Matched work high-intensity interval and continuous running induce similar increases in PGC-1α mRNA, AMPK, p38, and p53 phosphorylation in human skeletal muscle

The aim of the present study was to test the hypothesis that acute high-intensity interval (HIT) running induces greater activation of signaling pathways associated with mitochondrial biogenesis compared with moderate-intensity continuous (CONT) running matched for work done. In a repeated-measures design, 10 active men performed two running protocols consisting of HIT [6 × 3-min at 90% maximal oxygen consumption (Vo2max) interspersed with 3-min recovery periods at 50% Vo2max with a 7-min warm-up and cool-down period at 70% Vo2max] or CONT (50-min continuous running at 70% Vo2max). Both protocols were matched, therefore, for average intensity, duration, and distance run. Muscle biopsies (vastus lateralis) were obtained preexercise, postexercise, and 3 h postexercise. Muscle glycogen decreased (P < 0.05) similarly in HIT and CONT (116 ± 11 vs. 111 ± 17 mmol/kg dry wt, respectively). Phosphorylation (P-) of p38MAPKThr180/Tyr182 (1.9 ± 0.1- vs. 1.5 ± 0.2-fold) and AMPKThr172 (1.5 ± 0.3- vs. 1.5 ± 0.1-fol...