For several years, I’ve been reading about the positive effects of L-carnitine. As a long distance runner, I pay attention to what supplements are recommended for maintaining higher levels of energy during exercise and decreased muscle damage after exercise.


How did L-Carnitine work? Why would L-Carnitine provide more energy and reduce fatigue in an athlete? One articleI read said “Scientists suggest that L-Carnitine may help deliver more blood and more oxygen to muscle during exercise, which helps improve energy generation, wash out substances that produce painful symptoms and repair damaged muscle.”

I wondered, are the positive effects of increased levels of L-Carnitine only for athletes? This same article reported that “In a study of 18 overweight subjects, l-carnitine greatly increased weight loss. The subjects were split into two groups of 9. For 12 weeks, both groups ate a healthy diet and performed moderate exercise. One group was given 2000 mg of l-carnitine, and the other a placebo. In the placebo group, the average weight loss after 12 weeks was one pound. In the l-carnitine group, weight loss averaged 11 pounds.” That seemed like a pretty significant weight loss, and it was in a population that was formerly sedentary.

I looked closely at the dosage used in the study: 2000 mg of L-Carnitine is a larger dose than a person would consume on a daily basis. L-Carnitine is produced in small amounts in the human body, but only about 20 milligrams daily. An average can of energy drink might contain about 50 mg of L-Carnitine. If you don’t want to get your L-Carnitine exclusively from sports drinks, how do you ingest it? And more specifically, how do you consume close to 2000 mg on a daily basis? I rushed out to my local health food store to find the answer.

Back at home with my purchase of a bottle of triple-strength liquid L-Carnitine, I did the math to see how much I needed to come close to the 2000 mg per day consumed in the study. Here are some interesting calculations, using the dosage on the labels and the guidelines for the L-Carnitine that occurs naturally in food:

• One 1 tablespoon of triple strength liquid L-carnitine contains 1500 mg of -Carnitine. That was pretty close to the 2000 mg dosage used in the weight loss study.

• One 7 oz. beef steak contains roughly 190 mg of Carnitine. (By contrast, 100 g of chicken only contains 3.9 mg of L-Carnitine.)

• I’d have to eat over 3 pounds of beef steak to consume the amount of L-Carnitine contained in 1 tablespoon of the liquid supplement. While I enjoy red meat, I’d have to say I don’t have time or inclination to eat three pounds of red meat every day!

Rather than radically modifying my diet, I decided take the plunge and try supplementing my diet with L-Carnitine poured into a spoon. Although I was not especially interested in the weight loss side effect, I was quite intrigued by claims of decreased muscle fatigue because I was beginning to train for a marathon in the spring. And various sources I read suggest that L-Carnitine is (potentially) useful for a wide variety of reasons, not all related to exercise. In addition to aiding weight loss and fatty acid metabolism, some studies say it can help maintain bone mass, provide antioxidant benefits, and relief to asthmatics, among other health benefits.

After all my research, L-Carnitine begins to sound like the magic bullet to cure everyone and everything! I would like to explore its effects on my own running next. I plan to take a daily dose of 1500 mg while training for my marathon in early April, and will report on the results of my informal study later.