Men and women, aged 28-55 year-old, in general good health and with no contraindications to exercise. We are recruiting three groups of subjects: Group 1: overweight/obese adults with type 2 diabetes, with a BMI between 28-40. Group 2: overweight/obese adults without type 2 diabetes, with a BMI between 28-40. Group 3: adults without type 2 diabetes, with a BMI equal or less than 25 (not overweight/obese.)