The effects of sodium bicarbonate ingestion on cycling performance and acid base balance recovery in acute normobaric hypoxia

Abstract

The effects of sodium bicarbonate ingestion on cycling performance and acid base balance recovery in acute normobaric hypoxia.

Effects of an Alkalizing or Acidizing Diet on High-Intensity Exercise Performance under Normoxic and Hypoxic Conditions in Physically Active Adults: A Randomized, Crossover Trial

“…However, despite an apparent influence of the dietary intervention on acid-base balance parameters and blood buffer capacity, the alkalizing or acidizing diets had no significant effect on PTSR-related performance parameters (PF, MF, and FI), or on the associated physiologic responses of La max and HR. It was previously reported that pre-alkalization prior to exercise had an ergogenic effect for anaerobic exercise performance under normoxic [32,40,42] and hypoxic conditions [32,[35][36][37][43][44][45]. However, whereas NaHCO 3 ingestion is a well-established method for an enhancement of anaerobic performance, the influence of an alkalizing diet on anaerobic exercise performance is still controversially discussed [67] and some investigations reported for less pronounced systemic alkalinity, blood buffer capacity, and an unaffected anaerobic exercise performance after an alkalizing diet [56][57][58].…”

“…By contrast, power output for tests with continuous or repeated high-intensity exercise longer than 45 s, like the 3-min all-out critical power test and repeated sprints, is often reduced in acute hypoxia [20][21][22]24,32]. Therefore, we propose that performance tests assessing for anaerobic, high-intensity exercise performance in hypoxic conditions should last for more than 45 s. A number of studies have also examined the positive effects of supplementation with ergogenic aids such as sodium bicarbonate (NaHCO 3 ) or dietary nitrate as alkalotic buffers for attenuation of the impaired exercise performance under hypoxic conditions [32,[35][36][37][38][39]. Ingestion of NaHCO 3 increases the [HCO 3 − ] concentration in extracellular fluids, which leads to an enhanced buffering of hydrogen ([H + ])…”

“…ions [40,41]. This [HCO 3 − ]-induced increased buffering capacity seems to improve high-intensity exercise performance in normoxia [32,40,42] and hypoxia [32,[35][36][37][43][44][45]. A few studies have examined the effect of NaHCO 3 ingestion on anaerobic exercise performance at altitude.…”

“…Although some studies found no effect of [HCO 3 − ] supplementation on the power output of high-intensity exercise at simulated altitudes of 3000 m and 2500 m [46,47], a constant or improved anaerobic exercise performance at simulated altitude compared with anaerobic exercise performance under normoxic conditions was described for participants receiving alkalizing agent supplements prior to exercise [43][44][45]. In addition, positive effects of NaHCO 3 ingestion under acute moderate normobaric hypoxic conditions during intermittent and repeated high-intensity exercise were reported [32,[35][36][37]. In those studies, the authors concluded that NaHCO 3 ingestion may offer an effective ergogenic strategy to alleviate hypoxia-induced declines in anaerobic exercise performance.…”

“…Overall, these studies suggest that NaHCO 3 ingestion and the associated [HCO 3 − ]-induced enhanced buffering capacity may enhance high-intensity anaerobic exercise performance under acute normobaric hypoxic conditions [32,[35][36][37][43][44][45]. Additionally, several studies propose that an alkalizing diet can change the blood buffer capacity, which influences high-intensity anaerobic exercise performance in a way similar to NaHCO 3 ingestion [48,58,59].…”