Fig. 1: Resistance exercise upregulates glycolysis in human skeletal muscle.

A–D The enzyme activity of hexokinase (HK), phosphofructokinase (PFK), pyruvate kinase (PK), and lactate dehydrogenase (LDH) were analyzed from muscle biopsies of healthy participants before (SED Pre), within 10 min after (0 h Post), and 1 h after (1 h Post) a one-legged resistance exercise (RE) bout (n = 14 for HK, PFK and LDH; n = 12 for PK). Time-matched control muscle samples were obtained from the non-exercised leg at 1 h post-RE (SED Post). *P < 0.05 vs. SED in each group. One-way ANOVA was used with multiple comparisons. E Plasma lactate was measured at baseline (B), immediately post-exercise (0), 30 min post-exercise (30), and 60 min post-exercise (60) to represent the “spill over” of lactate from muscle to blood (n = 17). † indicates a significant difference between the immediate post-exercise and baseline lactate samples (P < 0.05). F RNA-Seq data for glycolysis-related genes in muscle after resistance exercise training (RET) (n = 18). Data were analyzed from RNA-Seq results presented in our previous publication¹⁸. G–J Muscles were obtained before (pre-RET) and after (post-RET) 12 weeks of RET and subsequently analyzed for HK, PFK, PK, and LDH activity (n = 14 for HK, PFK, and PK; n = 10 for LDH). *P < 0.05 vs. pre-RET. Paired two-tailed t-test was used. Values are expressed as individual data points, Log₂ FC, or mean ± SD. Significant labeled P-values in each panel from left to right are as follows: panel A = 0.001 and 0.007; panel B = 0.004; panel E = < 0.001; panel G = 0.009; panel J = 0.004.