Health experts suggest drinking plenty of fluids during exercise to help avoid dehydration but according to new study, too much water can be very dangerous.
The new study suggests that good hydration is important, but overhydration can be hazardous, even lethal.
Dehydration increases the risk of muscle cramps, heat exhaustion, and heat stroke during exercise in warm weather.
And even in mild weather, dehydration can leave exercisers groggy for hours afterward.
When the risks of dehydration became apparent, experts began to encourage drinking fluids during exercise.
Guidelines were formulated to meet the needs of elite male athletes whose high-intensity exercise produced lots of fluid loss in sweat.
As a result, athletes began to increase fluid intake, and some drank too much, leading to water intoxication and hyponatremia (low blood sodium levels). Hundreds of cases and a number of deaths have been recorded in medical journals.
Harvard Men's Health Watch has suggested that plan to drink two to three cups of water an hour, but boost the amount if sweating heavily.
Unless you get way behind in your fluid replacement, sports drinks won't be any better than water.
Drink when you feel thirsty, but don't force down huge amounts.
In case you gain weight, feel bloated, or experience nausea and vomiting, you're on your way to trouble.
The study is published in the July 2008 issue of Harvard Men's Health Watch.