Objective: This study aimed to investigate the effects of a 24-week(6-month) combined exercise program on peripheral bone mineral density(BMD) of the hands and ankles, as well as body composition, in habitually active postmenopausal middle-aged women.
Methods: The study cohort comprised 15 healthy postmenopausal women without chronic diseases, and a single-group pre- and post-test repeated measures design was utilized without a control group. The combined exercise program incorporated warm-up exercises, stretching, ladder training, resistance weight training, abdominal exercises, and cool-down exercises. Based on the guidelines of the American College of Sports Medicine(ACSM), the intervention was administered 3 times a week for 100 minutes per session over a 24-week period. The primary outcome variables were body composition (body weight, body mass index[BMI], lean body mass, body fat mass, and body water) and BMD (evaluated separately for the left and right hands and ankles). Data analysis was performed using paired t-tests via the SAS(Statistical Analysis System, Ver. 9.4) program.
Results: Regarding body composition, lean body mass significantly decreased, whereas body fat mass significantly increased(p<.05), however, no significant changes were observed in body weight or BMI. These findings indicate that the combined exercise program exerted a limited additional improvement on peripheral bone mass in this physically active population. Further more, BMD analysis revealed post-intervention decreases or negligible changes across all assessed regions of the hands and ankles compared to baseline, with no statistically significant differences(p>.05).
Conclusion: In conclusion, the 24-week combined exercise program demonstrated limited efficacy in enhancing peripheral BMD among individuals with prior exercise experience. Collectively, considering the progressive nature of natural bone loss in postmenopausal middle-aged women, the program may still hold clinical significance from a preventive standpoint by maintaining current bone density levels. Future research should implement comparative designs that include a non-exercise control group and explore high-intensity exercise protocols that exceed the mechanical stimulus threshold, while thoroughly accounting for site-specific bone tissue responses, exercise intensity, and the potential confounding effects of insufficient mechanical loading.