Induced metabolic alkalosis and its effects on 400-m racing time

Six trained male athletes who competed regularly in 400 metre races, were studied under control, alkalotic (NaHCO₃) and placebo (CaCO₃) conditions to study the effect of induced metabolic alkalosis on 400 m racing time. Pre and post exercise blood samples in the three conditions were analysed for pH, bicarbonate and base excess. Following ingestion of NaHCO₃, pre-exercise pH, bicarbonate and base excess levels were significantly higher than either control or placebo conditions. In the alkalotic condition the subjects ran significantly (p<0.005) faster (1.52 s) than either the control of placebo conditions. The post-exercise pH, bicarbonate and base excess levels were all lower in the alkalotic condition than in the others. The results suggest that NaHCO₃ can be used as an effective ergogenic aid and support the speculation that the increased extracellular buffering afforded by NaHCO₃ ingestion facilitated efflux of H⁺ from the working tissues, thus decreasing intracellular pH and hence offsetting fatigue.