Written by Chrystal Moulton, Staff Writer. In research on 26 professional soccer players, those taking carnitine had significantly less build up of lactic acid, a sign of muscle fatigue, in endurance exercises.
Achieving top performance in the most natural, cost-effective way is desired by all athletes and active individuals alike. With all the ads out there supporting quick–sometimes risky solutions for energy and endurance, it’s no wonder people are looking for better and safer options. Carnitine, an amino acid naturally found in red meat and dairy products, has been touted for its ability to facilitate fat-burning for energy. However, whether it may affect endurance is yet to be determined.
In a double-blind randomized 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 into 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 test 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 (p<0.05). Lactic acid or lactate is responsible for the burning pain experienced during exercise and is a sign of muscular fatigue. Individuals taking 3g of carnitine had significant reduction in lactic acid build up from the onset of the study at 8km/h (~4mi/h) up to 14km/h (~8mi/h) (p<0.05). 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 (p<0.05). 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 (p<0.05). 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, lowers the onset of fatigue.
Source: Orer, Gamze E., and Nevin A. Guzel. “The effects of acute L-carnitine supplementation on endurance performance of athletes.” The Journal of Strength & Conditioning Research 28.2 (2014): 514-519.
© 2014 by the National Strength & Conditioning Association.
Posted February 24, 2015.
Chrystal Moulton BA, PMP, is a 2008 graduate of the University of Illinois at Chicago. She graduated with a bachelor’s in psychology with a focus on premedical studies and is a licensed project manager. She currently resides in Indianapolis, IN.
Reference:
Orer GE, Guzel NA. The effects of acute L-carnitine supplementation on endurance performance of athletes. J Strength Cond Res. 2014 Feb;28(2):514-9.
