Take L-carnitine to improve athletic performance, burn fat, and build muscle. A new review suggests that in addition to helping the body use fat for energy, carnitine supplementation improves recovery and minimizes muscle damage.
Carnitine is an essential nutrient for humans that has numerous physiological effects. In addition to improving fat burning, you can experience the following benefits by raising muscle carnitine levels:
• Better vascular endothelial function, meaning improved blood flow and superior cardiovascular function.
• Better blood flow to muscle tissues, and greater oxygen availability, resulting in less muscle damage from training.
• Less damage by free radicals and better removal of waste products during intense training, leading to less soreness.
• Faster recover from intense exercise allowing for greater training volume.
For instance, a study that used trained male triathletes showed improved high-intensity exercise performance from taking carnitine for 6 months. The participants took 2 grams of carnitine with 80 grams of carbohydrates twice daily and performed their regular workouts during the study period. They increased muscle carnitine content by 21 percent, showing that the carnitine effectively loaded into the muscle—a common issue if carnitine is not taken with carbs or omega-3 fats because insulin must be elevated for it to load.
Results showed that during a 30-minute exercise trial at 50 percent of maximal, participants used 55 percent less muscle glycogen compared to a placebo group. During a 30-minute trial at 80 percent max, muscle lactate buildup was 44 percent lower, while work output was 35 percent greater than the placebo group.
Muscle lactate buildup is a limiting factor that inhibits performance, but taking carnitine allowed for better removal of the lactate. This, along with the better fuel utilization, allowed the participants to work harder, and it felt easier—perception of effort was lower in the carnitine group.
Other benefits of taking carnitine include better brain function and motivation. It has also been shown to improve the muscle building response to strength training and decrease inflammation caused by endurance exercise.
Be aware that for best results with carnitine you need to take at least 2 grams a day (3 to 6 grams have proved very beneficial) with omega-3 fats, fenugreek, or carbs in order “load” the carnitine into the muscle. Also, plan on taking it for 6 months to get the best results—the researchers in the triathlete study note that long-term supplementation is what set the study apart from shorter trials that have not shown significant performance results from carnitine in athletes.
Wall, B., et al. Chronic Oral Ingestion of L-Carnitine and Carbohydrate Increases Muscle Carnitine Content and Alters Muscle Fuel Metabolism During Exercise in Humans. The Journal of Physiology. 2011. 589, 963-973.
Huang, A., et al. Role of Supplementary L-Carnitine in Exercise and Exercise Recovery. Medicine and Science in Sports. 2012. 59, 135-142.