High force development augments skeletal muscle signalling in resistance exercise modes equalized for time under tension

Sebastian Gehlert, Frank Suhr, Katrin Gutsche, Lena Willkomm, Julia Kern, Daniel Jacko, Axel Knicker, Thorsten Schiffer, Henning Wackerhage, Wilhelm Bloch

Research output: Contribution to journalArticlepeer-review

63 Citations (Scopus)

Abstract

How force development and time under tension (TUT) during resistance exercise (RE) influence anabolic signalling of skeletal muscle is incompletely understood. We hypothesized that high force development during RE is more important for post-exercise-induced signalling than submaximal and fatiguing RE with lower force development but similar TUT. Twenty-two male subjects (24 ± 6 years, 181 ± 9 cm, 79 ± 2 kg) performed three distinct RE modes in the fed state with equal TUT but distinct force output: (i) maximal eccentric RE (ECC, n = 7) three sets, eight reps, 100 % eccentric dynamic force; (ii) standard RE (STD, n = 7), three sets, 10 reps, 75 % dynamic force; and (iii) high fatiguing single-set RE (HIT, n = 8), 20 reps, 100 % eccentric-concentric force; vastus lateralis biopsies were collected at baseline, 15, 30, 60, 240 min and 24 h after RE, and the signalling of mechanosensitive and mammalian target of rapamycin (mTOR)-related proteins was determined. The phosphorylation levels of pFAK(Tyr397), pJNK(Thr183/Tyr185), pAKT(Thr308/Ser473), pmTOR(Ser2448), p4E-BP1(Thr37/46), p70s6k(Thr389)/(Ser421/Thr424) and pS6(Ser235/236) were significantly higher in ECC than those in STD and HIT at several time points (P < 0.01). pJNK(Thr183/Tyr185) and pS6(Ser235/236) levels were significantly higher in type II myofibres in ECC compared with STD and HIT. HIT exerted throughout the weakest signalling response. We conclude that high force development during acute RE is superior for anabolic skeletal muscle signalling than fatiguing RE with lower force output but similar TUT. Our results suggest that this response is substantially driven by the higher activation of type II myofibres during RE.

Original languageEnglish
Pages (from-to)1343-1356
Number of pages14
JournalPflugers Archiv : European Journal of Physiology
Volume467
Issue number6
Early online date29 Jul 2014
DOIs
Publication statusPublished - Jun 2015

Bibliographical note

Acknowledgments
The authors thank Katharina Hermanns and the technicians Anika Voss, Bianca Collins and Mojghan Ghilav (Institute of Cardiovascular Research and Sport Medicine, Department of Molecular and Cellular Sport Medicine) for expert technical assistance.

Conflict of interest
All authors disclose any professional relationship with companies or manufacturers who will benefit from the results of the present study.

Funding
This investigation was funded by the Federal Institute of Sports Science (BISP) IIA1-507 070103/09-10. The funders had no role in study design, data collection

Keywords

  • resistance exercise
  • skeletal muscle signalling
  • mTOR signalling
  • myofibre types
  • mechanical stress
  • protein synthesis

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