The heterogeneity in reported effects was reduced in higher quality studies , when physical activity was self-directed with some professional guidance and when there was on-going professional support .
Our review suggests that physical activity interventions have a moderate effect on self reported physical activity and cardio-respiratory fitness , but not on achieving a predetermined level of physical activity .
Due to the clinical and statistical heterogeneity of the studies , only limited conclusions can be drawn about the effectiveness of individual components of the interventions .
BACKGROUND Little is known about the effectiveness of strategies to enable people to achieve an increase in their physical activity .
OBJECTIVES To assess the effects of interventions for promoting physical activity in adults aged 16 years and older , not living in an institution .
Evaluation of relapse prevention and reinforcement interventions to promote exercise adherence in sedentary females.
An experimental design was employed to assess the effectiveness of a relapse prevention program , a reinforcement program , and an exercise-only control group in increasing  exercise program adherence and short-term maintenance in 120 previously sedentary female university employees . The subjects participated in an 18-week exercise program composed of stretching , calisthenics , and aerobic dance .  Attendance during the first half of the program was significantly higher for subjects in the relapse prevention group than for those in the control group . A nonsignificant trend in this direction emerged during the second half of the program and at 2-month follow-up . For all treatment groups , attrition ( attendance at less than two thirds of the exercise sessions ) was substantial , averaging 72 % at the end of the 18-week program . These findings indicate that relapse prevention and reinforcement programs may not assist previously sedentary females in long-term adherence to an exercise program
The heterogeneity in reported effects was reduced in higher quality studies , when physical activity was self-directed with some professional guidance and when there was on-going professional support .
Our review suggests that physical activity interventions have a moderate effect on self reported physical activity and cardio-respiratory fitness , but not on achieving a predetermined level of physical activity .
Due to the clinical and statistical heterogeneity of the studies , only limited conclusions can be drawn about the effectiveness of individual components of the interventions .
BACKGROUND Little is known about the effectiveness of strategies to enable people to achieve an increase in their physical activity .
OBJECTIVES To assess the effects of interventions for promoting physical activity in adults aged 16 years and older , not living in an institution .