Physical activity and weight loss: does prescribing higher physical activity goals improve outcome?

Recommending increased physical activity facilitates long-term weight loss, but the optimal level of physical activity to recommend is unknown.

The objective of the study was to evaluate the efficacy for long-term weight loss of recommendations for much higher physical activity than those normally used in behavioral treatments.

Overweight men and women (n = 202) were randomly assigned to either a standard behavior therapy (SBT) for obesity, incorporating an energy expenditure (EE) goal of 1000 kcal/wk, or to a high physical activity (HPA) treatment, in which the goal was an EE of 2500 kcal/wk. To help HPA treatment group participants achieve this high exercise goal, their treatment included encouragement to recruit 1-3 exercise partners into the study, personal counseling from an exercise coach, and small monetary incentives.

The HPA treatment group reported achieving higher mean (+/- SD) physical activity levels than did the SBT group at 6 mo (EE of 2399 +/- 1571 kcal/wk compared with 1837 +/- 1431 kcal/wk), 12 mo (EE of 2249 +/- 1751 kcal/wk compared with 1565 +/- 1309 kcal/wk), and 18 mo (EE of 2317 +/- 1854 kcal/wk compared with 1629 +/- 1483 kcal/wk) (all P < 0.01). Mean (+/- SEM) cumulative weight losses at 6, 12, and 18 mo in the HPA treatment group were 9.0 +/- 7.1, 8.5 +/- 7.9, and 6.7 +/- 8.1 kg, respectively. In the SBT group, the corresponding weight losses were 8.1 +/- 7.4, 6.1 +/- 8.8, and 4.1 +/- 7.3 kg, respectively. Between-group differences in weight loss were significant at 12 and 18 mo.

These results suggest that recommendations of higher levels of physical activity (EE of 2500 kcal/wk) promote long-term weight loss better than do conventional recommendations.