Psychosocial Predictors of Changes in Physical Activity in Overweight Sedentary Adults Following Counseling in Primary Care

Background. Increasing regular physical activity in adults at elevated risk of cardiovascular disease is an important target for preventive medicine. This study evaluated demographic, social and cognitive predictors of self-reported changes in physical activity after 4 and 12 months in a randomized trial of behavioral counseling in primary care. Method. Data were analyzed from 234 male and 271 female sedentary patients with a body mass index of 25–35 (age 49.1 years, SD 11.2 years), who had been counseled by nurses in general practice using stage-matched behavioral methods or standard health promotion and who were reassessed after 4 months. A total of 187 men and 231 women were reassessed after 12 months. Results. Physical activity at baseline was associated with educational status, having a partner who exercised, perceived barriers, and self-efficacy. Changes over 4 months were greater with behavioral counseling, in non-smokers and in patients with higher ratings of motivation to change and self-efficacy at baseline. Changes over 12 months were greater with behavioral counseling and were predicted in the behavioral group by social support variables, perceived benefits, and barriers. Stage of readiness to change predicted increased activity at 4 but not 12 months. Conclusions. Social support and cognitive variables predict increased physical activity following counseling in primary care of sedentary overweight adults. Different factors are relevant to short- and long-term modifications in behavior.