Metabolic Flexibility as a Biomarker of Adaptation to Diet and Exercise Challenges

While in the calorimeter, each subject will complete four bouts of exercise. Each bout is approximately 5 minutes in duration at a predetermined speed and elevation to achieve an intensity of 85% of VO2 max according to their fitness level test described previously. Subjects then sit quietly until either the next meal or the next exercise bout.

While in the calorimeter, each subject completes one exercise bout approximately 40 minutes in duration, at a predetermined speed and elevation, to achieve an intensity of 65% of VO2 max. Subjects then sit quietly until the next meal.

Participants will consume a high carbohydrate beverage (750 g) with the following composition: 2.13 MJ/d, 113g carbohydrate, 4g fat, 6g protein.

Participants will consume a high fat beverage (750 g) with the following composition: 2.11 MJ/d, 8g carbohydrate, 50g fat, 7g protein.