Title | Post-absorptive muscle protein turnover affects resistance training hypertrophy. |
Publication Type | Journal Article |
Year of Publication | 2017 |
Authors | Reidy PT, Borack MS, Markofski MM, Dickinson JM, Fry CS, Deer RR, Volpi E, Rasmussen BB |
Journal | Eur J Appl Physiol |
Volume | 117 |
Issue | 5 |
Pagination | 853-866 |
Date Published | 2017 May |
ISSN | 1439-6327 |
Keywords | Absorptiometry, Photon, Humans, Male, Muscle Proteins, Muscle Strength, Quadriceps Muscle, Resistance Training, Young Adult |
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 C and N 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. |
DOI | 10.1007/s00421-017-3566-4 |
Alternate Journal | Eur. J. Appl. Physiol. |
PubMed ID | 28280974 |
PubMed Central ID | PMC5389914 |
Grant List | T32 HD007539 / HD / NICHD NIH HHS / United States UL1 TR000071 / TR / NCATS NIH HHS / United States TL1 TR001440 / TR / NCATS NIH HHS / United States R01 AR049877 / AR / NIAMS NIH HHS / United States P30 AG024832 / AG / NIA NIH HHS / United States UL1 TR001439 / TR / NCATS NIH HHS / United States |