Duncan Ogilvie (MSc, CSCS, ASCC) – Director of DO Training
Recently I have been asked the same question by several of my professional athlete clients. They wanted to know my opinion on using a supplement of L-Carnitine in their diets and would it benefit them and their performance? I decided to put together the following article to give you DO Training’s thoughts on L-Carnitine supplementation.
Well let’s start with, what is L-Carnitine? Carnitine exists in three forms – L-Carnitine, Acetyl L Carnitine, and propionyl-L-Carnitine. The basic explanation is that Carnitine is a substance that helps the body turn fat into energy. Your body produced Carnitine in the liver and kidneys and stores it in the skeletal muscles, heart, brain, and sperm. It’s thought that your body produces adequate amounts; however due to ailments and disease some people are deficient and have low levels of Carnitine and supplementation would be essential. A more scientific definition of Carnitine is that it is a quaternary ammonium compound biosynthesized from the amino acids lysine and methionine.(1) In living cells, Carnitine is required for the transport of fatty acids from the cytosol into the mitochondria during the breakdown of lipids (fats) for the generation of metabolic energy. Carnitine helps create useable energy via fatty acid with the aid of Acetyle CoA and the citric acid cycle. (2) Carnitine in its three forms has been researched and used by many scientists and medical practitioners’ worldwide to help with illnesses and disease. Research studies have shown it to be beneficial for heart conditions (angina, heart failure and attacks), Alzheimer’s, Kidney disease, (3) male infertility and hyperthyroidism. (4) This article focuses on the effects of L-Carnitine supplementation for elite athletes.
At first glance many would see L-Carnitine as a weight loss supplement, and many take its liquid or pill form for this exact reason, but is this its only potential benefit? Recent studies conducted by the University of Maryland Medical Center show that oral L-Carnitine reduces fat mass, increases muscles mass, and reduces fatigue. These factors may well contribute to effective weight loss, and obviously have benefits for the high performance and elite athlete. A published study in 2011 showed that using L-Carnitine supplementation for 6 months in a well controlled study; demonstrated not only an increased in L-Carnitine level within the muscle in subjects without L-Carnitine deficiencies, but also had a significant impact on muscle metabolism and performance. (5)
L-Carnitine has been shown to decrease your cravings and appetite, increase your energy during exercise and increase your metabolic rate, all of which would be beneficial for the high performance athlete. Consider an athlete in the off season; L-Carnitine supplementation might be desirable for the “easy gainer” athlete, to help maintain weight and avoid unwanted weight gain. For the endurance athlete lipids are the main fuel for energy for prolonged activity. L-Carnitine is essential in order for the body to process these lipids into energy, thus making it desirable for any endurance athlete to ensure adequate L-Carnitine levels via supplementation. It has also been shown to induce a significant post-exercise decrease in plasma lactate, which is formed and used continuously under fully aerobic conditions. An athlete enduring “2-a-day” session might find use of this supplement beneficial for assistance in recovery between sessions. Further studies have indicated that L-Carnitine supplementation can attenuate the deleterious effects of hypoxic training and speed up recovery from exercise stress. (6) Recent data have indicated that L-Carnitine plays a decisive role in the prevention of cellular damage and favorably affects recovery from exercise stress. (7) Uptake of L-Carnitine by blood cells may induce at least three mechanisms which are – The stimulation of hematopoiesis, (The formation of blood cellular components). Dose-dependent inhibition of collagen-induced platelet aggregation, the prevention of programmed cell death in immune cells. This would lead us to the conclusion that there is some great benefits’ to be gained from L-Carnitine supplementation by the elite athlete. Using L-Carnitine can assist in training, competition, and recovery from strenuous exercise; as well as improving also in regenerative properties of individual athletes.
There are some side effects that one should be aware of when taking L-Carnitine. These can be unusual sleep pattern if taken in the evenings; nausea, headache, and diarrhea if taken in excess. While these side effects are not desirable, they pose no major health risk and if the athlete sticks to the correct dosage they should not have to worry about suffering any effects from these. However is should be noted that athletes with low or boarder-line thyroid levels, should not take L-Carnitine as it may impair the action of your thyroid hormone.
L-Carnitine supplementation is recommended in a dosage of between 500-1000mg; 2 to 3 times a day, taken with food. L-Carnitine supplements are readily available in health food and supplement stores and sold as capsules, tablets, liquid and powder form. You should expect to pay in the region of £20-30 pound for a month’s supply.
It must be noted that the highlighted studies for L-Carnitine have been conducted over a period of 3 months or greater. Any supplementation of L-Carnitine should be taken regularly throughout the course of an athlete’s season and not seen as a quick fix or pick me up supplement. More and more research is emerging over the positives of L-Carnitine supplementation. So in conclusion taking L-Carnitine is a smart decision for any athlete wanting to improve body composition by burning greater amounts of lipids (fats) and being able to train at a higher level. An effective dosage of L-Carnitine will; in simple terms allow you to recover faster, work harder and burn more fat while doing it!
1- Steiber A, Kerner J, Hoppel C (2004). “Carnitine: a nutritional, biosynthetic, and functional perspective”. Mol. Aspects Med. 25 (5-6): 455–73
2- Olpin S (2005). “Fatty acid oxidation defects as a cause of neuromyopathic disease in infants and adults”. Clin. Lab. 51 (5-6): 289–306.
3- Pettegrew JW, Levine J, McClure RJ (2000). “Acetyl-L-Carnitine physical-chemical, metabolic, and therapeutic properties: relevance for its mode of action in Alzheimer’s disease and geriatric depression.” Mol Psychiatry. 5:616-632.
4- Fugh-Berman A (2000). “Herbs and dietary supplements in the prevention and treatment of cardiovascular disease.” Prev Cardiology. 3:24-32.
5- Wall BT, Stephens FB, Constantin-Teodosiu D, Marimuthu K, Macdonald IA, Greenhaff PL (2011). “Chronic oral ingestion of L-carnitine and carbohydrate increases muscle carnitine content and alters muscle fuel metabolism during exercise in humans”. J Physiol 589 (4): 963-73.
6- Karlic, H., & Lohninger, A. (2004). “Supplementation of l-carnitine in athletes: does it make sense?” Nutrition, 20(7/8), 709-715.
7- Volek JS, KraemerWJ, Rubin MR, G´omez AL, Ratamess NA & Gaynor P (2002). “L-carnitine L-tartrate supplementation favorably affects markers of recovery from exercise stress.” AmJ Physiol Endocrinol Metab 282, E474–E482.