Instead of following a strict plan, it’s better to just listen to our body and drink when we’re thirsty, say researchers from Monash University in Australia. Our brain has a ‘swallowing inhibition’ that stops us drinking when we have had enough—but if we over-ride that and continue drinking, we can even kill ourselves.
The researchers point to several cases of marathon runners who drank too much water before the race and died of water intoxication, or hyponatremia, which happens when sodium levels in the blood become abnormally low as a result, causing lethargy, nausea, convulsions, coma and death.
To test the body’s natural regulator, the researchers asked participants to rate the amount of effort needed to drink water after they were thirsty following exercise, and then again later when they weren’t thirsty. Drinking water when they weren’t thirsty took three times the effort, they found.
But although we don’t need to drink eight glasses a day, we do need to drink enough water, and that’s especially true for older people, the researchers say.