Just because something is good doesn't always mean that more is better. Yes, most of us could use more water in our daily lives. But too much of a good thing isn't so good. In fact, it can be dangerous.
An excess of water in the system dilutes the amount of sodium in the blood, causing hyponatremia. Endurance athletes are particularly at risk for over-hydration, known as exercise-associated hyponatremia, as extreme thirst can result in drinking too much at once, shocking the system and putting the body in a perilous imbalance. The kidneys get overwhelmed with too much liquid to process at once. And the body's naturally occurring sodium can't keep up with the amount of water, leading to low blood volume and swelling in the cells. (Yes, this could be what makes you feel bloated and - literally - waterlogged).
In a study published by the New England Journal of Medicine, an alarming 13% of runners in the 2002 Boston Marathon were suffering from hyponatremia at the finish of the race. Being over-hydrated is not the way to feel or perform your best - and in very severe cases can be deadly.
Athletes should watch out for the following symptoms that are associated with hyponatremia:
Sip, don't chug. As a rule of thumb, your body can't process more than a liter of liquid per hour. Sip your way through your race or workout and avoid trying to play "catch up" by downing a bottle at once.
Add electrolytes. Adding electrolyte mix to your water (like GQ6 3:2:1 Hydration and/or Endurance) can help prevent hyponatremia.
Do the math. This hydration calculator can help determine the right amount of hydration for you.
Weigh yourself. You can also weigh yourself before and after a workout to make sure you replenish exactly what your body lost through sweat throughout the effort.