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.
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AI-rewrites the medical criteria so a patient or caregiver can understand them. Always confirm with the trial site.
Change in energy expenditure
Timeframe: immediately pre-breakfast, immediately post-breakfast, immediately pre-exercise, and immediately post-exercise
Change in lunch energy intake
Timeframe: 60 min post-exercise
Change in dinner energy intake
Timeframe: Day 1 (trial 1); between Days 6 and 8 (trial 2); between Days 11 and 15 (trial 3); and between Days 16 and 22 (trial 4)
Change in appetite
Timeframe: immediately pre-breakfast, immediately post-breakfast, immediately post-exercise, and immediately pre-lunch
Change in blood glucose
Timeframe: immediately pre-breakfast, immediately post-breakfast, immediately post-exercise, immediately pre-lunch, and immediately pre-dinner
Change in subjective hunger
Timeframe: baseline, immediately pre-breakfast, immediately post-breakfast, immediately post-exercise, immediately pre-lunch, immediately post-lunch, immediately pre-dinner, and immediately post-dinner