Effects of Exercise Intervention on Body Composition in Middle-aged and Older Women : A DEXA-based Study

This study compared DXA-based changes in body composition following a 12-week exercise intervention in middle-aged and elderly women. Participants included 49 women living in the G region, divided into middle-aged women (MAW, n=27) and older adult women (OAW, n=22). The exercise program combined aerobic and resistance training and was conducted three times per week for 60 minutes over 12 weeks, consisting of adaptation (weeks 1–4), progression (weeks 5–8), and strengthening phases (weeks 9–12), in accordance with ACSM (2025) guidelines. Data were analyzed using SPSS 26.0, with paired t-tests for within-group comparisons and independent t-tests for between-group comparisons (α=0.05).<br/> In MAW, significant reductions were observed in body weight, fat mass, total body fat percentage, and trunk fat percentage, along with decreases in muscle mass and bone mineral density. No significant changes were found in BMI, bone mineral content, muscle area, or ASM-related indices. In OAW, fat mass, total body fat percentage, and trunk fat percentage significantly decreased, while muscle mass, ASM, and ASM/height² also showed significant reductions. No significant changes were noted in body weight, BMI, bone mineral content, muscle area, or ASM/weight.<br/> Post-intervention comparisons revealed significantly greater muscle area, muscle mass, and ASM in MAW, whereas no group differences were observed in fat-related variables or relative muscle indices. These findings indicate that 12 weeks of combined exercise effectively reduced body fat in both groups; however, differences in muscle-related outcomes between groups appear to reflect absolute post-intervention levels rather than intervention effects.