Changes in plasma and urinary taurine and amino acids in runners immediately and 24h after a marathon

Changes in urinary and plasma taurine and amino acids have been evaluated i n trained runners competing in the Rotterdam Marathon, 1998, both immediate ly after completing the event and 24h after recovery. There were significan t changes in the urinary amino acids excretion, the majority showing a sign ificant decrease both immediately at the completion of the Marathon and aft er 24h recovery. In contrast urinary taurine excretion increased immediatel y post Marathon, although not significantly as the range of results was wid e. Such changes in urinary taurine correlated with percentage changes in pl asma creatine kinase both immediately post race, (r = 0.972, P < 0.001), an d 24h later (r = 0.872, P < 0.001), possibly indicating that the source of the taurine was muscle. Significant correlations between the individual val ues for urinary and plasma amino acids in all of the athletes were calculat ed for taurine (r = 0.528), glycine (r = 0.853), threonine (r = 0.749), ala nine (r = 0.747), serine (r = 0.620), glutamine (0.614), arginine (r = 0.50 7), histidine (r = 0.470) and valine (r = 0.486). Changes in the mean plasma concentrations of amino acids were comparable to our previously published data (Ward et al., 1999) the majority showing sig nificant decreases immediately and 24h post Marathon, such an adaptation be ing due primarily to their utilisation for gluconeogenesis. However, in con trast, the mean taurine concentrations were significantly elevated both pos t race, P < 0.01 and after 24h, P < 0.05. The physiological response by the muscle to exhaustive exercise, particular ly with regard to changes in plasma and urinary taurine concentrations rema in to be elucidated, but is probably related to muscle function impairment. The increase in taurine urinary excretion could be used as an indicator of muscle damage occurring during exhaustive exercise. Whether taurine supple mentation would minimise such changes is an interesting scientific question and merits investigation.