Effect of acute induced metabolic alkalosis on 800-m racing time

Abstract

Six trained middle-distance runners were studied under alkalotic (NaHCO3 ingestion), placebo (CaCO3 ingestion) and control conditions to determine the effect of an acute induced metabolic alkalosis on time to run an 800-m race. Pre-exercise, following NaHCO3 ingestion, pH and standard [HCO3-] was 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. The increase in extracellular buffering following NaHCO3 ingestion facilitated H+ efflux from the cells of working muscle, thereby delaying the decrease in intracellular pH and postponing fatigue. Ingestion of NaHCO3 by trained middle-distance runners prior to an 800-m race has an ergogenic benefit.