Post-absorptive muscle protein turnover affects resistance training hypertrophy

Paul T. Reidy, Michael S. Borack, Melissa M. Markofski, Jared M. Dickinson, Christopher S. Fry, Rachel R. Deer, Elena Volpi, Blake B. Rasmussen

Research output: Contribution to journalArticlepeer-review

41 Scopus citations

Abstract

Purpose: Acute bouts of resistance exercise and subsequent training alters protein turnover in skeletal muscle. The mechanisms responsible for the changes in basal post-absorptive protein turnover and its impact on muscle hypertrophy following resistance exercise training are unknown. Our goal was to determine whether post-absorptive muscle protein turnover following 12 weeks of resistance exercise training (RET) plays a role in muscle hypertrophy. In addition, we were interested in determining potential molecular mechanisms responsible for altering post-training muscle protein turnover. Methods: Healthy young men (n = 31) participated in supervised whole body progressive RET at 60–80% 1 repetition maximum (1-RM), 3 days/week for 3 months. Pre- and post-training vastus lateralis muscle biopsies and blood samples taken during an infusion of 13C6 and 15N phenylalanine and were used to assess skeletal muscle protein turnover in the post-absorptive state. Lean body mass (LBM), muscle strength (determined by dynamometry), vastus lateralis muscle thickness (MT), myofiber type-specific cross-sectional area (CSA), and mRNA were assessed pre- and post-RET. Results: RET increased strength (12–40%), LBM (~5%), MT (~15%) and myofiber CSA (~20%) (p < 0.05). Muscle protein synthesis (MPS) increased 24% while muscle protein breakdown (MPB) decreased 21%, respectively. These changes in protein turnover resulted in an improved net muscle protein balance in the basal state following RET. Further, the change in basal MPS is positively associated (r = 0.555, p = 0.003) with the change in muscle thickness. Conclusion: Post-absorptive muscle protein turnover is associated with muscle hypertrophy during resistance exercise training.

Original languageEnglish (US)
Pages (from-to)853-866
Number of pages14
JournalEuropean Journal of Applied Physiology
Volume117
Issue number5
DOIs
StatePublished - May 1 2017

Keywords

  • Growth
  • Ribosome biogenesis
  • Skeletal muscle
  • Strength training
  • mTORC1

ASJC Scopus subject areas

  • Orthopedics and Sports Medicine
  • Public Health, Environmental and Occupational Health
  • Physiology (medical)

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