CONTEXT

Enhancing participation in long-term exercise may translate into improved long-term weight loss in overweight adults.

OBJECTIVES

To compare the effects of intermittent with traditional continuous exercise on weight loss, adherence, and fitness, and to examine the effect of combining intermittent exercise with that using home exercise equipment.

DESIGN

Randomized trial from September 1996 through September 1998.

SETTING AND PARTICIPANTS

A total of 148 sedentary, overweight (mean [SD] body mass index, 32.8 [4.0] kg/m2) women (mean [SD] age, 36.7 [5.6] years) in a university-based weight control program.

INTERVENTIONS

Eighteen-month behavioral weight control program with 3 groups: long-bout exercise (LB), multiple short-bout exercise (SB), or multiple short-bout exercise with home exercise equipment (SBEQ) using a treadmill.

MAIN OUTCOME MEASURES

Body weight, body composition, cardiorespiratory fitness, and exercise adherence.

RESULTS

Of 148 subjects, 115 (78%) completed the 18-month program. At 18 months, mean (SD) weight loss was significantly greater in subjects in the SBEQ group compared with subjects in the SB group (-7.4 [7.8] kg vs -3.7 [6.6] kg; P<.05). Mean (SD) weight loss for subjects in the LB group (-5.8 [7.1] kg) was not significantly different than for subjects in the SB or SBEQ groups. Subjects in the SBEQ group maintained a higher level of exercise than subjects in both the SB and LB groups (P<.05) at 13 to 18 months of treatment. All groups showed an increase in cardiorespiratory fitness from baseline to 18 months, with no difference between groups. Mean (SD) weight loss at 18 months was significantly greater in individuals exercising more than 200 min/wk throughout the intervention (-13.1 [8.0] kg) compared with individuals exercising 150 to 200 min/wk (-8.5 [5.8] kg) or less than 150 min/wk (-3.5 [6.5] kg) (P<.05).

CONCLUSIONS

Compared with the LB group, subjects in the SB group did not experience improved long-term weight loss, exercise participation, or cardiorespiratory fitness. Access to home exercise equipment facilitated the maintenance of SB, which may improve long-term weight loss. A dose-response relationship exists between amount of exercise and long-term weight loss in overweight adult women.