Sports doctors all agree: athletes need to drink plenty of liquid during exercise. However, following the death of a female marathon runner who showed abnormally low blood sodium levels because of being over-hydrated, they are now beginning to question this. The marathoner had consumed large amounts of liquid before, during and after competing in her marathon and succumbed to a form of encephalopathy, because the sodium level in her blood was too low.
Writing in the British Medical Journal, South African professor Timothy Noakes reports a number of similar cases observed in athletes, but also in the military on operations and in long-distance hikers. The latter appear to have lost substantial amounts of sodium after consuming large quantities of water or other forms of drink. Sodium is essential to the body as it promotes the movement of liquid from the stomach to the intestines.
Therefore, the recommended amount of liquid a sportsperson should consume during exercise remains to be seen. Without getting into figures, Professor Noakes simply suggests that we should drink according to how thirsty we feel. We should not force ourselves to drink more than we want, and we should drink during and after competing rather than before.
To avoid sodium loss, you can add a salt tablet to your drink. The big advantage of this is, the water will not taste salty. Salt tablets are available from most pharmacies. Staying well hydrated during exercise is essential because, contrary to popular opinion, drinking will not make your legs feel weak, nor make your body heavier.