by Jeff S. Volek, Ph.D., R.D.
Muscle soreness during exercise results from the accumulation of biochemical end products, meaning muscles become acidic. This usually disappears within minutes or hours after exercise. However, there is a different type of soreness referred to as delayed-onset muscle soreness (DOMS). DOMS is associated with exercise-induced disruption or damage to the muscle fibers — a result of inflammatory reactions and edema (accumulation of fluid) inside muscle fibers. It’s felt 12-48 hours after a strenuous bout of exercise.
DOMS causes a reduction in the force-generating capacity of muscles. Full muscle strength may not return for days or even weeks. Therefore a variety of counter-measures (stretching, ice, compression, massage, non-steroidal anti-inflammatory drugs, and a host of dietary supplements) have been tried with limited success. One promising strategy is the use of branched-chain amino acids (BCAAs).
Researchers from the United Kingdom had high caliber athletes perform a series of damaging exercises consisting of 100 drop jumps. For one week prior to the exercise, and also during the recovery period, athletes consumed a total of 20g of BCAAs daily in two 10-gram doses, in the morning and evening. The ratio of leucine, isoleucine and valine was 2:1:1.
The athletes’ perceived level of muscle soreness peaked two days after exercise and was significantly reduced in the BCAA
group by about 30%. Blood levels of creatine kinase, a marker of muscle damage, peaked one day after exercise and were 22% lower in the BCAA group. Muscle force generating capacity decreased 27% in the placebo group compared to only 18% in the BCAA group. Recovery of force during the four days after exercise was also faster in the BCAA group.
These findings support a promising role of BCAA
supplementation for mitigating the damaging effects of intense exercise and allowing for a more rapid return of muscle performance.