Be careful about the amount of water you drink during exercise, say doctors
You keep a bottle of mineral water on your treadmill’s panel and gulp it down after every three kilometres. It keeps you from dehydrating, you think. Stop. Experts now warn that drinking too much water during exercise or any intense physical activity could harm you.
Researchers in the United States studied the blood samples of 488 individuals before and after they ran in the Boston marathon. Sixty-two of them drank an average of three litres of water or a sports drink and developed hyponatremia, a condition where excessive water in the bloodstream creates dangerously low amounts of sodium. Three became very sick. The 62 were the slow runners who took more than four hours to finish the course, obviously taking breaks to drink plenty of liquid.

“Drinking lots of water increases blood plasma which, in turn, decreases the blood’s salt content. If you are consuming a lot of water and also sweating, you can easily lose lots of salt. Consequently, your body will lose the electrolytes that are necessary to keep its brain, heart, and muscles functioning properly,” says Dr S.K. Aggarwal, internal medicine, Indraprastha Apollo Hospitals. Symptoms of hyponatremia include nausea, vomiting, muscle weakness, headaches, and bloating in the face and hands.

Hyponatremia is more common among women athletes than men and was also responsible for the death of a 43-year-old woman who was running in a marathon in the United States a few years ago.
Cases of hyponatremia have been on the rise for the past five years due to the popularity of marathons. “Earlier, only athletes would participate in them. Now, most people who take part are not as competitive and they stop a lot of times to consume water. The more they stop, the more they drink, not realising that what they are doing could be harmful,” says Dr Aggarwal.

... contd.