“Oxygenated” water and athletic performance
- Correspondence to: Dr Piantadosi Box 3315, Duke University Medical Center, Durham, NC 27710, USA;
- Published Online First 19 July 2006
Ergogenic claims for oxygenated water cannot be taken seriously
A decade or so ago, the idea arose that athletes might gain a competitive edge by drinking water that contained extra dissolved oxygen (O2). The notion stems from observations that O2 breathing during exercise enhances athletic performance,1,2 but the connection of O2 breathing during exercise with drinking “hyperoxygenated” water before exercise conflates physics and physiology in a struthonian visit to placebo land. Fuelled by bottled-water mavens, who collect testimonials for oxygenated waters, claims abound of ergogenic benefits of water advertised to hold up to 40 times more O2 than plain water.
The issue of hydration aside, such claims have a flimsy rationale and no rigorous experimental support. On close inspection, three scientific problems immediately arise. Firstly, for all practical purposes, supplemental O2 improves performance only during exercise, not before or between bouts.3 With normal lungs, breathing of even pure O2 at sea level increases maximal O2 uptake (o2max) by only 5–10% because air breathing alone, except at high intensity work, keeps the arterial O2 saturation (Sao2) and content (Cao2) very high.2
The next problem is that the solubility of O2 in water (and plasma) is low. The solubility constant obeys Henry’s Law: it is directly proportional to O2 …