The purpose of this study was to test the hypothesis that a low impact aerobic dance is a useful exercise mode for weight loss in obese middle-aged women. Sixty Japanese women, aged 50.9 +/- 6.7 years (initial %fat = 35.2 +/- 5.3%), participated in our 3-month weight-loss program consisting of diet and exercise prescription. To compare the effectiveness of exercise modes, the subjects were divided into the following two groups: aerobic dance group and jogging and/or cycling group. As a result, body mass (-3.1 and -3.3 kg respectively) and %fat (-6.1 and -5.3% respectively) significantly decreased (P < 0.05) in both groups, while fat-free mass remained essentially unchanged. Aerobic power such as maximal oxygen uptake and oxygen uptake corresponding to lactate threshold significantly increased (P < 0.05) in both groups. Significant difference in the alterations in these variables between groups could not be seen. The data of this study indicates that our weight-loss program with a low impact aerobic dance is as useful as jogging or cycling in improving body composition and aerobic power for mildly obese middle-aged women.