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 .
Effects on glucose tolerance, insulin secretion, insulin-like growth factor 1 and its binding protein, IGFBP-1, in a randomized controlled diet and exercise study in healthy, middle-aged men.
OBJECTIVES To study the effects of advice on diet , exercise and their combination on oral glucose tolerance ( OGTT ) , insulin secretion , insulin-like growth factor-1 ( IGF-1 ) and its binding protein , IGFBP-1 . DESIGN A 6-month , r and omized , controlled intervention study . SETTING Primary health care centres in Sollentuna , Stockholm and the Department of Medicine , Karolinska Hospital , Stockholm , Sweden . SUBJECTS One hundred and fifty-seven normoglycaemic healthy men , mean age 46 years , range 35 - 60 years , with slightly to moderately raised cardiovascular risk factors . INTERVENTIONS Advice on diet ( D , n = 40 ) , exercise ( E , n = 39 ) a combination of both ( DE , n = 39 ) and a control group ( C , n = 39 ) . MAIN OUTCOME MEASURES An OGTT , insulin secretion , IGF-1 and its binding protein , IGFBP-1 . RESULTS The number of pathological OGTTs in the intervention groups decreased from 42/118 to 33/118 whilst the number in the control group did not change . Fasting insulin levels decreased in groups E and DE from 8.8 - 7.4 mU L-1 ( P < 0.01 ) and from 8.3 - 6.7 mU L-1 ( P < 0.01 ) , respectively . Accordingly , the insulin area under the curve decreased from 5278 to 4828 ( P < 0.05 ) in group E , and from 5482 to 4809 ( P < 0.01 ) in group DE . IGF-1 only increased in group D. The most prominent changes were noted for IGFBP-1 , which increased in all three intervention groups and to the highest degree in group DE ( from 33.7 - 42.6 micrograms L-1 , P < 0.001 ) . CONCLUSIONS A combination of increased exercise and improved diet , as well as increased exercise alone , favourably affect glucose and insulin homeostasis in middle-aged men with moderately elevated cardiovascular risk factors . The most marked changes were noted for IGFBP-1 , possibly suggesting a decreased insulin secretion and an enhanced insulin sensitivity
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 .