| Effects of L-carnitine L-tartrate supplementation on muscle oxygenation responses to resistance exercise. | |
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MedLine Citation:
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PMID: 18545197 Owner: NLM Status: MEDLINE |
Abstract/OtherAbstract:
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Previous research has shown that L-carnitine L-tartrate (LCLT) supplementation beneficially affects markers of hypoxic stress following resistance exercise. However, the mechanism of this response is unclear. Therefore, the primary purpose of this study was to determine the effects of LCLT supplementation on muscle tissue oxygenation during and after multiple sets of squat exercise. Nine healthy, previously resistance-trained men (25.2 +/- 6.years, 91.2 +/- 10.2 kg, 180.2 +/- 6.3 cm) ingested 2 g.d of LCLT or an identical placebo for 23 days in a randomized, balanced, crossover, double-blind, placebo-controlled, repeated-measures study design. On day 21, forearm muscle oxygenation was measured during and after an upper arm occlusion protocol using near infrared spectroscopy (NIRS), which measures the balance of oxygen delivery in relation to oxygen consumption. On day 22, subjects performed 5 sets of 15 to 20 repetitions of squat exercise with corresponding measures of thigh muscle oxygenation, via NIRS, and serial blood draws. Compared to the placebo trial, muscle oxygenation was reduced in the LCLT trial during upper arm occlusion and following each set of resistance exercise. Despite reduced oxygenation, plasma malondealdehyde, a marker of membrane damage, was attenuated during the LCLT trial. There were no differences between trials in the vasoactive substance prostacyclin. In conclusion, because oxygen delivery was occluded during the forearm protocol, it is proposed that enhanced oxygen consumption mediated the reduced muscle oxygenation during the LCLT trial. Enhanced oxygen consumption would explain why hypoxic stress was attenuated with LCLT supplementation. |
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Authors:
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Barry A Spiering; William J Kraemer; Disa L Hatfield; Jakob L Vingren; Maren S Fragala; Jen-Yu Ho; Gwendolyn A Thomas; Keijo Häkkinen; Jeff S Volek |
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Publication Detail:
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Type: Journal Article; Randomized Controlled Trial; Research Support, Non-U.S. Gov't |
Journal Detail:
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Title: Journal of strength and conditioning research / National Strength & Conditioning Association Volume: 22 ISSN: 1533-4287 ISO Abbreviation: J Strength Cond Res Publication Date: 2008 Jul |
Date Detail:
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Created Date: 2008-07-10 Completed Date: 2008-09-10 Revised Date: - |
Medline Journal Info:
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Nlm Unique ID: 9415084 Medline TA: J Strength Cond Res Country: United States |
Other Details:
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Languages: eng Pagination: 1130-5 Citation Subset: IM |
Affiliation:
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Human Performance Laboratory, Department of Kinesiology, University of Connecticut, Storrs, Connecticut, USA. |
Export Citation:
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APA/MLA Format Download EndNote Download BibTex |
| MeSH Terms | |
Descriptor/Qualifier:
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Adult Carnitine / administration & dosage* Cross-Over Studies Dietary Supplements Double-Blind Method Exercise* Humans Male Malondialdehyde / blood Muscle, Skeletal / metabolism* Oxygen / metabolism* Oxygen Consumption Spectroscopy, Near-Infrared Tartrates / administration & dosage* Vitamin B Complex / administration & dosage* |
| Chemical | |
Reg. No./Substance:
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0/Tartrates; 12001-76-2/Vitamin B Complex; 541-15-1/Carnitine; 542-78-9/Malondialdehyde; 7782-44-7/Oxygen |
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine
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