Fig. 5.

Gene expression in whole tissue. mRNA content of peroxisome proliferator-activated receptor-γ coactivator-1α (PGC-1α; A) and p53 (B) before (rest), immediately postexercise (+0 h), and 3 h (+3 h) after a single session of high-intensity interval exercise (HIIE) performed at the same absolute intensity before (pre-HVT) and after (post-HVT) 40 sessions of twice-daily high-volume, high-intensity interval training (HVT) in the vastus lateralis muscle of young healthy men (n = 9). Values are expressed relative to TATA-binging protein (TBP), glyceraldehyde 3-phosphate dehydrogenase (GAPDH), and β-actin (ACTB) housekeeping genes [control (Ctrl)]. ○ (Pre-HVT) and ◇ (post-HVT) represent individual values; white (pre-HVT) and gray (post-HVT) bars represent mean values. *P < 0.05 vs. rest in the same group; †P < 0.05 vs. same time point of post-HVT trial by 2-way ANOVA with repeated measures, followed by Tukey’s honestly significant difference post hoc test or by preplanned paired t-test for rest values between trials. To more clearly depict fold changes in postexercise values from potentially different rest values in the untrained and trained state, an inset has been added to each graph; the error bars represent the SE.