Anaerobic work and power output during cycle ergometer exercise: Effects of bicarbonate loading

Abstract

Eight trained male cyclists who competed regularly in track races, were studied under control, alkalotic (NaHCO3) and placebo (CaCO3) conditions in a laboratory setting to study the effect of orally induced metabolic alkalosis on 60 s anaerobic work and power output on a bicycle ergometer. Basal, pre- and post-exercise blood samples in the three conditions were analysed for pH, pCO2, pO2, bicarbonate, base excess and lactate. All blood gas measurements were within normal limits at basal levels. There were significant differences in the amount of work produced, and in the maximal power output produced by the cyclists in the experimental condition when compared to the control and placebo conditions (P less than 0.01). The post-exercise pH decreased in all three conditions (P less than 0.05) and post-exercise pCO2 increased significantly in the alkalosis trial (P less than 0.01). In the alkalotic condition, the pre-exercise base excess and HCO3- levels were both higher (P less than 0.05) than the basal levels, suggesting that the bicarbonate ingestion had a significant increase in the buffering ability of the blood. Post-exercise lactate levels were significantly higher (P less than 0.05) after the alkalotic trial when compared to the other two conditions, immediately post-exercise and for the next 3 min. Post-exercise lactate levels were higher than basal or pre-exercise levels (P less than 0.001). This was true immediately post-exercise and for the next 5 min. The results of this study suggest that NaHCO3 is an effective ergogenic aid when used for typically anaerobic exercise as used in this experiment. We feel that this ergogenic property is probably due to the accelerated efflux of H+ ions from the muscle tissue due to increased extracellular bicarbonate buffering.

Effect of Combined β-Alanine and SodiumBicarbonate Supplementation on Cycling Performance

“…Acute supplementation of NaHC03 before the 4-min cycling performance trial significantly increased average power by 3.1% (PSB) and 3.3% (BASB) compared with baseline perfonnance. This finding is similar to previous studies that have reported exercise performance improvements after NaHC03 ingestion before sport-specifrc performance in highly trained athletes (5,26,27). For example, NaHC03 supplementation has been associated with ~3% improvements in 400-m (13), 800-m (36), and 1500-m (5) mnning times in middle-and long-distance mnners.…”

“…McNaughton and Cedaro (26) also reported a ~3% improvement in a maximal 6-min rowing ergometer test after a similar dose of NaHC03 in highly trained rowers. For trained cyclists, previous research has indicated that acute NaHC03 supplementation can significantly improve total work done (+6.6%) in a l-min maximal cycling effort (27). The likely mechanism for the improved exercise perfonnance in the current study may have been due to the increased buffering capacity.…”

Sodium bicarbonate can be used as an ergogenic aid in high-intensity, competitive cycle ergometry of 1 h duration

“…The results of such work generally ®nd a positive ergogenic bene®t within the time periods of 1 min to 6 min (Bouissou et al 1988;Costill et al 1984;Gold®nch et al 1988;Jones et al 1977;McNaughton 1992b;McNaughton and Cedaro 1991b;McNaughton et al 1991;Sutton et al 1976;Wijnen et al 1984;Wilkes et al 1983). However, there has been little work undertaken to determine its eects on high-intensity, aerobic-type activity.…”

Effect of voluntary hypocapnic hyperventilation on the metabolic response during Wingate anaerobic test

“…Such alkalosis could potentially improve exercise performance by alleviating acidosis triggered by the strenuous exercise, although whether acidosis contributes to fatigue during intense exercise is still controversial (see other papers for details) (Cairns 2006;Lindinger 2007;Westerblad et al 2002). As pertains to this, reports show that supramaximal exercise performance lasting ~60 s was improved by alkalosis induced by bicarbonate (pH increases by ~0.10) (Douroudos et al 2006;Goldfinch et al 1988;Inbar et al 1983;McNaughton et al 1991;McNaughton 1992), but other studies could not confirm this effect (Kindermann et al 1977;McCartney et al 1983). Importantly, another study showed that acute alkalosis induced by voluntary hyperventilation does not affect power output measured during a 45-s WAnT (Morrow et al 1988), which is consistent with our finding in the present study.…”