Athletes: Benefits of L-Leucine Supplementation
How the Use of L-Leucine Can Benefit Athletic Performance
Jan 8, 2009
L-Leucine has long been used in conjunction with L-Isoleucine and L-Valine as a Branched Chain Amino Acid supplement. However, the benefits of its individual use in increasing endurance, power and muscle tissue have often been over looked.
L-Leucine is an essential amino acid, meaning the body is unable to produce it on its own; thus, it must be obtained externally from food sources (such as nuts or brown rice) or through dietary supplementation.
The Benefits for Athletes
Initial studies of L-Leucine were carried out on various types of rat, showing large increases of protein synthesis in adipose tissue, liver and skeletal muscle. In the last two decades similar studies have been carried out on humans, showing a number of benefits in an array of athletic qualities.
A study posted in the European Journal of Applied Physiology, documented the effects L-Leucine had on the performance of a group canoeists.
Thirteen canoeists underwent testing before and after a 6-week training phase, using either capsulated L-Leucine (45mg) or a placebo. They were assessed on their upper body power and the time it took to reach exhaustion while rowing at 70-75% of their maximal aerobic power. The results of the study were significant.
During the 6-week phase upper body strength and power increased in both groups, however, power output increased significantly more in the L-Leucine group. Rowing time also increased for the L-Leucine group, from a starting time of 6.3mins up to 7.3 minutes, where as the placebo group experienced no increase in their times.
The Medical & Physical Therapy Community
Studies carried out on the individual use of L-Leucine supplementation for athletic performance are limited. Despite this, the Medical & Physical Therapy community has done further studies, which highlight obvious benefits for athletes as well.
One such study was done by the Washington University School of Medicine, which measured the acute effects of resistance exercise on muscle protein synthesis rate, in young and elderly men and women. During the study, L-Leucine was incorporated intravenously into mixed-muscle protein in all the subjects, who then followed a 2-week resistance exercise regime.
Before training the elderly subjects presented a lower rate of muscle protein synthesis than their younger counterparts, however, after the 2-week exercise regime, the rate of muscle protein synthesis had increased to a comparable rate in all subjects. In addition to this, the elderly subjects presented a marked decrease in whole body protein breakdown.
These findings demonstrate an obvious benefit of L-Leucine as a muscle preservative but also as a supplement that could enhance muscle-building capabilities due to the increased rate of protein synthesis. In addition to this, one could assume that due to that increased rate, the recovery of an athlete would also be aided.
While these studies show the benefits of using L-Leucine supplementation, it should be noted that to maximize the gains in any of the aforementioned qualities, an optimal training and nutritional programme must be in place first. It is only from this foundation that supplements such as L-Leucine will have their greatest effect and subsequently, athletic performance will be improved.
Sources
Crowe, Weatherson, Bowden. Effects of dietry leucine supplementation on exercise performance, 2006
Connolly DAJ, Sayers SP, McHugh MP. Treatment and prevention of delayed onset muscle soreness. J Strength Cond Res 2003; 17:197-208.
K. E. Yarasheski, J. J. Zachwieja and D. M. Bier Acute effects of resistance exercise on muscle protein synthesis rate in young and elderly men and women 1993
Christopher J. Lynch1, Susan M. Hutson2, Brian J. Patson1, Alain Vaval1, and Thomas C. Vary1. Tissue-specific effects of chronic dietary leucine and norleucine supplementation on protein synthesis in rats
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