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 .
Exercise and the transtheoretical model: a longitudinal test of a population sample.
BACKGROUND The purpose of this study was to test the ability of the Transtheoretical Model ( TTM ) to predict exercise stage transition of individuals in a large , untreated- population -based , r and om sample of Canadian adults ( 18 - 65 years of age ) over two consecutive time periods . METHODS Assessment s of TTM 's  stage of exercise behavior change , self-efficacy , pros , cons , experiential processes , and behavioral processes were made at baseline ( time 1 ) , 6 months ( time 2 ) , and 1 year ( time 3 ) . Six hundred eighty-three men and women , identified through r and om-digit telephone dialing , completed all measures across the three time points . Within each time period ( time 1 - 2 ; time 2 - 3 ) participants were categorized as having regressed ( moved back at least on stage ) , remained ( no stage change ) , or progressed ( moved forward at least one stage ) . Baseline TTM constructs were analyzed for their ability to predict change transition across the two time periods . RESULTS Of 40 possible predictions ( 20 for each time period ) 18 ( 45 % ) were supported . CONCLUSIONS Overall , the findings demonstrate partial support for the internal validation of TTM in the exercise domain . Implication s of the findings are discussed and future directions for research ers , practitioners , and program planners are provided
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 .