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 .
Can lay-led walking programmes increase physical activity in middle aged adults? A randomised controlled trial
Study objective : To compare health walks , a community based lay-led walking scheme versus advice only on physical activity  and cardiovascular health status in middle aged adults . Design : R and omised controlled trial with one year follow up . Physical activity was measured by question naire . Other measures included attitudes to exercise , body mass index , cholesterol , aerobic capacity , and blood pressure . Setting : Primary care and community . Participants : 260 men and women aged 40–70 years , taking less than 120 minutes of moderate intensity activity per week . Main results : Seventy three per cent of people completed the trial . Of these , the proportion increasing their activity above 120 minutes of moderate intensity activity per week was 22.6 % in the advice only and 35.7 % in the health walks group at 12 months ( between group difference = 13 % ( 95 % CI 0.003 % to 25.9 % ) p=0.05 ) . Intention to treat analysis , using the last known value for missing cases , demonstrated smaller differences between the groups ( between group difference = 6 % ( 95 % CI −5 % to 16.4 % ) ) with the trend in favour of health walks . There were improvements in the total time spent and number of occasions of moderate intensity activity , and aerobic capacity , but no statistically significant differences between the groups . Other cardiovascular risk factors remained unchanged . Conclusions : There were no significant between group differences in self reported physical activity at 12 month follow up when the analysis was by intention to treat . In people who completed the trial , health walks was more effective than giving advice only in increasing moderate intensity activity above 120 minutes per week
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 .