Time of Exercise Specifies the Impact on Muscle Metabolic Pathways and Systemic Energy Homeostasis
Shogo Sato Cell Metab 30, ISSUE 1, P92-110.E4, JULY 02, 2019
Highlights
• Distinct response of metabolic cycles in skeletal muscle to time-of-day exercise
• Early active phase exercise exerts a robust metabolic response in skeletal muscle
• The metabolic response includes glycolysis, lipid oxidation, and BCAA breakdown
• Time of exercise specifies the activation of HIF1α and systemic energy expenditure
While the timing of food intake is important, it is unclear whether the effects of exercise on energy metabolism are restricted to unique time windows. As circadian regulation is key to controlling metabolism, understanding the impact of exercise performed at different times of the day is relevant for physiology and homeostasis. Using high-throughput transcriptomic and metabolomic approaches, we identify distinct responses of metabolic oscillations that characterize exercise in either the early rest phase or the early active phase in mice. Notably, glycolytic activation is specific to exercise at the active phase. At the molecular level, HIF1α, a central regulator of glycolysis during hypoxia, is selectively activated in a time-dependent manner upon exercise, resulting in carbohydrate exhaustion, usage of alternative energy sources, and adaptation of systemic energy expenditure. Our findings demonstrate that the time of day is a critical factor to amplify the beneficial impact of exercise on both metabolic pathways within skeletal muscle and systemic energy homeostasis.
