Running Title: Exercise Capacity in Overweight and Obese Individuals (47 characters)

OBJECTIVE -We examined associations of cardiovascular, metabolic, and body composition measures with exercise capacity using baseline data from 5145 overweight and/or obese (BMI > 25.0) men and women with type 2 diabetes (T2DM) who were randomized participants for the Look AHEAD clinical trial. RESEARCH DESIGN AND METHODS -Peak exercise capacity expressed as metabolic equivalents (METs) and estimated from treadmill speed and grade was measured during a graded exercise test (GXT) that was designed to elicit a maximal effort. Other measures included: waist circumference, BMI, T2DM duration, types of medication used, HbA1c, history of cardiovascular disease, metabolic syndrome, beta blockers use, race/ethnicity. RESULTS -Peak exercise capacity was higher for males (8.0 ± 2.1 METs) compared to females (6.7 ± 1.7 METs) (p<0.001). Exercise capacity also decreased across each decade of age (p<0.001) as well as with increasing BMI and waist circumference levels in both genders. Older age, increased waist circumference and BMI, a longer duration of diabetes, increased HbA1c, a history of CVD, having metabolic syndrome, beta blocker use, and being African American compared to white, were associated with a lower peak exercise capacity for both genders. Hypertension and use of diabetic medications were associated with lower peak exercise capacity in females. CONCLUSIONS -Among persons with diabetes who are overweight or obese have impaired exercise capacity, which is primarily related to: age, female sex, and race as well as poor metabolic control, BMI, and central obesity.