In the December 2011 Journal of the International Society of Sports Nutrition there was an excellent paper titled, “Potential therapeutic effects of branched-chain amino acids supplementation on resistance exercise-based muscle damage in humans.” It reviewed the therapeutic effects of BCAA (isoleucine, leucine, and valine) supplementation on muscle recuperation. BCAAs have recently been shown to improve muscle recovery from resistance exercise. Here are some of the findings reported in the review paper:
-One study evaluated the effects on BCAA administration 30 minutes before, immediately after, and then four days after intense eccentric contractions. At the end of the study, no differences in muscle strength were observed between groups that took BCAAs; muscle discomfort was decreased up to four days after exercise in the supplemented group. After blood work was examined, subjects who ingested the BCAA mixture over four days post-exercise presented a reduction of serum enzymes associated with muscle damage creatine kinase, or CK (from 48 to 96 hours), myoglobin (from 24 to 96 hours), and muscle soreness (from 24 to 96 hours) compared with those who took the placebo. The results showed that BCAA supplementation may reduce muscle soreness, and this can be related to some biochemical markers of muscle damage.
-Another study reported reduced markers of muscle enzyme damage with BCAAs. Male subjects took BCAAs (1.8g of leucine, 0.75g of isoleucine, and 0.75g of valine) in the three weeks before and one week during a high-intensity total-body resistance exercise (3 sets of 8 reps max and 8 exercises) and observed that serum CK (i.e., marker of muscle damage) was significantly reduced in the BCAA-supplemented group during and after training.
-The final study was on the effects of BCAA supplementation (3.5g of leucine, 2.1g of isoleucine, and 1.7g of valine divided into four daily doses) on eccentric exercise-induced muscle damage. Subjects performed 12 sets of 10 repetitions at 120% of concentric 1 rep maximum, then they consumed a BCAA supplement 30 minutes before, 11⁄2 hours after, between lunch and dinner, and before bed; on the following two days, four doses of BCAA supplementation were given between meals. At the end of the study, muscle soreness increased after exercise, but it was 64% lower in the group that took the BCAAs than it was in those who took the placebo. In summary, BCAAs seem to reduce muscle soreness although it does not seem to enhance strength recovery after resistance exercise. BCAA supplementation may further prevent muscle damage, which may play a role in muscle hypertrophy.