Low exercise capacity and high obesity levels are the main characteristics of people with serious mental illness (SMI). We conducted a pilot study on the effects of a 3-month exercise and dietary intervention on the aerobic capacity and body composition of obese adults with SMI taking Olanzapine, a second generation antipsychotic medication known to induce weight increments. Fifty adults with SMI (15 males and 35 females) followed a 3-month weight loss intervention programme based on exercise and diet. Pre- and post-intervention, a submaximal [Formula: see text]O2 exercise test was performed in order to assess [Formula: see text]O2max anthropometric and body composition measurements were also performed. All participants were obese (body mass index (BMI): 33.61 ± 0.91 kg/m(2)). Pre- and post-intervention, a submaximal [Formula: see text]O2 exercise test on the treadmill was performed in order to assess [Formula: see text]O2max anthropometric and body composition measurements were also performed. Significant reductions in body weight, BMI, body fat and waist circumference were found from pre to post (p < 0.01). [Formula: see text]O2max was significantly improved in both genders (males: pre: 30.63 ± 2.06 vs. post: 33.19 ± 1.77 ml(.)kg(-1) min(-1), females: pre: 25.93 ± 1.01 vs. post: 29.51 ± 1.06 ml(.)kg(-1) min(-1), p < 0.01). A significant correlation was found between the change in [Formula: see text]O2max and the change in body weight and BMI (p < 0.05). Multiple regression analysis revealed that the relative change in [Formula: see text]O2max explained approximately 26% of the variance in the changes for both BMI (p = 0.07) and body weight (p = 0.06). A treatment of exercise and diet improves the aerobic capacity and body composition of obese adults with SMI, despite the use of Olanzapine.
Keywords: Exercise; mentally ill adults; nutrition; obesity.