Effects of Exercise Training Intensity on Fitness and Insulin Sensitivity in African Americans

Inclusion Criteria

• African American
• Body mass index 30-45 kg/m2
• sedentary/low active (step count ≤ 6, 500 step/day)
• capable and willing to give written informed consent and understand exclusion criteria
• willingness to accept group assignment from randomization
• No resistance training and no structured aerobic exercise for > 20 minutes per day, 3+ days per week, for the last 6 months
• conditions that are contraindicated for exercise training

Exclusion Criteria

• Resting blood pressure > 180 mm Hg systolic and/or >100 mm Hg diastolic; individuals on blood pressure medications meeting the blood pressure criteria are eligible
• Diagnosis of type 1 or 2 diabetes, and/or fasting glucose >125 mg/dL
• Medication for the treatment of type 1 or type 2 diabetes
• Bariatric surgery including gastric banding or bypass (potential effects on energy intake)
• Factors that may limit adherence to intervention or affect conduct of the trial
• Unable or unwilling to communicate with staff
• Failure to complete run-in or baseline testing
• Hospitalization for depression or severe mental illness in the last 6 months
• Not physically capable of performing the exercise required of the study protocol
• Consuming more than 14 alcoholic beverages per week
• Plan to be away from the Pitt County area more than 3 weeks in the next 3 months
• Lack support from a primary health care provider or family members
• Significant weight loss in the past year (> 20 pounds) or are currently using weight loss medications.
• Current diagnosis of schizophrenia, other psychotic disorders, or bipolar disorder
• Another member of the household who is currently a participant or staff member of this study
• Other temporary intervening event, such as sick spouse, or bereavement
• Other medical, psychiatric, or behavioral limitations that may interfere with study participation or the ability to follow the intervention protocol
• Underlying diseases or conditions likely to limit lifespan and/or affect the safety of the intervention
• Cancer requiring treatment in the past 5 years with anything but excellent prognosis
• Self-reported HIV, tuberculosis, Hepatitis B, or Hepatitis C
• History or evidence of serious arrhythmias, cardiomyopathy, congestive heart failure, aortic aneurism, myocardial infarction or heart transplantation
• Renal disease: urine protein > 100 mg/dl, serum creatinine ≥ 1.5 mg/dl or currently receiving dialysis.
• Auto-immune diseases (such as Lupus, Multiple Sclerosis, Graves' disease, or Rheumatoid arthritis)
• Chronic obstructive lung disease, peripheral vascular disease or angina that limits ability to follow exercise protocol
• History of stroke or transient ischemic attack
• History of vascular aneurysms
• History of bleeding disorders
• Pregnancy or plans to become pregnant
• Dieting or plans to diet, or in a weight loss program
• Any other medical condition or disease that is life threatening or that can interfere with or be aggravated by exercise.