6-week, single site, two parallel arm, randomized, controlled trial comparing the effectiveness of a High Intensity Interval Training (HIIT) versus a continuous Moderate Intensity Training (MIT) program on cardiovascular and metabolic health outcomes in overweight adolescent males. HIIT training may be a potent time-efficient strategy to induce similar metabolic and cardiovascular adaptations typically associated with MIT.

Inclusion Criteria:

• Ages 17-22
• Men
• BMI (25.0 - 35.0 kg/m2)
• Interested in improving health and fitness

Exclusion Criteria:

• Weight loss or gain of >10% of body weight in the past 6 months for any reason.
• Currently taking medication that suppresses or stimulates appetite.
• History of prior surgical procedure for weight control or liposuction.
• Current smoker.

Any major disease, including:

• Active cancer or cancer requiring treatment in the past 2 years (except nonmelanoma skin cancer).

• Active or chronic infections, including self-reported HIV positivity and active tuberculosis.

• Diagnosed heart conditions.

• Uncontrolled hypertension: systolic blood pressure 160 mm Hg or diastolic blood pressure 95 mm Hg on treatment.

• Gastrointestinal disease, including self-reported chronic hepatitis or cirrhosis, any episode of alcoholic hepatitis or alcoholic pancreatitis within past year, inflammatory bowel disease requiring treatment in the past year, recent or significant abdominal surgery (e.g., gastrectomy).

• Asthma.

• Diagnosed diabetes (type 1 or 2), fasting impaired glucose tolerance (blood glucose 118 mg/dL), or use of any anti-diabetic medications.

  • Conditions or behaviors likely to effect the conduct of the trial: unable or unwilling to give informed consent; unable to communicate with the pertinent clinic staff; unwilling to accept treatment assignment by randomization; current or anticipated participation in another intervention research project that would interfere with the intervention offered in the trial; likely to move away from participating clinics before trial completed; unable to walk 0.25 mile in 10 minutes.
  • Currently taking antidepressant, steroid, or thyroid medication, unless dosage is stable (no change for 6 months).
  • Any active use of illegal or illicit drugs.
  • Excessive alcohol intake defined as an average consumption of 3 or more alcohol containing beverages daily.
  • Unwilling to limit alcohol intake to ≤2 drink per day (one drink = 4 oz. wine, 12 oz. beer, or ½ shot of liquor).
  • Current exerciser (>30 min organized exercise per week).
  • Indication of unsuitability of current health for exercise protocol (PARQ).
  • Any other conditions which, in opinion of the investigators, would adversely affect the conduct of the trial.