L-carnitine supplementation can increase L-carnitine levels in muscles and boost athletic endeavor, United Kingdom researchers have found after a 30-year search to locate the optimum L-carnitine delivery mechanism to the musculature.
L-carnitine, a vitamin-like nutrient, occurs naturally in the human body and is essential for turning fat into energy.
Writing in the Journal of Physiology, the researchers from the School of Biomedical Sciences at the University of Nottingham Medical School said a combination of L-carnitine and carbohydrates delivered the measurable increase and concomitant athletic boost.
“This is the first demonstration that human muscle total carnitine (TC) can be increased by dietary means and results in muscle glycogen sparing during low-intensity exercise (consistent with an increase in lipid utilization) and a better matching of glycolytic, PDC and mitochondrial flux during high-intensity exercise, thereby reducing muscle anaerobic ATP production,” they wrote. “Furthermore, these changes were associated with an improvement in exercise performance.”
The researchers emphasized the dual metabolic effect of the L-carnitine supplementation at both low and high-intensity exercise levels, which led to a decrease in anaerobic energy production and a decrease in muscle lactate accumulation. Participants also registered lower perceived exertion as well as increased work output.
Lead researcher Professor Paul Greenhaff said the findings were “very exciting” and a demonstration of evidence-based nutrition, which was “rare in the sports nutrition market.” He continued, “Most of the studies to date have been heart-based, not skeletal muscle. These findings should spur a fresh round of research in this area.”
Journal of Physiology 389(Pt 4):963-973, 2011