ACTIV- Exercise Intervention in Healthy Young Men

Inclusion Criteria: T2DM group: * Men aged 25-35 * BMI \> 30 kg/m2 * Sedentary lifestyle determined by activity index questionnaire (not involved in regular exercise program) and accelerometer data. * Are willing to eat only foods provided by Pennington for the study period * Diagnosed with T2DM defined by one or more of the following: * fasting plasma glucose \> 126 mg/dL at entry * a two-hour OGTT glucose \> 200mg/dL * current medication for T2DM Obese group: * Men aged 25-35 * BMI \> 30 kg/m2 * Sedentary lifestyle activity index questionnaire (not involved in regular exercise program) and accelerometer data. * Are willing to eat only foods provided by Pennington for the study period FH+ group: * Men aged 25-35 * One parent diagnosed with T2DM * fasting insulin \> 10mIU/ml (\> 50th %tile) * BMI between 22 and 30 kg/m2 * Sedentary lifestyle activity index questionnaire (not involved in regular exercise program) and accelerometer data. * Are willing to exercise every day for the study period * Are willing to eat only foods provided by Pennington for the study period FH- group: * Men aged 25-35 * Parents and grandparents were not diagnosed with T2DM * Fasting insulin \< 10mIU/ml (\< 50th %tile) * BMI between 22 and 30 kg/m2 * Sedentary lifestyle activity index questionnaire (not involved in regular exercise program) and accelerometer data. * Are willing to exercise for the study period * Are willing to eat only foods provided by Pennington for the study period Athlete group: * Men aged 25-35 * Maximal oxygen uptake \> 60 ml/kg.min * Are engaged in minimum of 1.5 h of aerobic exercise 3 times/ week * Are willing to eat only foods provided by Pennington for the study period Exclusion Criteria: * Abnormal resting or exercise ECG * Significant renal, cardiac, liver, lung, or neurological disease (controlled hypertension is acceptable if baseline bp \< 140/90 on medications) * Use of drugs known to affect energy metabolism or body weight: including, but not limited to: orlistat, sibutramine, ephedrine, phenylpropanolamine, corticosterone, etc * Alcohol or other drug abuse * Smoking * Gait problems * Unwilling or unable to abstain from caffeine (48h) prior to metabolic rate measurements * Unwilling or unable to eat all study foods * Increased liver function tests at baseline (AST/ALT/GGT/or alkaline phosphatase greater than 2.5 times the upper limit of normal) * Metal objects that would interfere with the measurement of body composition /MRS such as implanted rods, surgical clips, etc * NYHA class III/IV CHF is an exclusionary cardiac condition * history of deep vein thrombosis (DVT) or pulmonary embolism (PE) * varicose veins * major surgery on the abdomen, pelvis, or lower extremities within previous 3 months * cancer (active malignancy with or without concurrent chemotherapy) * rheumatoid disease * bypass graft in limb * known genetic factor (Factor V Leiden, etc) or hypercoagulable state * diagnosed peripheral arterial or vascular disease, or intermittent claudication * family history of primary DVT or PE (pulmonary embolism) * peripheral neuropathy