RMR, RER, And VO2 MAX Are Not Affected By 12 Weeks Of Either Resistance Or Endurance Training In Postmenopausal Women

Alayne J. Thompson, Sadio P. Fenner, Mostafa M. Ali, Alayne J. Thompson, Paul A. Baker, Mostafa M. Ali, Susan E. O’ Donnell, Josh I. Murry, Cameron M. McCarthy, Michael J. Ormsbee FACSM, Robert C. Hickner FACSM. BACKGROUND: Prediabetes, commonly associated with obesity, serves as a precursor to type 2 diabetes, and affects over 50% of postmenopausal (PM) women. The PM stage is characterized by increases in fat mass and a decline in Resting Metabolic Rate (RMR). These changes are also negatively associated with Respiratory Exchange Rate (RER) and VO2 max. While the health benefits of exercise are well-recognized, there is limited understanding of how energy-matched ET and RT specifically affect RMR, RER, and VO₂ max in PM women. The purpose of this study was to investigate the impacts of 12-week energy-matched RT or ET on RMR, RER, and VO2max in sedentary PM women with obesity and prediabetes. METHODS: The study included PM women with obesity and prediabetes that participatinged in an ongoing larger study of fat metabolism (n = 22; mean ± SD: age: 60 ± 5 yrs.; BMI: 34.16. ± 3.19 kg/m2; BF%: 46.87 ± 3.74%) participated. Participants 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 at 200 kcal/week, with 3 sessions per week. A 30-minute RMR was conducted after a 30 min. rest period upon arrival to their study visit using a PARVO metabolic cart. Statistical analyses were conducted with Prism using marginal models to determine the main effect of time (PRE & POST), training (RT or ET), and interaction effects on study outcomes with age treated as a covariate. Post hoc analyses were adjusted for multiple comparisons using the Bonferroni adjustment with α set at 0.05. RESULTS: 12 weeks of training did not lead to significant changes in RMR (p = 0.67), RER (p = 0.23), or VO2max (p = 0.86). CONCLUSIONS: 12 weeks of either ET or RT did not result in changes of RMR, RQ, or VO2max in our study group of PM women with obesity and prediabetes. Grant or Funding information: NIH RO1 DK125728 Supported by: NIH RO1 DK125728