Whey Protein Support to Metabolic and Performance Adaptations in Response HIIT

High intensity interval training (HIIT) has recently emerged as a time efficient alternative to conventional endurance exercise, conferring similar or superior benefits in terms of metabolic and performance adaptations in both athletic and non-athletic populations. Some of these physiological adaptations include augmented mitochondrial biogenesis and improved substrate metabolism in peripheral tissues such as skeletal muscle. However, nutritional strategies to optimise the adaptations to HIIT have yet to be established. Recent evidence suggests that acute nutritional status can affect the molecular regulation of genes mediating substrate metabolism and mitochondrial biogenesis. Moreover, preliminary evidence suggests that completion of exercise in fasted conditions augments some of these exercise-induced adaptations compared with the fed state. Given the fact that the transient molecular adaptations to acute exercise mediate long-term physiological adaptations, an investigation into the effects of different nutritional interventions on metabolic and performance responses to HIIT is warranted. The purpose of this study is to determine the effects of fasted vs. fed-state (Whey Protein) HIIT on metabolic and performance adaptations in the acute (single exercise session) and chronic (3 weeks, 9 exercise sessions) phases. The primary hypothesis is that different pre-exercise feeding conditions (e.g. fasted placebo vs. Whey protein fed) will result in divergent physiological adaptations in terms of skeletal muscle metabolism and performance, both in response to a single HIIT session and a chronic HIIT intervention.