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 .
Increased exercise level and plasma lipoprotein concentrations: a one-year, randomized, controlled study in sedentary, middle-aged men.
Eighty-one sedentary but healthy men aged 30 - 55 participated in a 1 yr r and omized study of the effects of exercise on  plasma lipoprotein concentrations . Forty-eight were assigned to a running program , while 33 remained as sedentary controls ( an approximately 3:2 ratio ) . After 1 yr the running group had become significantly fitter and leaner than the control group . Lipoprotein concentration changes in the runners ( vs. controls ) uniformly favored reduced risk of coronary heart disease , but were not significant when all 46 participants with complete data were included . However , the 25 men who averaged at least eight miles ( 12.9 kilometers ) per wk of running increased their plasma high-density-lipoprotein ( HDL ) cholesterol level by 4.4 mg/dl ( p = 0.045 ) and their HDL2 mass level by 33 mg/dl ( p = 0.059 ) , vs. controls . Significant correlations were found for distance run per wk vs. change in plasma HDL-cholesterol ( r = 0.48 ) , HDL2 ( r = 0.41 ) , and low-density-lipoprotein cholesterol ( r = -0.31 ) . Changes in percent body fat and in HDL-cholesterol were correlated ( r = -0.47 ) in runners . There appears to be a threshold at about 8 miles per wk above which a 1-yr running program leads to beneficial lipoprotein changes
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 .