The purpose of this study was to investigate effects of the ropeless-skipping exercise for prevention and improvement of obese middle school students and to provide the basic information of the effective exercise program for physical strength and growth improvement. Twenty-one obese middle school students were randomly assigned t three groups: EG1(Rope-skipping exercise group, n=7), EG2(Ropeless-skipping exercise group, n=7), CG(Control group, n=7) and the ropeless-skipping exercise have been operated for 10 weeks(45∼70% of HRR, 3days/week, 45mins/day). Paired t-test and ANCOVA were performed to analyze the difference among groups. Significance was set at a value of α<.05. The results were as follows. First, the rope-skipping exercise group and the ropeless-skipping group showed significant decrease in percent body fat (p<.05)and significant increases in left(p<.05) and right hand grip strength(p<.01), muscle endurance(p<.01), flexibility(p<.01) and cardiopulmonary endurance(p<.05) and significant differences have been shown in lean body mass(p<.01), left(p<.05) and right hand grip strength(p<.001), muscle endurance(p<.01), and cardio pulmonary endurance(p<.001) among three groups. Second, insulin resistance has decreased significantly in both the rope-skipping exercise group(p<.01) and the ropeless-skipping exercise group(p<.05) and leptin has decreased significantly in the ropeless-skipping exercise group(p<.05) and insulin resistance(p<.01) has significant difference
between the rope-skipping exercise group and the control group. In the conclusion, the ropeless-skipping exercise is effective for obese middle school students by increasing lean body mass and decreasing of Insulin-resistance and leptin levels.