Participants will be randomized into one of two different experimental groups: 1) Exercise group and 2) No exercise (control group). Subject participation in the study will involve a series of metabolic tests before and after participants undergo a 10% weight loss program (with or without exercise training depending on group randomization). After completing this weight loss portion of the study, participants will then be required to adhere to a high calorie diet program to regain half of the weight the participant lost - followed by the same series of metabolic tests.