta, J., Burke, L., Camera, D., West, D., Crawshay, S., Moore, D., Stellingwerff, T., Phillips, S., Hawley, J. A & Coffey, V. (2014). Reduced resting skeletal muscle protein synthesis is reduced by resistance exercise and protein ingestion following short-term energy deficit. American Journal of Physiology: Endocrinology and Metabolism,306(8), E989-E997. Retrieved from https://doi.org/10.1152/ajpendo.00590.2013
The myofibrillar protein synthesis (MPS) response to resistance exercise (REX) and protein ingestion during energy deficit (ED) is unknown. In young men (n = 8) and women (n = 7), we determined protein signaling and resting postabsorptive MPS during energy balance [EB; 45 kcal·kg fat-free mass (FFM)−1·day−1] and after 5 days of ED (30 kcal·kg FFM−1·day−1) as well as MPS while in ED after acute REX in the fasted state and with the ingestion of whey protein (15 and 30 g). Postabsorptive rates of MPS were 27% lower in ED than EB (P < 0.001), but REX stimulated MPS to rates equal to EB. Ingestion of 15 and 30 g of protein after REX in ED increased MPS ∼16 and ∼34% above resting EB (P < 0.02). p70 S6K Thr389 phosphorylation increased above EB only with combined exercise and protein intake (∼2–7 fold, P < 0.05). In conclusion, short-term ED reduces postabsorptive MPS; however, a bout of REX in ED restores MPS to values observed at rest in EB. The ingestion of protein after REX further increases MPS above resting EB in a dose-dependent manner. We conclude that combining REX with increased protein availability after exercise enhances rates of skeletal muscle protein synthesis during short-term ED and could in the long term preserve muscle mass.