TITLE:
Extremely low-volume, high-intensity interval training improves exercise capacity and increases mitochondrial protein content in human skeletal muscle
AUTHORS:
Jasmin K. Ma, Trisha D. Scribbans, Brittany A. Edgett, J. Colin Boyd, Craig A. Simpson, Jonathan P. Little, Brendon J. Gurd
KEYWORDS:
PGC-1α; Mitochondrial Biogenesis; High-Intensity Interval Training; SIRT1; Aerobic Fitness
JOURNAL NAME:
Open Journal of Molecular and Integrative Physiology,
Vol.3 No.4,
November
21,
2013
ABSTRACT:
Purpose:
The purpose of the present study was to evaluate whole-muscle content of
several proteins involved in the regulation of skeletal muscle mitochondrial
protein content and anaerobic capacity following 4 weeks of extremely
low-volume high-intensity interval training (HIT). Methods: Young, healthy,
recreationally active adult males (n = 8) trained 4 times a week for 4 weeks on
a cycle ergometer. Each session involved 4 min of total exercise comprised of
eight 20 s intervals at ~170% of peak aerobic power separated by 10 s rest.
Muscle biopsies were taken prior to (pre) and ~72 hrs post-training (post). Par-
ticipants completed an incremental peak oxygen up- take (VO2peak)
test and a Wingate test pre-, mid-, and post-training. Results: VO2peak
was elevated (p p -1·min-1, mid: 43.4 ± 2.5 ml·kg-1·min-1,
post-: 47.2 ± 2.9 ml·kg-1·min-1). Wingate mean power also
increased with training (pre-: 701.0 ± 73.0 W, mid-: 745.5 ± 73.3 W, post-:
786.8 ± 80.0 W). While maximal citrate synthase activity was unchanged, protein
expression of the mitochondrial protein cytochrome c oxidase (COX) subunit I
(+27%; p p p = 0.08) increased. Increases (p α (+19%), and nuclear PGC-1α (+46%) were also observed after 4
weeks of HIT. No changes were observed in the whole-muscle contents of
PDHe1a, PDK4, SIRT1, mTOR, S6K1, MCT1, or PFK protein. Conclusions: These
results demonstrate that several mitochondrial protein (but not citrate
synthase activity), PGC-1α protein
content, and exercise capacity can be improved in only 4 min of total training
time per day, 4 days per wk using HIT cycle training.