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 .
An Occupation Based Physical Activity Intervention Program
The purpose of this quasi-experimental study was to determine the effectiveness of an occupation based health and fitness program .  Subjects were 1,504 police trainees ( 85 % male , 15 % female ) with an ethnic distribution of 82 % white , 16 % African American , and 2 % other . Data were collected at 25 sites across the state of North Carolina . The sites were r and omly assigned to either the experimental group ( implemented the intervention ) or the control group ( continued usual training ) . As compared with controls , subjects at the experimental sites improved significantly in cardiovascular fitness ( aerobic power ) , general muscular strength ( number of sit ups per minute ) , and flexibility , and lowered their body fat . The intervention required minimal equipment and was taught primarily by peers who received a 1 week training program . This occupational approach to improving health could be particularly useful in occupations with many workers who seldom engage in leisure time 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 .