Serious mental illness (SMI) is a leading cause of worldwide disability and is associated with impaired community functioning and increased rates of medical comorbidity and mortality. People with SMI have a lifespan that is 10-12 years shorter than the general population and have high rates of obesity, sedentary lifestyle, poor dietary habits and inadequate preventive health care. Findings from a pilot study conducted by our group evaluating a novel program, """"""""In Shape Lifestyles"""""""" (ISL), suggest that significant health benefits can be achieved by persons with SMI through a health promotion program consisting of a personal fitness assessment, diet and exercise programs supported by weekly meetings with a health mentor, nurse facilitated preventive care, access to fitness facilities through a YMCA membership, dietary education and consultation, an incentive program, and group motivational sessions. The ISL intervention is guided by the ICF Model of Functioning, Disability, and Health by addressing mental and physical functioning and impairments, activity limitations and participation restrictions, environmental factors, and personal factors. In the proposed randomized, controlled study, 130 adults age 21+ with SMI and poor physical fitness (BMI > 25, or < 10 minutes of exercise 2x over the past month) will be randomized to either: a) ISL or b) Health Club Membership and Education (HOME): consisting of a YMCA membership, educational materials on exercise and healthy diet, and an on-site introduction to the health club. The following three specific aims will be addressed: (1) To compare ISL and HCME with respect to: (a) participation in regular exercise and dietary change; (b) participation in preventive health care; and (c) improved fitness and health; (2) to compare ISL and HCME with respect to: (a) indicators of mental health and (b) personal self-efficacy; and (3) to explore differences in ISL and HCME with respect to (a) selected physical, metabolic, dietary, and community functioning secondary outcomes; and (b) the relationship of demographic variables and readiness to change to outcomes. ISL participants will receive a six-month intensive program of one-to-one health mentoring, followed by a 3-month period of transitioning to self-directed individual and group programming, with assessments conducted at baseline, 3, 6, 9 and 12 months. If found to be effective, ISL will provide a practical approach to improving health, independent functioning, and longevity in disabled persons with SMI. ? ? ?