Effects of induced alkalosis on simulated match performance in elite female water polo players

Int J Sport Nutr Exerc Metab. 2010 Jun;20(3):198-205. doi: 10.1123/ijsnem.20.3.198.


This study investigated the effects of sodium bicarbonate (NaHCO3) ingestion on simulated water polo match performance. Twelve elite players from the Australian National Women's Water Polo Squad (age 23.7 +/- 3.0 yr, height 1.73 +/- 0.05 m, body mass 75.7 +/- 8.0 kg) participated in the study. In a randomized cross-over double-blind design, players ingested 0.3 g/kg of NaHCO3 or placebo 90 min before performing a 59-min match-simulation test (MST) that included 56 x 10-m maximal-sprint swims as the performance measure. Capillary blood samples were obtained preingestion, pre- and post-warm-up, and after each quarter of the MST. Preexercise ingestion of NaHCO3 was effective in enhancing extracellular pH from baseline levels of 7.41; +/- 0.01 (M; +/- 90% confidence limits) to 7.49; +/- 0.01 and bicarbonate levels from 24.4; +/- 0.3 to 28.5; +/- 0.5 mmol/L. The percentage difference in mean sprint times between trials showed no substantial effects of NaHCO3 (0.4; +/- 1.0, effect size = 0.09; +/- 0.23; p = .51). These findings are contrary to those of previous NaHCO3 studies on simulated team-sport performance, but this investigation is unique in that it examined highly trained athletes performing sport-specific tasks. In conclusion, water polo players should not expect substantial enhancement in intermittent-sprint performance from NaHCO3 supplementation.

Publication types

  • Randomized Controlled Trial

MeSH terms

  • Alkalosis / chemically induced
  • Alkalosis / physiopathology*
  • Athletic Performance
  • Cross-Over Studies
  • Double-Blind Method
  • Female
  • Humans
  • Hydrogen-Ion Concentration
  • Oxygen Consumption / physiology
  • Sodium Bicarbonate / pharmacology*
  • Swimming / physiology*
  • Task Performance and Analysis
  • Young Adult


  • Sodium Bicarbonate