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Cited by 77Muscle metabolism and nutritionBiochemical effects in animalsCardiovascular and exercise physiology

Long-term administration of L-carnitine to humans: effect on skeletal muscle carnitine content and physical performance

Wächter, Sandra, Vogt, Michael, Kreis, Roland, Boesch, Chris, Bigler, Peter, Hoppeler, Hans, Krähenbühl, Stephan·2002·Clinica Chimica Acta
DOI 10.1016/s0009-8981(01)00804-x
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Abstract

Background Long-term administration of high oral doses of L-carnitine on the skeletal muscle composition and the physical performance has not been studied in humans.Methods Eight healthy male adults were treated with 2 x 2 g of L-carnitine per day for 3 months. Muscle biopsies and exercise tests were performed before, immediately after, and 2 months after the treatment. Exercise tests were performed using a bicycle ergometer for 10 min at 20%, 40%, and 60% of the individual maximal workload (P(max)), respectively, until exhaustion.Results There were no significant differences between V(O(2)max), RER(max), and P(max) between the three time points investigated. At submaximal intensities, the only difference to the pretreatment values was a 5% increase in V(O(2)) at 20% and 40% of P(max) 2 months after the cessation of the treatment. The total carnitine content in the skeletal muscle was 4.10 +/- 0.82 micromol/g before, 4.79 +/- 1.19 micromol/g immediately after, and 4.19 +/- 0.61 micromol/g wet weight 2 months after the treatment (no significant difference). Activities of the two mitochondrial enzymes citrate synthase and cytochrome oxidase, as well as the skeletal muscle fiber composition also remained unaffected by the administration of L-carnitine.Conclusions Long-term oral treatment of healthy adults with L-carnitine is not associated with a significant increase in the muscle carnitine content, mitochondrial proliferation, or physical performance. Beneficial effects of the long-term treatment with L-carnitine on the physical performance of healthy adults cannot be explained by an increase in the carnitine muscle stores.

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  • The lack of performance improvements seen in the majority of these studies can be attributed to a failure to increase muscle carnitine content.

    “However, it is clear that the lack of performance improvements seen in the majority of these studies can be attributed to a failure to increase muscle carnitine content [[189], [190], [191]].”

    From Nutritional Considerations for the Vegan Athlete (2023) · cites this paper as [191]

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Authors
Wächter, S., Vogt, M., Kreis, R., Boesch, C., Bigler, P., Hoppeler, H., & Krähenbühl, S.
Affiliations
University of Bern (CH)
Corresponding author
Krähenbühl, Stephan
ORCID
Venue
Clinica Chimica Acta
Publisher
Elsevier BV
Published
2002-04
Volume
318
Issue
1-2
Pages
51-61
ISSN
0009-8981 (ISSN-L)
DOI
10.1016/s0009-8981(01)00804-x
OpenAlex
W2164747025
Cited by
77
References
53
Citations by year
2026: 1 · 2023: 6 · 2021: 4 · 2020: 3 · 2019: 5 · 2018: 9 · 2017: 5 · 2016: 2 · 2015: 4 · 2014: 3 · 2013: 7 · 2012: 2
FWCI
0.85
Type
journal article
Language
en
Open access
closed
Licence
www.elsevier.com/tdm/userlicense/1.0/ (tdm)
Locations
  • Clinica Chimica Acta (publishedVersion)
  • PubMed (publishedVersion)
Topics
  • Life Sciences › Biochemistry, Genetics and Molecular Biology › Cell Biology › Muscle metabolism and nutrition
  • Health Sciences › Medicine › Physiology › Biochemical effects in animals
  • Health Sciences › Medicine › Complementary and alternative medicine › Cardiovascular and exercise physiology
Keywords
L-carnitine, long-term supplementation, physical performance, exercise capacity, mitochondrial enzymes, citrate synthase, cytochrome c oxidase, muscle fiber composition, mitochondrial proliferation, healthy adults
MeSH terms
Adult, Carnitine, Chromatography, High Pressure Liquid, Exercise Test, Humans, Male, Mitochondria, Muscle, Magnetic Resonance Spectroscopy, Anaerobic Threshold, Muscle, Skeletal, Muscle Fibers, Skeletal, Lactic Acid

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