The Effects of Leucine Supplementation on Lean Mass and Strength in Young and Midlife Adults

Leucine is well known as a supplement that has the ability to augment lean mass and strength. Multiple studies on the benefits of leucine supplementation in older age groups have been published. Thus, this review focuses on examining articles studying the effects of leucine supplementation in younger and middle-aged subjects. In such studies, strength and body composition were assessed and comparisons made between those subjects taking placebo versus those taking the actual supplement. Fat mass, lean tissue mass, and maximum strength measurements are key variables used to assess the success of the supplementation as they indicate body composition changes as well as strength gains. Furthermore, the effects of leucine supplementation during periods of inactivity or bed rest were also examined. In this review, the CINAHL and Pubmed databases were used to choose a total of ten articles with young adult (18-35) and middle-aged (36-55) subjects and then analyzed on the categorical basis of gender, age group, training program length, and leucine dose. Common limitations of studies were discussed as well as implications of use of leucine supplementation in the younger population.