Effects of induced alkalosis on performance in thoroughbreds during a 1,600-m race.
There is considerable debate regarding the ergogenic effects of sodium bicarbonate (NaHCO3) on racing performance in horses. Anecdotal evidence suggests that NaHCO3 improves performance by increasing the buffering capacity of the blood and delaying the onset of hydrogen ion-induced fatigue. In a cross-over study, 16 Thoroughbred racehorses were given an aqueous solution of NaHCO3 (0.4 g/kg in 1 litre H2O) or a control treatment (1 litre H2O) before a 1600-m race. Treatments were administered 3 h before the race, which was the time to peak buffering capacity (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-treated horses. After the race, there was a significant increase in venous blood pH and lactate in the NaHCO3-treated horses. Collectively, the data suggest an improved buffering capacity of the blood after NaHCO3 treatment. However, there was no change in race times or venous partial pressure of carbon dioxide. Therefore, the administration of NaHCO3 provided no ergogenic benefit to horses competing in a 1,600-m race.
Harkins
J D
JD
Department of Veterinary Physiology, Pharmacology and Toxicology, School of Veterinary Medicine, Louisiana State University, Baton Rouge 70803.
Kamerling
S G
SG
D000136:Acid-Base Equilibrium; D000471:Alkalosis / Q000097:blood / Q000503:physiopathology / Q000662:veterinary*; D000818:Animals; D001639:Bicarbonates / Q000097:blood / Q000494:pharmacology*; D001947:Breeding; D002021:Buffers; D002245:Carbon Dioxide / Q000097:blood; D004300:Doping in Sports; D005260:Female; D006734:Horse Diseases / Q000097:blood / Q000503:physiopathology*; D006736:Horses; D006813:Humidity; D006863:Hydrogen-Ion Concentration; D007773:Lactates / Q000097:blood; D008297:Male; D005082:Physical Exertion / Q000187:drug effects*; D012964:Sodium / Q000494:pharmacology*; D017693:Sodium Bicarbonate; D013696:Temperature; D013997:Time Factors; D014919:Wind
D001639:Bicarbonates; D002021:Buffers; D007773:Lactates; D002245:Carbon Dioxide; D017693:Sodium Bicarbonate; D012964:Sodium