Morton RW, et al. - This trial was initiated in order to examine if dietary protein supplementation augmented resistance exercise training (RET)-induced gains in muscle mass and strength. A substantial enhancement was yielded in the changes in muscle strength and size during prolonged RET due to dietary protein supplementation among healthy adults. A reduction was illustrated in the efficacy of protein supplementation during RET via increasing age. In contrast, training experience increased the efficacy of protein supplementation. Ingestion of protein at amounts greater than ∼1.6 g/kg/day did not additionally contribute to RET-induced gains in fat-free mass (FFM).