A recent study by American, Finnish and Italian researchers indicates there may be good reasons to take an amino acid supplement during an intense weight training period. Men with an average of approximately five years of weight training experience received either a placebo or an amino acid supplement while performing four weeks of a high-volume weight training program. After the four-week period they performed another two weeks of training at a lower training volume. The men receiving amino acid supplementation took 0.4 grams of the supplement per kilogram (2.2 pounds) of body weight per day. The supplement contained L-leucine, L-lysine, L-isoleucine, L-valine, L-threonine, L- cysteine, L-histidine, L-phenylalanine, L-methionine, L-tyrosine, and L-tryptophan.
Measures of muscle strength and power were determined every week during the high-volume training and after the two weeks of reduced training volume. After the first week of intense training, 1RM squat (11.5 pounds) and bench press (7.5 pounds) significantly decreased in the placebo group, but did not change significantly in the group receiving amino acid supplementation. However, both groups did show a significant decrease in 1RM strength after the second and fourth week of high-volume training. Ballistic power in the bench press at 30 percent of 1RM decreased after the second week of high-volume training in the placebo group, but did not change significantly in the amino acid group. Fatigue of the placebo group during a 20-repetition jump squat did not change significantly after the second week of high-volume training or after the two-week period of reduced training volume. The same measures for the amino acid group showed a trend for reduction in fatigue of approximately 13 to 15 percent.
Several other measures of strength and power showed no significant difference between the two groups. The authors concluded that amino acid supplementation does show some beneficial effects for enhancing recovery and maintaining physical performance during a short-term high-volume resistance training period. (J Strength & Cond Res, 17:250-258)
By Steven J. Fleck, PhD