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 .
Prescribing exercise in multiple short bouts versus one continuous bout: effects on adherence, cardiorespiratory fitness, and weight loss in overweight women.
OBJECTIVE To investigate whether prescribing exercise in several short-bouts versus one long-bout per day would enhance exercise adherence , cardiorespiratory fitness , and weight loss in overweight adult females in a behavioral weight control program . DESIGN R and omized controlled trial with subjects r and omized to either a short-bout exercise group ( SB , n = 28 , age = 40.4 + /- 5.9 yrs ) or a long-bout exercise group ( LB , n = 28 , age = 40.9 + /- 7.3 yrs ) , with subjects followed for a period of 20 weeks . Both groups were instructed to exercise 5 days per week with exercise duration progressing from 20 to 40 min per day . The LB group performed one exercise bout per day , whereas the SB group performed multiple 10 min bouts of exercise per day . The recommended caloric intake for all subjects was 5022 - 6277 kJ/day ( 1200 - 1500 kcal/day ) , with fat reduced to 20 % of caloric intake . SUBJECTS Fifty-six obese , sedentary females ( BMI = 33.9 + /- 4.1 kg/m2 ) . MEASUREMENTS Exercise participation was assessed from self-reported diaries and Tri-Trac Accelerometers . Cardiorespiratory fitness was assessed using a submaximal cycle ergometer test . RESULTS Exercising in multiple short-bouts per day improved adherence to exercise : the SB group reported  exercising on a greater number of days ( mean + /- s.d . = 87.3 + /- 29.5 days vs 69.1 + /- 28.9 days ; P < 0.05 ) and for a greater total duration ( 223.8 + /- 69.5 min/week vs 188.2 + /- 58.4 min/week ; P = 0.08 ) than the LB group . Predicted VO2Peak increased by 5.6 % and 5.0 % for the LB and SB groups , respectively ( P < 0.05 ) . There was a trend for the weight loss to be greater in the SB group ( -8.9 + /- 5.3 kg ) compared to the LB group ( -6.4 + /- 4.5 kg ; P < 0.07 ) . CONCLUSION These results suggest that short-bouts of exercise may enhance exercise adherence .  Short-bouts of exercise may also enhance weight loss and produce similar changes in cardiorespiratory fitness when compared to long-bouts of exercise . Thus , short-bouts of exercise may be preferred when prescribing exercise to obese adults
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 .