Beat Fatigue and Improve Exercise Performance with Carnitine

by: Robbie Durand

Carnitine is bio-synthesized from the amino acids lysine and methionine. L-carnitine can be found in red meat, fish, poultry, and milk. Carnitine helps move fatty acids through the body, allowing the cells to break down fat and use fat deposit stores. The highest concentrations of L-carnitine can be found in red meat. As a result, those on a vegan/ vegetarian diet or those who restrict red meat intake will be most likely to have a deficiency. For example, 100g of beef steak has 94mg of L-carnitine, 100g of chicken breast has 3.9mg of L-carnitine, and 100g of asparagus has 0.195mg of L-carnitine. A new study suggests that carnitine can also improve sprinting capacity by lowering lactic acid production and preventing fatigue.

In a randomized, double-blind placebo-controlled crossover trial, researchers tested the effects of l-carnitine on endurance in 26 professional soccer players. Subjects between the ages of 17-19 years old were randomized to receive either 3g or 4g of carnitine as a powder mixed with fruit juice. Athletes were given their assigned carnitine supplemented drinks 1 hour before endurance testing. The athletes were asked to run on a treadmill beginning at a speed of 8km/h (~4mi/h), which was then later increased to 10km/h (~6mi/h) and progressively 1km/h every 3 minutes until subjects could not continue. Researchers gave them a 1-minute break between accelerations. One week later the test was repeated using a placebo mixed into the fruit juice. Researchers collected blood samples before the trial and before each acceleration in running speed to determine lactic acid levels in the blood. Heart rate was also monitored.

Results showed that athletes taking l-carnitine (both 3g and 4g) had significantly lower lactic acid build up during the test compared to their results taking the placebo. Individuals taking 3g of carnitine had a significant reduction in the lactic acid build-up from the onset of the study at 8km/h (~4mi/h) up to 14km/h (~8mi/h). Also, even at higher speeds from 14 to 16 km/h (8-10mi/h), individuals who were supplemented with 4g carnitine had significantly lower lactate in the blood compared to their samples examined under the placebo. This means that the onset of fatigue was delayed in these athletes during carnitine supplementation. Furthermore, when the athletes were supplemented with carnitine, their perception of fatigue was significantly lower. No significant difference was observed between the two carnitine groups. Overall, Carnitine had a significant effect of lowering lactate levels in the blood, which, in turn, decreases the onset of fatigue.

Abstracted from “The effects of acute L-carnitine supplementation on endurance performance of athletes”, J Strength Cond Res. 2014 Feb;28. Posted February 24, 2015.

MUSCLE MEDIA MAGAZINE FOR MEN
The premier source of training, nutrition, supplements, fat loss and health for men.