L-Carnitine also known as: Carnitine, L-Carnitine, L-Carnitine-Tartrate is a naturally active nutrient found in small quantities in milk, L-Carnitine is made in the body from the amino acids, lysine & methionine. However, during times of high energy needs, such as an intense exercise routine, the need for L-Carnitine can exceed production by the body. Some experts think that L-Carnitine should be classed as a “conditionally essential” nutrient. To make L-Carnitine, your body needs two essential amino acids (lysine & methionine) together with vitamin C, iron, vitamin B6, & niacin. As such, anyone following a low-calorie diet, especially one that's low in red meat, dairy produce, poultry or seafood, will benefit from using L-Carnitine. The benefits are also far greater when it's used over a longer period in combination with regular exercise. Spanish research1, for example, showed that six months of carnitine supplementation (one gram daily) prevented a training-associated drop in muscle carnitine. Endurance athletes such as runners, rugby players & footballers will find that L-Carnitine works well to reduce muscle soreness & increase recovery2. Carefully controlled studies showed that l-carnitine can increase the use of fat for energy. It works by protecting against a carnitine deficiency in the cells that make up the inside of your blood vessels. By protecting against carnitine depletion, carnitine improves the delivery of oxygen to the working muscle during & after exercise3.
Carnitine can also prevent a drop in testosterone caused by physical & mental stress (such as exercise & a low-calorie diet). Studies show that Carnitine can promote the growth & activity of cells in the brain responsible for producing hormones that activate testosterone production. More interesting still, research presented at the US 25th National Strength & Conditioning Association conference showed that Carnitine (2 grams daily) can be highly effective for increasing testosterone levels4,5. What's more, L-Carnitine (2 grams daily) has also been shown to reduce muscle damage, while reducing soreness. A trial published in the American Journal of Physiology shows that muscle "disruption" several days after exercise can be reduced by almost 50% when Carnitine is used3. Several other markers of muscle damage can be reduced, with the researchers concluding that Carnitine can result in "...less accumulation of markers of purine degradation, free radical formation, tissue damage, & muscle soreness." In general, higher doses of L-Carnitine (500-2,500 milligrams) are more effective than smaller amounts (such as 50 or 100 milligrams).
Unlike vitamins & minerals, there is no recognised recommended daily amount (RDA) for L-Carnitine. However, most of the benefits can be seen with a daily intake of 500-2,500 milligrams, with some studies even showing that 1g/day is enough to elicit the same response as 2g6. People using L-Carnitine may experience an increase in energy levels after 7-10 days of use. The muscle soreness caused by intense resistance exercise can be greatly reduced after a few days of use. Several weeks of use generally are required before the potential effect on fat loss & testosterone levels can be noticed. L-Carnitine can work well on its own, in doses of 500-2500 milligrams daily. Several top middle-distance runners are also reported to use higher doses of L-Carnitine with phosphates in the week before a competition, or during periods of heavy training.
There are few side effects from excess consumption of Carnitine. Most common ones are increased appetite, potential diarrhoea and rash. These symptoms usually occur with doses in excess of 5g/day. Carnitine is an easily stackable ingredient and can be used with a variety of other supplements including fat loss products as well as carbohydrates and other recovery supplements such as BCAAs, creatine and protein.
L-Carnitine Supplements are commonly presented & sold as Complementary Medicines, Registered Therapeutic Items or Goods and Formulated Supplementary Sports Foods in Australia. L-Carnitine is not a sole source of nutrition and should be used in conjunction with an appropriate physical training or exercise programme. Not suitable for children or pregnant women. Should only be used under medical or dietetic supervision. Always read the label prior to use.