Anything in excess is bad. May it be food, sleep, tv, and many others. This does not exclude water (and other fluid) intake, especially during physically intense activities such as marathons.

     Drinking too much fluid will cause a possibly fatal condition called Hyponatermia. Hyponatermia happens when there is not enough sodium in our body fluids. Its symptoms may include confusions, hallucinations, nausea, vomiting, cramps or fatigue.

     To avoid hyponaternia, the International Marathon Medical Director’s Association (IMMDA) recommends drinking only when thirsty. They also recommend drinking sports drinks instead of water when running for more than 30 minutes. The inclusion of carbohydrate and electrolytes in sports drinks speed up the rate at which the body absorbs fluids. They also discourage diluting sports drinks with water as it decreases its effectiveness.

     Too little fluid intake is also bad. One should have just enough intake to suite our body’s needs. IMMA recommends an average of a liter of fluid an hour if you run a mile in 8 minutes, 750 ml per hour if you run at a rate of a mile in 9 minutes, 500 ml per hour if you run a mile in 10.





Sources:
http://aimsworldrunning.org/guidelines_fluid_replacement.htm
http://www.nlm.nih.gov/medlineplus/ency/article/000394.htm
http://www.sciencedaily.com/releases/2011/09/110903133240.htm
Photo by Greg Riegler flickr.com