Millions of Americans suffer from illnesses that can be prevented or improved through regular physical activity.1 In fact, physical activity is so important to our health, the government recently revised exercise guidelines, stating that all Americans should now get 60 minutes of daily exercise.2 Unfortunately, the pain and exhaustion from exercise is often too much for people so they don’t stick to a regular exercise program.
The nutrient L-Carnitine (ehl-car-nih-teen) assists in the process of converting fat into fuel for the body and scientists have found a nutritional link between L-Carnitine and improved exercise performance and recovery. High-end athletes are very familiar with L-Carnitine as it was among the top three most commonly reported dietary supplements used by athletes at the 2000 Olympic Games.3 Recent clinical studies have shown that adequate intakes of the nutrient may not only lengthen and optimize workouts but also reduce pain during the post-exercise recovery phase for all types of athletes, even the “weekend warriors.”
Nutrition for efficient exercise and recovery
L-Carnitine, a key component in the Krebs cycle, is responsible for facilitating the use of one of our primary energy sources, fat, by shuttling fatty acids into the powerhouse of the cell to be burned as fuel.4 Fat is the body’s most concentrated source of energy and can fuel hours of exercise, if burned efficiently in the cell.5 In the absence of L-Carnitine, the cycle of burning fats for energy is incomplete and exercise endurance is compromised.
Clinical research consistently shows an improved post-exercise – or recovery – period with
L-Carnitine supplementation. Dr. Maria Giamberardino and her colleagues looked at the effect of
L-Carnitine on the post-exercise recovery of untrained individuals. In the study, subjects were given 3g placebo/day for 3 weeks, followed by a standardized exercise test. Shortly afterwards, the same subjects were given 3g L-Carnitine/day for 3 weeks, again followed by the same standardized exercise test. The researchers reported that the exercise performed after L-Carnitine supplementation gave rise to significantly less pain and tenderness than the same exercise performed after placebo treatment. In addition, exercise-induced muscle cell damage was significantly less after L-Carnitine supplementation.6
In a study published earlier this year in the American Journal of Physiology, Endocrinology and Metabolism, Drs. William Kraemer and Jeff Volek and their colleagues from the University of Connecticut also reported on the beneficial effects of L-Carnitine on post-exercise recovery. In this balanced (included one-week washout period), placebo controlled, crossover study, recreationally trained athletes were given either a placebo or 2g L-Carnitine (as L-CARNIPURE® L-Carnitine
L-Tartrate) for 3 weeks, prior to the performance of a moderate-intensity squat exercise. L-Carnitine
L-Tartrate supplementation helped with post-exercise recovery as evidenced by the significantly reduced free radical formation, tissue damage and muscle soreness, as compared to placebo.7
Dr. Silvia Maggini’s research also lends support for L-Carnitine’s positive effect on post-exercise recovery, though she measured recovery in the short term (minutes) after exercise, as opposed to the longer term studies mentioned above. In a double blind, placebo-controlled, crossover study, she studied trained and untrained individuals’ recovery from strenuous exercise, after supplementing with placebo or 2g L-Carnitine/day (as L-Carnitine L-Tartrate) over a five-day period. Seventy-five percent of participants benefited from L-Carnitine supplementation with a nearly 20 percent improvement in ability to recover and exert energy in the 25-minute period following the exercise routine.8
Suggested mechanisms for improved recovery
Although L-Carnitine may improve recovery through several mechanisms of action, scientists hypothesize that the protective effect of L-Carnitine may be partly due to a favorable effect on blood flow regulation during and after exercise. The ability to deliver more blood and consequently more oxygen to the muscle during the early stages of exercise helps to improve energy metabolism. This effect of L-Carnitine is also important when the muscle has already been damaged, as it will help in the repair process and in washing out the substances responsible for producing the painful symptoms.6, 7
Where can L-Carnitine be found?
L-Carnitine is produced in small quantities in the human body (approximately 20 milligrams of
L-Carnitine is produced daily), but this amount is equivalent to only about 10 percent of the nutrient used daily by the average person. In addition, a diet including two to three servings of lean meat such as lamb, beef, pork and poultry, as recommended in the food guide pyramid, can provide approximately 100-300 milligrams of L-Carnitine to the body daily.9, 10
However, in order to reap the benefits of enhanced recovery, additional L-Carnitine may be needed, typically above the level that can be obtained through eating L-Carnitine rich foods. Supplemental
L-Carnitine is usually seen as a single nutrient or in formulations marketed for enhancement of exercise and metabolism. Single nutrient supplements generally contain levels associated with health benefits, offering a range between 250-500 milligrams of L-Carnitine. Health food stores, pharmacies and supermarkets throughout the U.S. carry L-Carnitine supplements.
Lonza, Inc. founded the L-Carnitine InfoCenter to provide credible and reliable information on
L-Carnitine for health professionals, educators and communicators. Lonza manufactures pharmaceutical grade L-Carnitine, approved by an Expert Panel as Generally Recognized as Safe (GRAS). Additional information can be found in the Human Nutrition center at www.carnitine.com.
- National Center for Chronic Disease Prevention and Health Promotion. Physical Activity and Good Nutrition: Essential Elements to Prevent Chronic Diseases and Obesity In: At a Glance 2002. 2002. http://www.cdc.gov/nccdphp/aag/aag_dnpa.htm.
- National Academies Press. Physical Activity (Ch. 12) In: Dietary Reference Intakes for Energy, Carbohydrates, Fiber, Fat, Protein and Amino Acids 2002. Pp 697-736.
- Corrigan, Kazlauskas. Report: A Survey of Medications Taken by Athletes at the Sydney Olympics, 2000.
- Swart, et al., The Effect Of L-Carnitine Supplementation On Plasma Carnitine Levels And Various Performance Parameters Of Male Marathon Athletes. Nutrition Research 17(1997) Pp 405-414.
- Burke ER. What Causes Muscle Fatigue (Ch.2, 3)?” In: Optimal Muscle Recovery. 1999. Avery Publishing Group, Garden City Park, NY. Pp 33-36.
- Giamberardino, et al., Effects of Prolonged L-Carnitine Administration on Delayed Muscle Pain and CK Release After Eccentric Effort. International Journal of Sports Medicine 17(1996) Pp 320-324.
- Volek, et al., L-Carnitine L-Tartrate Supplementation Favorably Affects Markers of Recovery From Exercise Stress. American Journal of Physiology, Endocrinology and Metabolism 282(2002)
- Maggini, et al., L-Carnitine Supplementation Results in Improved Recovery After Strenuous Exercise: A Preliminary Study. Annals of Nutrition Metabolism 44(2000) Pp 75-96.
- Leibovitz, 1998. L-Carnitine: The Energy Nutrient. Keats Publishing, Los Angeles, CA. Pp 12-17.
- DiPalma. L-Carnitine: Its Therapeutic Potential. American Family Physician 34(1986) Pp 127-130.