Twelve Weeks Of Resistance Or Endurance Training Reduces Fat Mass In Postmenopausal Women

BACKGROUND: Prediabetes, often seen alongside obesity and a precursor to type 2 diabetes, is prevalent in over 50% of postmenopausal (PM) women. The PM stage is marked by elevations in fat mass compared to premenopause. The health benefits of exercise are widely acknowledged; however, a clear understanding of body composition changes induced by resistance training (RT) compared to endurance training (ET) is lacking, particularly in PM women. The purpose of this study was to investigate the impacts of 12-week energy-matched (200 kcal) RT or ET on body composition in sedentary PM women with obesity and prediabetes. METHODS: PM women with obesity and prediabetes participating in an ongoing larger study of fat metabolism participated (n = 23; mean ± SD: age: 60 ± 5 yrs.; BMI: 34.16. ± 3.19 kg/m2; BF%: 46.87 ± 3.74%) and were randomized to 12-weeks of ET (n = 12) or RT (n = 11). PM status was defined as cessation of menses for at least 5 years with follicle stimulating hormone (FSH) ≥30 IU/L. All study outcomes were assessed before (PRE) and following (POST) 12 weeks of ET or RT. A DXA scan was completed in a supine position to assess lean mass and both regional adiposity and visceral fat. Statistical analyses were performed in SAS using marginal models to assess main effects of time (PRE & POST), training type (RT vs. ET), and their interaction on outcomes, with age as a covariate. Bonferroni adjustments were applied to post hoc tests, with α set at 0.05. RESULTS: 12 weeks of training led to significant decreases in fat mass (difference of least square means ± standard error [LSM ± SE; POST-PRE]: -1144.69 ± 485.04 kg; time: p = 0.03) and body fat percentage (LSM ± SE; POST-PRE]: -0.92 ± 1.26%; time: p = 0.01. There was no difference between type of training (RT or ET) on fat mass (Training*time p = 0.24) or body fat percentage (Training*time p = 0.55). No differences were observed in lean mass (-624.78 ± 383.48; time: p = 0.12) or bone mineral density (0.003 ± 0.005: time: p = 0.59) between PRE and POST training or between RT and ET (p ≥ 0.05). CONCLUSIONS: When the energy expenditure of exercise training is matched, 12 weeks of either ET or RT results in reductions of fat mass and body fat percentage in PM women with obesity and prediabetes. Both RT and ET are recommended for PM women with obesity and prediabetes to achieve reductions in fat mass and body fat percentage. Supported by: NIH RO1 DK125728