Author(s)

Keisuke Shiose, Takuro Tobina, Yasuki Higaki, Akira Kiyonaga, Hiroaki Tanaka

Faculty of Nursing and Nutrition, University of Nagasaki, Nagasaki, Japan.
Faculty of Sports and Health Science, Fukuoka University, Fukuoka, Japan.
Fukuoka University Institute for Physical Activity, Fukuoka, Japan.
Graduate School of Sports and Health Science, Fukuoka University, Fukuoka, Japan.

Several metabolic gene expressions are regulated in concert with muscle glycogen status. We hypothesized that intermittent exercise performed at high but sub-maximal intensities with long recovery periods would induce a low glycogen state that would stimul- ate peroxisome proliferator-activated receptor-γ coa- ctivator-1α (PGC1-α) and pyruvate dehydrogenase kinase-4 (PDK-4) gene expression in muscle. Nine young human subjects performed two intermittent exercise sessions. One session consisted of 60 s cycling bouts at VO2max (IE_100%), and the other session consisted of 75 s cycling bouts at 80% VO2max (IE_80%). Twelve bouts of exercise were completed in both sessions with a 4 min rest between each bout. Muscle specimens were obtained at pre-exercise and immediately, 1.5 h and 3 h post-exercise. Muscle gly- cogen was significantly decreased after both sessions (IE_100%, 94.1 ± 5.8 to 38.7 ± 5.5 mmol/kg w.w.; IE80%, 94.6 ± 9.1 to 53.3 ± 4.8 mmol/kg w.w.; both P < 0.05 vs pre-exercise). Muscle glycogen depletion was greater in IE100% than in IE80% (P < 0.05). PGC-1α and PDK- 4 mRNA expression were significantly increased after exercise in both IE100% and IE_80% (PGC-1α: ~3.7 and ~2.9-fold, respectively; PDK-4: ~11.1 and ~3.5-fold, respectively; all P < 0.05). Maximal PDK-4 mRNA expression after exercise was significantly greater in IE_100% than in IE_80% (P < 0.05). In conclusion, high but sub-maximal intermittent exercise decreased muscle glycogen and stimulated PGC-1a and PDK-4 mRNA expression, suggesting that increasing exercise intensity contributes to muscle glycogen depletion and PDK-4 mRNA expression in human skeletal muscle.

Intermittent Exercise; Muscle Glycogen; Peroxisome Proliferator-Activated Receptor-γ Coactivator-1α; Pyruvate Dehydrogenase Kinase-4

Shiose, K. , Tobina, T. , Higaki, Y. , Kiyonaga, A. and Tanaka, H. (2012) Effectiveness of sub-maximal intermittent exercise on muscle glycogen depletion, PGC-1α and PDK-4 gene expression. Open Journal of Molecular and Integrative Physiology, 2, 119-126. doi: 10.4236/ojmip.2012.24017.