Relationships between obesity, functional exercise capacity, physical activity participation and physical self-perception in people with schizophrenia

Objective: This study compared differences in functional exercise capacity between patients with schizophrenia and healthy controls. Physical self-perception and physical activity variables contributing to the variability in the distance achieved during a walk test were identified. Method: A total of 25 normal weight, 25 overweight and 10 obese patients and 40 healthy volunteers were included. Functional exercise capacity was explored with a 6-minute walk test. Level of physical activity was assessed using the Baecke questionnaire and physical self-perception using the physical self-perception profile. Results: Obese patients walked a significantly shorter distance than overweight and normal weight patients (450.6 +/- 97.7, 580.2 +/- 116.0 and 615.8 +/- 92.4 m resp., P < 0.001). All patients walked a shorter distance than healthy controls (710.6 +/- 108.4 m, P < 0.001). Dyspnoea was only prevalent in schizophrenia (28.3%, P < 0.001) and especially in obese patients (90% vs. 40% in overweight and 27.3% in normal weight patients, P < 0.001). In multiple regression analysis, 59% of the variance in walking distance was explained by body mass index, perceived sports competence and condition, physical self-worth, level of sports participation and smoking behaviour. Conclusion: Functional exercise capacity in patients with schizophrenia is reduced not only by obesity, perceived discomfort and pain but also by a sedentary, unhealthy life style and a reduced physical self-perception.