Brief intense interval exercise activates AMPK and p38 MAPK signaling and increases the expression of PGC-1 in human skeletal muscle
Subjects then performed four 30-s all out cycling bouts on the air-braked ergometer (Repco) with 4 min of rest between bouts. Immediately following the first and last exercise bout, the gauze was quickly removed and a biopsy sample was obtained through one of the incisions (within 10 s following the completion of the exercise bout)
…given the potency of interval training to stimulate the signaling pathways that lead to mitochondrial biogenesis, but not those responsible for muscle growth, it appears that such training may be closer to endurance type training that resistance training in terms of activation of signaling pathways
In summary, the present study showed that four 30-s bouts of all out cycling increased phosphorylation of AMPK1, AMPK2, and p38 MAPK immediately following exercise and the mRNA expression of PGC-1 after 3 h of recovery. Specific signaling through AMPK and p38 MAPK to PGC-1 may therefore explain in part the metabolic remodeling induced by intense interval exercise training, including mitochondrial biogenesis and an increased capacity for glucose and fatty acid oxidation.