My 6 week study on L-Carnitine:
An ergogenic aid, according to the International Society of Sports Nutrition (ISSN), is any training technique, mechanical device, or nutritional routine, psychological or pharmacological method that can improve exercise performance or enhance training adaptations (2). The ergogenic aid I chose to review is the supplementation of L-Carnitine . As of the most recent 2014 prohibited list according to the World Anti-Doping, L-Carnitine is not on the list of banned substances for athletes and Olympians. L-Carnitine is found naturally occurring in red meats and dairy products, however, it has been marketed as an ergogenic aid that offers to help in weight management, and the reduction of fatigue, factors that an exercise enthusiast is drawn to.
L-Carnitine, which is found in the human diet, is synthesized by the amino acids lysine and methionine, and is found to increase the deliverance of fatty acids into the mitochondria, thus increasing fatty acid oxidation. This physiological process has led to an increase in L-Carnitine supplementation as a method of possible weight management (4). As described by Speiring et al (2007), L-Carnitine is essential for the transport of long-chain fatty acids across the mitochondrial membranes, potentially increasing the biological function of fat oxidation(1). In addition to its role as a weight management ergogenic aid, it is also believed to be a muscle tissue repair component that helps reduce tissue damage after exercise and aid in remodeling of new tissue. In a study of male athletes underwent a squat and handgrip test while receiving L-Carnitine supplementation to determine if post exercise stress levels, shown by increased levels of hypoxanthine and xanthine oxidase were altered in the subjects. Results concluded that subjects undergoing L-Carnitine doses of 1-3 grams each day for three weeks, showed decreased levels of hypoxanthine and xanthine oxidase post exercise bouts and reported lower levels of muscle soreness (1).
According to the National Institutes for Health (http://ods.od.nih.gov/factsheets/Carnitine-HealthProfessional/), Carnitine has been marketed as an athletic performance enhancer due to its energy production biological factors. Evidence has failed to link additional health factors associated with L-Carnitine supplementation, however, lack of evidence shows that increased levels of L-Carnitine in the body fail to improve exercise performance in healthy subjects.
I, as the athlete of choice, underwent L-Carnitine supplementation for 6 weeks as a means of increasing my energy levels as I was feeling the effects of work, school, and running a fit camp which included a full workout. I was seeking a natural way to help derive more energy from my body as I possibly could. In no manner was I running low on fat reserves, so I believed the energy was there for my body to use, and was hoping that supplementing with L-Carnitine would help utilize fat stores to provide more energy throughout the day. After 6 weeks of supplementation, I did not have specific markers to measure increased energy levels, but from a day-to-day energy feeling, I did not feel that increasing my levels of L-Carnitine provided my body with increased levels, which I believe were already satisfactory from my consumption of red meat and the occasional dairy products.
Currently, according to the National Institutes for Health, an excess intake of Carnitine has led to nausea, vomiting, abdominal cramps and a “fishy” body odor. Some rarer side effects have been seizures in individuals who are more prone to seizure episodes and also possible muscle weakness.
1). Spiering, B. A., Kraemer, W. J., Vingren, J. L., Hatfield, D. L., Fragala, M. S., Jen-Yu, H., & … Volek, J. S. (2007). RESPONSES OF CRITERION VARIABLES TO DIFFERENT SUPPLEMENTAL DOSES OF L-CARNITINE L-TARTRATE. Journal Of Strength & Conditioning Research (Allen Press Publishing Services Inc.), 21(1), 259-264.
2). Kreider, R. B., Wilborn, C. D., Taylor, L., Campbell, B., Almada, A. L., Collins, R., & … Willoughby, D. S. (2010). ISSN exercise & sport nutrition review: research & recommendations. Journal Of The International Society Of Sports Nutrition, 77-49.
4).Senchina, D. S., Stear, S. J., Burke, L. M., & Castell, L. M. (2013). A-Z of nutritional supplements: dietary supplements, sports nutrition foods and ergogenic aids for health and performance: Part 44. British Journal Of Sports Medicine, 47(9), 595-598