Dehydration or hyponatremia?
Friday, Jul 29, 2011
Which is more dangerous, dehydration or hyponatremia? Who has even heard of hyponatremia?
It is summer. It is hot! You like to run. You like to do outdoor activities. After all, that is what summer in Maine is all about. You sweat a lot. You see ads everywhere for beverages to purchase to prevent dehydration. If you sweat, you will lose vital nutrients. You could suffer severely from dehydration, and even die. So, you buy expensive beverages to replenish your electrolytes.
But, should you?
Hyponatremia is a physical state caused by drinking too many fluids, so that the body's salt stores become overly diluted. This can lead to confusion, coma, seizures, and even death.
Every year several athletes die from hyponatremia. Yet in all the years that physicians have been caring for athletes, and this must mean many millions of athletes, there is no record that any athlete has ever died from dehydration.
The tragedy of the deaths from hyponatremia is that they could all have been easily prevented. These athletes literally drank themselves to sickness, because they thought they were preventing dehydration. Studies have shown that there is no performance or health benefit from drinking fluids during endurance events lasting less than about an hour. This means that most runners would not need to rehydrate at all during a 5K road race. These studies show that most athletes drink enough after their workouts to replenish all lost fluids. If an athlete drinks when thirsty, he/she will sufficiently rehydrate.
So, if you like to run road races, or be very active, don't worry too much about dehydration. If you drink when you are thirsty, you will be fine. Drinking too much fluid could be dangerous.