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) 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 NaHCO3 ingestion facili tated H+ efflux from the cells of working muscle, thereby delaying the decrease in intracellular pH and postponing fatigue. It is concluded that the in gestion of NaHCO3 by trained middle-distance runners prior to an 800-m race has an ergogenic benefit. Verf.-Referat