We are constantly being advised that we should drink about 2 litres of water each day. But did you know that too much water can be bad for you.
Image: FreeDigitalPhotos.net
While dehydration is a common concern for exercisers, some experts think the public should be aware of the danger of drinking too much water. In some cases it can lead to a potentially fatal condition called HYPONATREMIA.
Hyponatremia is characterised by an abnormally low blood concentration of sodium. It is most often seen at extremely high-endurance events such as ultra-marathons.
The normal concentration of sodium in the blood plasma is 136-145 mM. Hyponatremia occurs when sodium falls below 130 mM. Plasma sodium levels of 125 mM or less are dangerous and can result in seizures and coma.
Hyponatremia was responsible for the death of 22 year old David Rogers in the Flora London Marathon in April 2007. David, a fitness instructor, completed the race in 3 hours 50 minutes. He collapsed shortly after he crossed the finish line and had to be rushed to hospital.
Symptoms of moderate hyponatremia include tiredness, disorientation, headache, muscle cramps, and nausea, while severe hyponatremia can lead to seizures and coma.
Research suggests that drinking about two cups of fluid two hours before exercise and another six to eight ounces every 20 minutes can help optimize performance.
How can I tell if I’m properly hydrated?
The simplest way to tell whether you are hydrated or not is to check the colour of your urine. A light yellow/straw colour indicates proper hydration. The darker the urine colour the greater the dehydration level.
For greater accuracy you can compare the colour of your urine against a urine chart. The lower the number, the better the result. A urine color rating of 1, 2 or 3 is considered to be well-hydrated (Armstrong, 2000).