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 .
The effect of office-based physician's advice on adolescent exercise behavior.
BACKGROUND This study examines whether the adolescents ' current levels of physical activity are increased by their physicians ' advice provided in the office , in accordance with the American Medical Association recommendation . METHODS The first adolescent ( 12 - 21 years old ) of whichever age and gender , passing through six family physicians ' offices during a 6-month period was assigned to the intervention group , and the second adolescent of the same age and gender was assigned to the control group .  Each patient was classified as active , partially active , and inactive , according to how they answered the questions about their physical activity levels , and patients in the intervention group were then provided with reinforcement , increase , or initiation counseling , respectively . Identical procedures were repeated at the 6- and 12-month office visits . Changes in prevalence of activity , as well as , duration , frequency , and intensity of exercise and /or sports were verified at each visit . RESULTS Of the 87.5 % of the original sample that completed the survey , 6- and 12-month data were available for 70.1 % . Among the 392 adolescents that finished the study , those provided with counseling had 41.5 % more active adolescents , as well as 26.8 % , 38.0 % and 26.2 % higher duration , frequency and intensity , respectively , than the control group . CONCLUSIONS The proportion of active adolescents , as well as , the duration , frequency and intensity of leisure time exercise and /or sports are increased by physician advice
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 .