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 .
Randomised controlled trial to examine the effects of a GP exercise referral programme in Hailsham, East Sussex, on modifiable coronary heart disease risk factors.
OBJECTIVE : To examine the effects of a GP exercise referral programme on modifiable  coronary heart disease risk factors . DESIGN : R and omised controlled trial . A battery of vali date d measures were carried out at 0 , 8 , 16 , 26 , and 37 weeks . SETTING : Two community health centres and a leisure centre in Hailsham , East Sussex . SUBJECTS : 389 patients ( smokers , hypertensive or overweight ) were selected from medical records , screened for contraindications to exercise and 345 were invited into the study . Of 142 patients r and omly allocated , 40 ( 41 % ) completed the study in the exercise group and 31 ( 69 % ) in the control group .  Sixty ( 35 % ) invited smokers ( 48 % of non-smokers ) , 71 ( 38 % ) invited hypertensive patients ( 45 % of non-hypertensive patients ) , and 107 ( 45 % ) overweight patients ( 33 % of non-overweight patients ) were r and omised . Of those r and omised , 27 ( 45 % ) smokers , 52 ( 48 % ) overweight , and 43 ( 61 % ) hypertensive patients completed the study . INTERVENTION : The exercise group was offered 20 , half price sessions over 10 weeks at a leisure centre . Patients engaged in moderate and vigorous aerobic type activity on various exercise machines , in a semi-supervised , informal environment . RESULTS : 87 % of those referred used the prescription and 28 % ( high adherers)(45 % of obese patients ) did at least 15 sessions . The exercise group reduced sum of skinfolds by 8.1 % ( 2.9 to 13.3 , 95 % confidence intervals ) more than the control group , up to 16 weeks after baseline . High adherers reduced sum of skinfolds by 9.2 % ( 0.9 to 17.5 ) more than the control group , up to 26 weeks . High adherers reduced systolic blood pressure by 7.2 % ( -0.7 to 14.9 ) ( that is , 9 mm Hg ) more than low adherers , up to 37 weeks . Non-smokers and obese patients attended more prescribed sessions than smokers and non-overweight patients . CONCLUSIONS : Reduction in sum of skinfolds was maintained up to 26 weeks , among high adherers compared with controls . Reduction in systolic blood pressure was evident up to 37 weeks among high adherers , but only in comparison with low adherers . Selection of appropriate referees and use of other strategies to improve exercise adherence will help to maximise the benefits from GP exercise prescription schemes
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 .