Sodium bicarbonate supplementation minimally affects the accumulated oxygen deficit during intense cycling to exhaustion

The aim of this investigation was to test whether sodium bicarbonate (NaHCO3) affects the anaerobic energy contribution during a high-intensity cycling task. Eight participants (mean ± SD; age 25 ± 4 years) completed 4 different testing sessions separated by at least 48 hours. During the first 2 sessions, participants performed a series of intermittent bouts of 5 minutes submaximal steady-state cycling and responses were used to calculate the VO2-power regression and estimate the O2 demand of high-intensity cycling. In the final 2 sessions under either a control (PLA = 0.3 g·kg-1 body mass calcium carbonate) or experimental condition (ALK = 0.3 g·kg-1 body mass NaHCO3), participants cycled at 125% VO2peak to volitional exhaustion during which VO2 was measured and the accumulated O2 uptake and O2 deficit were estimated. Times to volitional exhaustion during high-intensity cycling did not differ significantly between ALK (101.3 ± 20.2 seconds) and PLA (98.7 ± 21.4 seconds), and alkalosis did not significantly affect the AOD (ALK: 44.8 ± 10.8 mL·kg-1) and PLA (44.2 ± 12.8 mL·kg-1; P = .82). As such, we would conclude that anaerobic capacity during short-term, high-intensity exercise is minimally affected by metabolic alkalosis induced by NaHCO3 supplementation