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 .
Recruitment of older adults for a randomized, controlled trial of exercise advice in a general practice setting.
OBJECTIVES The success of any clinical trial depends strongly on recruiting enough participants in a reasonable time period . This paper aims to identify the obstacles , as well as the successful aspects , of recruiting of older participants into an exercise study . DESIGN This describes the recruitment of 299 older adults into a r and omized , controlled trial of exercise advice in a general practice setting . Letters of invitation were sent from two general practice s inviting the patients to attend a 15-minute screening appointment . Patients considered eligible for enrollment were then scheduled for a baseline appointment and r and omized into the trial . SETTING Two general practice s in Adelaide , South Australia . PARTICIPANTS Healthy , sedentary , community-dwelling patients aged 60 years or older . RESULTS A total of 2878 letters of invitation were sent , and 913 patients attended a screening appointment . Of these , 351 ( 38.4 % ) were initially eligible , with one-third excluded because they were already too physically active . Two hundred ninety-nine participants , approximately 1 of every 10 patients sent letters , were enrolled in the project at the end of a 15-week period . DISCUSSION A general practice approach was effective in recruiting 299 older adults  to an  exercise project  within an acceptable time frame . Factors promoting the success of recruitment through general practice included choosing large , well established practice s , computerized age-sex registers , and placing minimal dem and s on the general practitioners and practice staff . A continuing problem with recruiting participants for a project involving exercise is that the volunteer population tends to be healthy and interested in physical activity
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 .