Psychological and perceived situational predictors of physical activity: a cross-sectional analysis.

The purpose of this study was to identify psychological and self-reported situational factors that are associated with degree of involvement in moderate-intensity physical activity at various stages of adult life. The study is grounded in Personal Investment Theory which proposes that personal incentives, sense of self and perceived options determine behavior. Participants aged 18 and above, selected by random-digit dialling, were invited to participate in a study on physical activity habits. Of 251 who agreed to participate, 41.4% were male (N = 104) and 58.6% were female (N = 147). These participants were asked the number of days per week that they engaged in physical activity which accumulated a total of 30 min or more. The 140 participants who indicated one or more days of activity answered questions concerning personal incentives for physical activity, sense of self and perceived barriers. Stepwise multiple regression analyses and discriminant function analysis indicated that Personal Investment Theory is able to predict up to 29% of the variance associated with voluntary participation in moderate-intensity physical activity. Discussion focuses on implications for physical activity programs for citizens at different stages of their adult life.