Since elementary school, most of us have been beaten over the head with the notion that eight glasses of water a day is enough to stay hydrated.
This notion, however, is plain wrong. Water makes up more than 60 percent of your body 
weight, and every single internal system in your body relies on water to work properly. Every day, water is responsible for the vital tasks that keep your body running properly: e.g. flushing toxins and waste out of internal organs (and eventually out of the body altogether), regulating body temperature, hauling minerals and nutrients to your cells, and creating a moist environment for ear, nose, throat and other sinus related surfaces.
Knowing all this, do you really think a measly eight glasses of water is adequate? Well, the answer should be a resounding “no.”
So how much is enough? It depends on the individual. According to a recent article published in U.S. News & World Report, “The basic equation for determining this is by dividing your body weight in half. If you weigh 200 pounds, you would need 100 ounces of water per day if you’re not doing anything strenuous. If you’re working out, hiking, at a high altitude or outdoors a great deal, you’re going to need to add to those 100 ounces.”
Moreover, in a joint study from the Department of Health and many others, seniors are apparently at a much greater risk of dehydration than the rest of the population. According to the study, dehydration may be responsible for a spike in mortality rates among older adults as well as an increase in emergency hospitalizations. It is actually among the top 10 most frequent reasons for hospitalization among U.S. seniors. And dehydration has also been linked to “elderly confusion, impaired cognition, falling and constipation.” What’s more, a recent University of Chicago Medical Center study found that people over 65 account for 40 percent of dehydration and heat-related deaths in the U.S.
So, yeah, that’s A LOT more than 8 glasses of water. And what happens to your body if you don’t happen to get this much water?
The U.S. News article also outlines what’s at risk when a person isn’t hydrated: “When you don’t get enough water, every cell of your body is affected. When you sweat, you lose a lot of electrolytes, including sodium, potassium and chloride, which are essential to your body’s functions. Pretty much all of your cellular communications revolve around sodium and potassium, including muscle contractions and action potentials… Fatigue, lethargy, headaches, inability to focus, dizziness and lack of strength are all possible signs of dehydration. When in doubt about the reason for these symptoms, go ahead and down a glass or bottle of water.”
Even if you’re not sweating or exerting yourself right at this moment, you are still losing water… right at this moment! Water is leaving your body by way of your breath and imperceptible sweat drops on your skin. And according to a brand new study by the CDC, the odds are pretty good (about 50/50) that you’re not drinking enough water.
So, after you finish that last sip of your glass of water today, go ahead and fill it up again… because you probably need it.