Document Detail

Influence of dietary nitrate supplementation on human skeletal muscle metabolism and force production during maximum voluntary contractions.
MedLine Citation:
PMID:  23354414     Owner:  NLM     Status:  Publisher    
Dietary nitrate supplementation, which enhances nitric oxide (NO) bioavailability, has previously been shown to contribute to improved exercise performance by reducing both oxygen cost and energy expenditure. In contrast, previous studies have indicated that NO can lower force production in vitro. To examine the role of dietary nitrates in regulating force generation under normal physiological conditions, we undertook an extended nitrate supplementation regime and determined force output and energy cost with a repeated isometric maximum voluntary contraction (MVC) protocol. In a double-blind, randomized, crossover design, eight participants received 0.5 l/day of nitrate-rich (BR) or nitrate-depleted (PL) beetroot juice for 15 days and completed an exercise protocol consisting of 50 MVCs at 2.5 h, 5 days and 15 days after the beginning of the supplementation period. No significant reduction in force output was determined for BR relative to PL for the peak contraction, the mean or the end force, and no significant time effect was found over the course of the supplementation period. There was a reduction in the mean PCr cost of exercise averaged over the BR supplementation trials, but this did not reach statistical significance for end exercise (BR 15.10 ± 4.14 mM, PL 17.10 ± 5.34 mM, P = 0.06) or the mean throughout the protocol (BR 15.96 ± 4.14 mM, PL 17.79 ± 4.51 mM, P = 0.06). However, a significant reduction in PCr cost per unit force output was found for BR at end exercise (P = 0.04). These results indicate that, under normal physiological conditions, increased NO bioavailability is not associated with a reduction of force-generating capability in human skeletal muscle and confirm that nitrate supplementation reduces the PCr cost of force production.
Jonathan Fulford; Paul G Winyard; Anni Vanhatalo; Stephen J Bailey; Jamie R Blackwell; Andrew M Jones
Related Documents :
11725594 - Validity of the ek scale: a functional assessment of non-ambulatory individuals with du...
20184624 - Validity of oxycon mobile in measuring inspiratory capacity in healthy subjects.
23954024 - Self-managed loaded exercise versus usual physiotherapy treatment for rotator cuff tend...
23619184 - Are older adults who volunteer to participate in an exercise study fitter and healthier...
18781654 - Health-related fitness and trainability in children with cystic fibrosis.
18676514 - Reduced exercise capacity in children born very preterm.
Publication Detail:
Type:  JOURNAL ARTICLE     Date:  2013-1-26
Journal Detail:
Title:  Pflugers Archiv : European journal of physiology     Volume:  -     ISSN:  1432-2013     ISO Abbreviation:  Pflugers Arch.     Publication Date:  2013 Jan 
Date Detail:
Created Date:  2013-1-28     Completed Date:  -     Revised Date:  -    
Medline Journal Info:
Nlm Unique ID:  0154720     Medline TA:  Pflugers Arch     Country:  -    
Other Details:
Languages:  ENG     Pagination:  -     Citation Subset:  -    
NIHR Exeter Clinical Research Facility, University of Exeter Medical School, Exeter, UK,
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:  Rictor encounters RhoGDI2: the second pilot is taking a lead.
Next Document:  The Rac1 hypervariable region in targeting and signaling: a tail of many stories.