You are here

UCF Digital Collections ยป ETD Collection

Intramuscular anabolic signaling and endocrine response following different resistance exercise protocols in trained men

Download pdf | Full Screen View

Date Issued:
2015
Abstract/Description:
The mammalian/mechanistic target of rapamycin complex 1 (mTORC1) signaling pathway appears to be the primary regulator of protein synthesis and growth. While resistance exercise paradigms are often divided into hypertrophy (HYP) and strength (STR) protocols, it is unknown whether these protocols differentially stimulate mTORC1 signaling. The purpose of this study was to examine mTORC1 signaling in conjunction with circulating hormone concentrations following a typical lower-body HYP and STR resistance exercise protocol. Ten resistance-trained men (24.7(&)#177;3.4y; 90.1(&)#177;11.3kg; 176.0(&)#177;4.9cm) performed each resistance exercise protocol in a random, counterbalanced order. Blood samples were obtained at baseline (BL), immediately (IP), 30 minutes (30P), 1 hour (1H), 2 hours (2H), and 5 hours (5H) post-exercise. Fine needle muscle biopsies were completed at BL, 1H, and 5H. Electromyography of the vastus lateralis was also recorded during each protocol. HYP and STR produced a similar magnitude of muscle activation across sets. Myoglobin and lactate dehydrogenase concentrations were significantly greater following STR compared to HYP (p=0.01-0.02), whereas the lactate response was significantly higher following HYP compared to STR (p=0.003). The GH, cortisol, and insulin responses were significantly greater following HYP compared to STR (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 HYP compared to STR. Phosphorylation status of all other signaling proteins including mTOR (mammalian target of rapamycin), p70S6k (ribosomal S6 kinase 1), and RPS6 (ribosomal protein S6) were not significantly different between trials. Despite significant differences in markers of muscle damage and the endocrine response following STR and HYP, both protocols appeared to elicit similar mTORC1 activation in resistance-trained men.
Title: Intramuscular anabolic signaling and endocrine response following different resistance exercise protocols in trained men.
41 views
21 downloads
Name(s): Gonzalez, Adam, Author
Hoffman, Jay, Committee Chair
Stout, Jeffrey, Committee Member
Fukuda, David, Committee Member
Willoughby, Darryn, Committee Member
University of Central Florida, Degree Grantor
Type of Resource: text
Date Issued: 2015
Publisher: University of Central Florida
Language(s): English
Abstract/Description: The mammalian/mechanistic target of rapamycin complex 1 (mTORC1) signaling pathway appears to be the primary regulator of protein synthesis and growth. While resistance exercise paradigms are often divided into hypertrophy (HYP) and strength (STR) protocols, it is unknown whether these protocols differentially stimulate mTORC1 signaling. The purpose of this study was to examine mTORC1 signaling in conjunction with circulating hormone concentrations following a typical lower-body HYP and STR resistance exercise protocol. Ten resistance-trained men (24.7(&)#177;3.4y; 90.1(&)#177;11.3kg; 176.0(&)#177;4.9cm) performed each resistance exercise protocol in a random, counterbalanced order. Blood samples were obtained at baseline (BL), immediately (IP), 30 minutes (30P), 1 hour (1H), 2 hours (2H), and 5 hours (5H) post-exercise. Fine needle muscle biopsies were completed at BL, 1H, and 5H. Electromyography of the vastus lateralis was also recorded during each protocol. HYP and STR produced a similar magnitude of muscle activation across sets. Myoglobin and lactate dehydrogenase concentrations were significantly greater following STR compared to HYP (p=0.01-0.02), whereas the lactate response was significantly higher following HYP compared to STR (p=0.003). The GH, cortisol, and insulin responses were significantly greater following HYP compared to STR (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 HYP compared to STR. Phosphorylation status of all other signaling proteins including mTOR (mammalian target of rapamycin), p70S6k (ribosomal S6 kinase 1), and RPS6 (ribosomal protein S6) were not significantly different between trials. Despite significant differences in markers of muscle damage and the endocrine response following STR and HYP, both protocols appeared to elicit similar mTORC1 activation in resistance-trained men.
Identifier: CFE0005621 (IID), ucf:50203 (fedora)
Note(s): 2015-05-01
Ph.D.
Education and Human Performance, Dean's Office EDUC
Doctoral
This record was generated from author submitted information.
Subject(s): mTORC1 -- mTOR pathway -- hormone hypothesis -- volume -- intensity
Persistent Link to This Record: http://purl.flvc.org/ucf/fd/CFE0005621
Restrictions on Access: campus 2016-05-15
Host Institution: UCF

In Collections