WILKES, D., N. GLEDHILL, and R. SMYTH. Effect of acute induced metabolic alkalosis on 800-m racing time.Med. Set. Sports Exerc., Vol. 15, No. 4, pp. 277–280, 1983. Six trained middle-distance runners were studied under alkalotic (NaHCOaingestion), placebo (CaCO3ingestion), and control conditions to determine the effect of an acute induced metabolic alkalosis on time to run an 800-m race. Pre-exercise, following NaHCO3ingestion, pH and standard [HCO3-] were significantly higher. In the alkalotic condition, subjects ran faster (2.9 s) and the corresponding post-exercise values for blood [lactate] and extracellular H+were higher than in the control and placebo conditions, suggesting an increased anaerobic energy contribution. These results support the speculation that the increase in extracellular buffering following NaHCO3ingestion facilitated H+efflux from the cells of working muscle, thereby delaying the decrease in intracellular pH and postponing fatigue. It is concluded that the ingestion of NaHCO3by trained middle-distance runners prior to an 800-m race has an ergogenic benefit.