Document Detail


Intramuscular metabolism during low-intensity resistance exercise with blood flow restriction.
MedLine Citation:
PMID:  19213931     Owner:  NLM     Status:  MEDLINE    
Abstract/OtherAbstract:
Although recent studies have reported that low-intensity resistance training with blood flow restriction could stress the muscle effectively and provide rapid muscle hypertrophy and strength gain equivalent to those of high-intensity resistance training, the exact mechanism and its generality have not yet been clarified. We investigated the intramuscular metabolism during low-intensity resistance exercise with blood flow restriction and compared it with that of high-intensity and low-intensity resistance exercises without blood flow restriction using (31)P-magnetic resonance spectroscopy. Twenty-six healthy subjects (22 +/- 4 yr) participated and performed unilateral plantar flexion (30 repetitions/min) for 2 min. Protocols were as follows: low-intensity exercise (L) using a load of 20% of one-repetition maximum (1 RM), L with blood flow restriction (LR), and high-intensity exercise using 65% 1 RM (H). Intramuscular phosphocreatine (PCr) and diprotonated phosphate (H(2)PO(4)(-)) levels and intramuscular pH at rest and during exercise were obtained. We found that the PCr depletion, the H(2)PO(4)(-) increase, and the intramuscular pH decrease during LR were significantly greater than those in L (P < 0.001); however, those in LR were significantly lower than those in H (P < 0.001). The recruitment of fast-twitch fiber evaluated by inorganic phosphate splitting occurred in only 31% of the subjects in LR, compared with 70% in H. In conclusion, the metabolic stress in skeletal muscle during low-intensity resistance exercise was significantly increased by applying blood flow restriction, but did not generally reach that during high-intensity resistance exercise. This new method of resistance training needs to be examined for optimization of the protocol to reach equivalence with high-intensity resistance training.
Authors:
Tadashi Suga; Koichi Okita; Noriteru Morita; Takashi Yokota; Kagami Hirabayashi; Masahiro Horiuchi; Shingo Takada; Tomohiro Takahashi; Masashi Omokawa; Shintaro Kinugawa; Hiroyuki Tsutsui
Publication Detail:
Type:  Journal Article; Research Support, Non-U.S. Gov't     Date:  2009-02-12
Journal Detail:
Title:  Journal of applied physiology (Bethesda, Md. : 1985)     Volume:  106     ISSN:  8750-7587     ISO Abbreviation:  J. Appl. Physiol.     Publication Date:  2009 Apr 
Date Detail:
Created Date:  2009-04-01     Completed Date:  2009-05-29     Revised Date:  -    
Medline Journal Info:
Nlm Unique ID:  8502536     Medline TA:  J Appl Physiol     Country:  United States    
Other Details:
Languages:  eng     Pagination:  1119-24     Citation Subset:  IM    
Affiliation:
Graduate School of Program in Lifelong Learning Studies, Hokusho University, Ebetsu, Hokkaido, Japan.
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MeSH Terms
Descriptor/Qualifier:
Adult
Female
Humans
Hydrogen-Ion Concentration
Hypertrophy
Magnetic Resonance Spectroscopy
Male
Muscle Fibers, Fast-Twitch / physiology
Muscle Fibers, Skeletal / physiology
Muscle, Skeletal / blood supply*,  metabolism*,  physiology
Organ Size / physiology
Phosphates / metabolism
Phosphocreatine / metabolism
Physical Fitness / physiology*
Regional Blood Flow / physiology
Sex Characteristics
Weight Lifting / physiology*
Young Adult
Chemical
Reg. No./Substance:
0/Phosphates; 67-07-2/Phosphocreatine

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


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