Possible contribution of skeletal muscle buffers to enhanced anaerobic performance: a brief review.

Sprint-trained athletes demonstrate a remarkable ability to perform exercise which results in fatigue quickly. However, the mechanisms for these enhanced performance capabilities have not been fully elucidated. Elevation in glycolytic enzymes and increased fast-twitch fiber compositions which would result in an enhanced ability to produce ATP do not appear to be capable of accounting for the greatly enhanced performances. Associated with these performances are large accumulations of anaerobic end products which produce decrements in intracellular pH. Because intracellular pH decrements of sufficient magnitude have been shown to inhibit athletic performances, it has been postulated that sprint-trained athletes have an enhanced proton-sequestering capability which would ultimately alter the rate of pH decrement. This would delay the inhibition of the enzymatic and contractile machinery resulting in enhanced performances. The intracellular buffers that are capable of contributing to this enhanced buffering capacity were identified as inorganic phosphate, protein-bound histidine residues, the dipeptide carnosine, bicarbonate, and creatine phosphate. Thus, it has been suggested that increased buffer capacities within sprint-trained athletes may be a contributing factor to his/her enhanced anaerobic performance capacities.