For athletes, the risk of too much water
By Gretchen Reynolds, New York Times
Are we, with the best of intentions, putting young athletes at risk when we urge them to drink lots of fluids during steamy sports practices and games?
A report about overhydration in sports suggests that under certain circumstances the answer is yes, and that the consequences for young athletes can be — and in several tragic cases already have been — severe and even fatal.
According to the latest science, dehydration during sports is rarely if ever dangerous, but overhydration undeniably is.
Hyponatremia occurs when someone consumes so much fluid that his or her body can’t rid itself of the surplus through sweating or urination. As a result, water levels rise in the bloodstream and sodium levels, diluted, fall. Osmosis then draws water from the blood into the surrounding cells of the body to equalize sodium levels there, and those cells begin to swell like water balloons. If this process occurs in the brain, it can be lethal.