View clinical trials related to Substrate Utilization.
Filter by:Exercising in the fasted state results in greater fat oxidation during exercise and results in decreased caloric intake in the meals after exercise. However, the studies that examine fasted vs. fed exercise utilize a carbohydrate-based breakfast, which can increase blood glucose and insulin concentrations, which is considered a negative consequence. A protein breakfast, which can increase satiety and rest of day energy intake could also increase resting energy expenditure as well as fat oxidation during exercise. However, comparisons between fasting exercise and pre-exercise breakfast macronutrient intake (i.e., carbohydrate vs. protein) have not been made. Therefore the purpose of this study is to investigate if eating breakfast and the composition of this breakfast before exercise has an effect on the food eaten throughout the rest of the day.
The investigators will examine the long-term effects of a combined training and diet intervention that, acutely, increases fat oxidation during exercise. This is done with a 4 week intervention study with moderately trained cyclists. Performance is tested pre and post intervention and muscle biopsies are obtained.
Women sexual hormones (i.e. estrogen) are involved in the regulation of substrate utilization and storage. Being under oral contraception (OC) may conduct to metabolic and hormonal modifications, but results are confused regarding the impact on substrate utilization. In the present study, the aim is then to explore the effect of hormonal status on substrate utilization during sous-maximal exercise, comparing women with and without OC. We hypothesised that women under OC have a lower Respiratory Exchange Ratio (RER) at exercise than women without contraception underlying a greater reliance on fat oxidation.