Sodium bicarbonate ingestion does not alter the slow component of oxygen uptake kinetics in professional cyclists

We examined the effects of pre-exercise sodium bicarbonate (NaHCO(3)) ingestion on the slow component of oxygen uptake ((V)over dotO(2)) kinetics in seven professional road cyclists during intense exercise. One hour after ingesting either a placebo or NaHCO (0.3 g.kg body mass(-1)), each cyclist (age, 25 +/- 2 years; (V)over dotO(2max), 74.7 +/- 5.9 ml.kg(-1).min(-1); mean+/-s) performed two bouts of 6 min duration at an intensity of 90% (V)over dotO(2max) interspersed by 8 min of active recovery. Gas exchange and blood data (pH, blood lactate concentration and [HCO(3)(-)]) were collected during the tests. In both bouts, the slow component of (V)over dotO(2) was defined as the difference between end-exercise (V)over dotO(2) and the (V)over dotO(2) at the end of the third minute. No significant difference was found in the slow component of (V)over dotO(2) between conditions in the first (NaHCO(3), 210 +/- 69 ml; placebo, 239 +/- 105 ml) or second trial (NaHCO(3), 123 +/- 88 ml; placebo, 197 +/- 101 ml). In conclusion, pre-exercise NaHCO(3) ingestion did not significantly attenuate the (V)over dotO(2) slow component of professional road cyclists during high-intensity exercise.