Open AccessIntramuscular anabolic signaling and endocrine response following high volume and high intensity resistance exercise protocols in trained men
Author(s) -
Gonzalez Adam M.,
Hoffman Jay R.,
Townsend Jeremy R.,
Jajtner Adam R.,
Boone Carleigh H.,
Beyer Kyle S.,
Baker Kayla M.,
Wells Adam J.,
Mangine Gerald T.,
Robinson Edward H.,
Church David D.,
Oliveira Leonardo P.,
Willoughby Darryn S.,
Fukuda David H.,
Stout Jeffrey R.
Publication year - 2015
Publication title -
physiological reports
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.918
H-Index - 39
ISSN - 2051-817X
DOI - 10.14814/phy2.12466
Subject(s) - anabolism , mtorc1 , endocrinology , medicine , insulin resistance , hormone , signal transduction , pi3k/akt/mtor pathway , biology , insulin , biochemistry
Abstract Resistance exercise paradigms are often divided into high volume ( HV ) or high intensity ( HI ) protocols, however, it is unknown whether these protocols differentially stimulate mTORC 1 signaling. The purpose of this study was to examine mTORC 1 signaling in conjunction with circulating hormone concentrations following a typical HV and HI lower‐body resistance exercise protocol. Ten resistance‐trained men (24.7 ± 3.4 years; 90.1 ± 11.3 kg; 176.0 ± 4.9 cm) performed each resistance exercise protocol in a random, counterbalanced order. Blood samples were obtained at baseline ( BL ), immediately ( IP ), 30 min (30P), 1 h (1H), 2 h (2H), and 5 h (5H) postexercise. Fine needle muscle biopsies were completed at BL , 1H, and 5H. Electromyography of the vastus lateralis was also recorded during each protocol. HV and HI produced a similar magnitude of muscle activation across sets. Myoglobin and lactate dehydrogenase concentrations were significantly greater following HI compared to HV ( P = 0.01–0.02), whereas the lactate response was significantly higher following HV compared to HI ( P = 0.003). The growth hormone, cortisol, and insulin responses were significantly greater following HV compared to HI ( P = 0.0001–0.04). No significant differences between protocols were observed for the IGF ‐1 or testosterone response. Intramuscular anabolic signaling analysis revealed a significantly greater ( P = 0.03) phosphorylation of IGF ‐1 receptor at 1H following HV compared to HI . Phosphorylation status of all other signaling proteins including mTOR , p70S6k, and RPS 6 were not significantly different between trials. Despite significant differences in markers of muscle damage and the endocrine response following HV and HI , both protocols appeared to elicit similar mTORC 1 activation in resistance‐trained men.