Document Detail

Effects of different intensities of resistance exercise on regulators of myogenesis.
MedLine Citation:
PMID:  19826309     Owner:  NLM     Status:  In-Process    
A single bout of high-intensity resistance exercise is capable of activating the expression of various genes in skeletal muscle involved in hypertrophy such as myosin heavy chain (MHC) isoforms, myogenic regulatory factors (MRFs), and growth factors. However, the specific role exercise intensity plays on the expression of these genes is not well defined. The purpose of this study was to investigate the effects of exercise intensity on MHC (type I, IIA, IIX), MRF (Myo-D, myogenin, MRF-4, myf5), and growth factor (insulin-like growth factor [IGF]-1, IGF-1 receptor [IGF-R1], mechano-growth factor [MGF]) mRNA expression. Thirteen male participants (21.5 +/- 2.9 years, 86.1 +/- 19.5 kg, 69.7 +/- 2.7 in.) completed bouts of resistance exercise involving 4 sets of 18-20 repetitions with 60-65% 1 repetition maximum (1RM) and 4 sets of 8-10 repetitions with 80-85% 1RM. Vastus lateralis biopsies were obtained immediately before exercise, and at 30 minutes, 2 hours, and 6 hours after each bout. The levels of mRNA expression were determined using real-time polymerase chain reaction. Data were analyzed using 2 x 4 multivariate analysis of variance (p <or= 0.05). For both intensities, MHC type IIX, IGF-1, IGF-R1, MGF, Myo-D, myogenin, MRF-4, and myf5 mRNA were all significantly increased in response to resistance exercise by 2 hours after exercise, whereas myostatin and the cyclin-dependent kinase inhibitor p27(kip) were decreased at 2 hours after exercise (p < 0.05). Resistance exercise between 60-85% 1RM upregulates the mRNA expression of MHC and factors involved in myogenic activation of satellite cells while concomitantly decreasing expression of myogenic inhibitors.
Colin D Wilborn; Lemuel W Taylor; Michael Greenwood; Richard B Kreider; Darryn S Willoughby
Related Documents :
20032509 - Pgc-1alpha plays a functional role in exercise-induced mitochondrial biogenesis and ang...
16357069 - Effect of voluntary exercise on peripheral tissue glucocorticoid receptor content and t...
1936089 - Regulation of muscle sympathetic nerve activity during exercise in humans.
12600679 - Mitochondrial, sarcoplasmic membrane integrity and protein degradation in heart and ske...
24917689 - Urinary creatine at rest and after repeated sprints in athletes: a pilot study.
11098159 - Nutritional supplementation and resistance exercise: what is the evidence for enhanced ...
2999569 - Fitness: a new look at an old term (measurements of human aerobic performance).
21527519 - Hospitalization for pain in patients with sickle cell disease treated with sildenafil f...
22497979 - Multidisciplinary lifestyle intervention in the obese: its impact on patients' percepti...
Publication Detail:
Type:  Journal Article; Research Support, Non-U.S. Gov't    
Journal Detail:
Title:  Journal of strength and conditioning research / National Strength & Conditioning Association     Volume:  23     ISSN:  1533-4287     ISO Abbreviation:  J Strength Cond Res     Publication Date:  2009 Nov 
Date Detail:
Created Date:  2009-11-10     Completed Date:  -     Revised Date:  -    
Medline Journal Info:
Nlm Unique ID:  9415084     Medline TA:  J Strength Cond Res     Country:  United States    
Other Details:
Languages:  eng     Pagination:  2179-87     Citation Subset:  IM    
Department of Exercise Sport Science, University of Mary Hardin Baylor, Belton, Texas, USA.
Export Citation:
APA/MLA Format     Download EndNote     Download BibTex
MeSH Terms

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine

Previous Document:  Strength and Conditioning Practices of United States High School Strength and Conditioning Coaches.
Next Document:  Anthropometric and Performance Comparisons in Professional Baseball Players.