Greater glycemic control following low-load, high-repetition resistance exercise compared with moderate-intensity...

Exercise has long been known for its beneficial effects on insulin sensitivity (IS) and glucose handling with both moderate-intensity continuous (MIC) exercise and resistance exercise (RE) inducing beneficial effects. In recent years, low-load, high-repetition (LLHR) RE has emerged as a strategy to increase muscle mass and strength to levels similar to traditional RE; however, the effects of LLHR RE on glucose handling has yet to be investigated. The purpose of this trial was to compare the acute effects of LLHR RE to MIC exercise on post-exercise glycemic control and insulin sensitivity in males and females. Twenty-four (n = 12/sex) participants completed acute bouts of MIC exercise (30 min at 65% V̇O₂_peak) and LLHR (3 circuits, 6 exercises/circuit, 25-35 repetitions/exercise/circuit) matched for time with muscle biopsies immediately pre and post exercise and an oral glucose tolerance test (OGTT) 90 min following exercise. Blood glucose concentrations (p = 0.002, η_p ² = 0.37), glucose AUC (p = 0.002, η_p ² = 0.35) and max glucose concentration (p = 0.003, η_p ² = 0.34) were lower during the post exercise OGTT following LLHR RE compared to MIC exercise. There was a main effect of trial on TBC1D1 Ser²³⁷ phosphorylation (p = 0.04, η_p ² = 0.19) such that it was greater following MIC exercise compared to LLHR RE. Furthermore, phosphorylated ACC Ser⁷⁹ increased following MIC exercise with no change following LLHR RE (p < 0.001, η_p ² = 0.50). Phosphorylation of PTEN Ser³⁸⁰ was greater in males than females during LLHR RE (p = 0.01, η_p ² = 0.27). These findings suggest that LLHR RE is a feasible exercise modality to improve post-exercise glycemic control in both males and females. Trial registration number: NCT06217679.