Abstract
The effects of NaHCO3 ingestion on cycling performance in seven 30-second Wingate Anaerobic Tests separated by 4.5-minute intervals was studied in six male ice hockey players. Subjects ingested either 0.2g/kg (body weight) of NaHCO3 or control (1g of NaCl) drink 1 hour before exercise. During each 30-second exercise bout, flywheel revolutions were electronically recorded, and mean power and peak power outputs were calculated. Blood samples taken from the antecubital vein revealed that the intake of NaHCO3 increased resting pH (7.37 to 7.42) and HCO3- (29.8 to 32.5 mM) . During and after exercise blood pH and HCO3- tended to be higher in NaHCO3 trials than in control trials. Mean power output during the entire exercise period was significantly higher (p<0.001) in the NaHCO3 trial (7.70±0.28 W/kg) than in the control trial (7.10±0.60 W/kg) . Also in the NaHCO3 trial, mean power output and peak power output were significantly higher (p<0.05) during the 4th, 6th and 7th exercise bouts, and during the 5th to 7th exercise bouts, respectively. Furthermore, the ΔHCO3- and the Δmean power output in each subject were significantly correlated (p<0.05) . Also, the decrease in pH or HCO3- and the decrease in mean power output were significantly correlated (p<0.001) . These relations were exponential rather than linear, so the decrease in pH and in HCO3- in blood accelerated the decrease in mean power output. Thus, we conclude that ingestion of NaHCO3 before exercise facilitates the buffering capacity for acids in blood during exercise, and thereby has an ergogenic benefit for supramaximal intermittent exercise.
