Friday, October 22, 2010
Is it possible to drink too much water?
In a word, Yes! But you really have to work at it. It takes a lot of water to overdo it, and you have to lose salt from your body as well. Marathon or half-marathon running, all day hiking, 12- or 24-hour adventure races, and all such athletic feats have the potential to deplete your body's salt through all that sweating. You lose salts through your sweat, and if you just drink pure water to replace it, you will eventually achieve "hyponatremia." Hyponatremia is a condition where sodium in your blood falls below normal, and this has some severe effects. Hyponatremia can cause muscle weakness, muscle spasms, dizziness, nausea, vomiting, unconsciousness, headache, confusion, and lethargy. At athletic events, it is easy to confuse these symptoms with heat exhaustion, heat stroke, or plain exhaustion from the physical exertion. It is important for athletes to get a little salt in their body along with the water. Athletes can mix water 50/50 with a sports drink, or eat a salty snack occasionally during the event.
Warning: the Science Lady is about to get all technical on you! Why do we need sodium? There are several salts that our body really needs to function. Sodium is a monovalent cation (+1 charge) that cannot cross the membrane of our cells without the help of an ion channel. Potassium (+1) and calcium (+2) are also cations and need an ion channel for transport. Your heart keeps its regular beating rhythm through the use of calcium ion channels. Calcium is needed for your heart to keep a steady pace! Ion channels allow us to contract and release our muscles, pump needed molecules and nutrients into our cells, feel the sensation of pain, and maintain the correct water volume in our bodies. Too much sodium contributes to high blood pressure, but a little is necessary for a healthy body.
Hey folks, I know you're out there. I need some more Questions!