Is Post Resistance Exercise Glucose Tolerance Associated With Exercise Protocol And Load In Post-menopausal Women?

INTRODUCTION: Glucose tolerance (GT), muscle mass (MM) and strength are thought to decline in post-menopausal women (PMW). Resistance exercise (RE) with heavy weights and moderate-to-low repetitions (HWLR) is associated with MM, body composition (BC) and strength adaptations and is thus thought to enhance muscle glucose uptake and hence, post-exercise glucose tolerance (PEGT). RE with low weights and high repetitions (LWHR), have also shown to be efficient for muscle adaptations. The magnitude of these adaptations has been suggested to depend on training load. However, as PMW exercise physiology remains under-studied, it is unknown if acute RE can enhance PEGT and which protocol has the most potential. PURPOSE: To compare the impact of HWLR and LWHR on PEGT; to determine training and BC contributing factors in healthy, non-active PMW. METHODS: After baseline testing (oral glucose tolerance test; OGTT, fat mass and fat-free mass (FFM); DXA, upper and lower body maximal strength), twelve healthy and inactive (exercising <2 times/wk) PMW (66 ± 6y) performed tree conditions in a randomized order (control, HWLR and LWHR), following an OGTT. 2-h plasma glucose, glucose area under the curve (AUC) and total weight lifted (TWL) were used as surrogates of PEGT and session load, respectively. RESULTS: There was a significant effect of RE on glucose AUC (p < 0.005) and 2-h glucose (p = 0.04) with no difference between HWLR and LWHR (2-h glucose: 8.8 ± 2.5 vs 7.0 ± 1.6 and 7.4 ± 2.0 mmol/L; AUC: 1109 ± 234 vs 9545 ± 149 and 974 ± 192 mmol/L*120 min for control, HWLR and LWHR respectively). There was no significant correlation for TWL, TWL/kgFFM, fat mass and FFM with PEGT. However, there was a significant correlation between baseline glucose AUC and post-RE glucose AUC in HWLR (r = 0.6, p = 0.03) and LWHR (r = 0.8, p < 0.001) protocols, and a tendency towards significance for FFM and baseline glucose AUC (-0.6, p = 0.07). CONCLUSION: Our results demonstrate that HWLR and LWHR can enhance GT parameters in healthy PMW. Further research is warranted to elucidate training or physiologic contributing factors, which reinforces the importance of expanding exercise physiology research in PMW to ultimately develop precision approaches in exercise recommendations. FUNDING: Chaire de recherche pour un vieillissement en santé - Fondation B Breton et JL Gravel