EFFECTS OF INDUCED ALKALOSIS ON PERFORMANCE IN THOROUGHBREDS DURING A1,600-M RACE

There is considerable debate regarding the ergogenic effects of sodium bicarbonate (NaHCO3) on racing performance in horses. Anecdotal evide nce suggests that NaHCO3 improves performance by increasing the buffer ing capacity of the blood and delaying the onset of hydrogen ion-induc ed fatigue. In a cross-over study, 16 Thoroughbred racehorses were giv en an aqueous solution of NaHCO3 (0.4 g/kg in 1 litre H2O) or a contro l treatment (1 litre H2O) before a 1600-m race. Treatments were admini stered 3 h before the race, which was the time to peak buffering capac ity (2.5-3.0 h) determined in a separate study. Before the race, there was a significant increase in venous HCO3- and pH in the NaHCO3-treat ed horses. After the race, there was a significant increase in venous blood pH and lactate in the NaHCO3-treated horses. Collectively, the d ata suggest an improved buffering capacity of the blood after NaHCO3 t reatment. However, there was no change in race times or venous partial pressure of carbon dioxide. Therefore, the administration of NaHCO3 p rovided no ergogenic benefit to horses competing in a 1,600-m race.