The Effect of Supervised Exercise on Physical Fitness and Energy Expenditure in Post Bariatric Surgery Patients

Inclusion Criteria: 1. RYGB or GB surgery patients who are at least 12 weeks post surgery 2. BMI of 40 or more 3. age 18-70years 4. sedentary lifestyle (energy expenditure of \<35 kcal/kg/day measured by 7-day physical activity recall and no regular moderate physical activity exceeding 20 min/day within the previous 3 months) 5. willingness to alter physical activity in accordance with the intervention programs 6. English or Spanish speaking. Exclusion Criteria: 1. body weight \> 180 kg 2. cardiovascular disease 3. pulmonary disease 4. uncontrolled hypertension (resting DBP \>100 or SBP \>180 mm of Hg) 5. visual or hearing impairment 6. functional limitations (difficulty walking one-quarter mile or climbing 10 stairs) 7. abnormal ECG on VO2max test ( \>1 mm ST segment depression at \< 5 METS or with symptoms such as atrial fibrillation, complex ventricular arrhythmias and 3rd degree atrioventricular block) 8. known liver disease due to causes other than nonalcoholic steatohepatitis (liver transaminases \> 2.5 times the upper limits of normal \[SGPT\>105 U/L, SGPT\>120 U/L\] or total bilirubin \>1.5 mg/dL) 9. hematocrit of less than 30% 10. current alcohol abuse (\>7 drinks or 210 g/wk for women and \>14 drinks or 420 g/wk for men) 11. recreational drug abuse 12. current use of any drugs capable of inducing weight loss (e.g., orlistat, sibutramine, topiramate, etc.) 13. major neuro-psychiatric illnesses impeding competence or compliance 14. pregnancy and lactation 15. chronic renal insufficiency (serum creatinine \> 2 mg/dL) 16. untreated thyroid disorders such as hypothyroidism and hyperthyroidism; and 17) bariatric surgical complications including anastomotic leak, wound complications, thrombotic disorders, intestinal obstruction, stomal complications, GI bleeding, recurrent severe abdominal pain, bilious vomiting.