The Effects of Aerobic and Resistance Exercise on Body Composition and Biochemical Bone Markers of Elementary Male Students

PURPOSE: This study was to investigate the effects of aerobic exercise and resistance exercise on the body composition and biochemical bone markers. METHODS: Subjects for this study were forty two elementary male students and divided into 3 groups: aerobic exercise(running) group(n=14, AG), resistance exercise(dumbbell) group(n=14, RG), and control group(n=14, CG). The aerobic exercise group performed running 40 min in a bout, four times a week at the intensity of 50∼60%HRmax(1∼5 weeks; 50∼60%HRmax, 6∼10 weeks; 61∼70%HRmax). The resistance exercise group performed dumbbell exercise consisting of 12 factors using 1∼2kg weight(1∼5 weeks; 1kg, 6∼10 weeks; 2kg). And the change of body composition such as height, weight, obesity, %fat and biochemical bone makers such as osteocalcin(OC), N-telopeptide(NTx) have been measured before, by post exercise 10 weeks respectively. Data analysis were ANCOVA to determine the difference between exercise duration and the difference between the AG and the RG. RESULTS: 1. The change of body composition such as body weight(0.13kg, P < 0.1; 0.87kg, P < .01), obesity(2.57%, P < .01; 1.85%, P < .01), and % fat(4.01%, P < .01; 4.17%, P < .01) in the AG and the RG were decreased significantly after 10 weeks of exercise. And there was significant difference between the two exercise groups in body weight but there is no significant difference between the groups in obesity and %fat. Also height(1.24cm, P < .01; 1.97cm, P < .01) was increased significantly after 10 weeks, and there was no significant difference between the two exercise groups. 2. The change of biochemical bone makers(OC, NTx) in the AG and the RG were increased significantly after exercise 10 weeks. That is, biochemical bone markers such as OC(9.16ng/ml, P < .01; 13.78ng/ml, P < .01) and NTx(330.57ng/ml, P < .01; 183.07ng/ml, P < .01) were increased significantly after 10 weeks respectively, but there was no significant difference between the two exercise groups after 10 weeks. 3. In the analyzing of the effects of body composition (body weight, obesity, %fat) and biochemical bone makers that affect height, the lower obesity(β= −.927), the higher body weight(β = .950) and the concentration of OC(β = .267) affect height significantly. CONCLUSIONS: These results suggest that both aerobic and resistance exercise for 10 weeks affect body composition and biochemical bone makers in elementary male students.