Influence of protein nutrition and exercise on muscle metabolism.

At present, there is no clear consensus as to whether protein feeding harnesses any ergogenic benefit for endurance athletes. In this thesis demonstrate no effect of protein on endurance performance. Furthermore, data presented herein indicates that protein co-ingestion does not enhance recovery 24 hours after exercise. Consequently, there is currently no basis on which to recommend protein feeding for endurance performance and recovery. Nutrient strategies implemented after exercise can markedly alter the acute response of muscle protein synthesis and, potentially, long-term phenotypic adaptation. Protein nutrition has traditionally been considered in the context of resistance exercise. Endurance exercise followed by protein ingestion increases the synthesis of mixed muscle protein via increased mRNA translation. Herein, we demonstrate that protein feeding after endurance exercise elevates the synthetic rate of contractile proteins and specific mRNA signalling intermediates. Insulin resistance that precedes Type II diabetes is characterized by blunted sensitivity of the pancreas to glucose and impaired glucose uptake in skeletal muscle. Lifestyle interventions including nutrient and exercise have the potential to improve glycemic control. The final experimental chapter in this thesis provides mechanistic evidence to support the benefits of resistance exercise for lowering post-prandial glucose concentrations. Interestingly, protein ingestion did not augment the glucose-lowering effects of prior resistance exercise.