Did you know that most people are "permanently partially dehydrated", which, according to a Leeds University (UK) study means that "our brains are working considerably below below capacity and potential". The Leeds study discovered that school children who performed best in school were those who regularly drank up to eight glasses of water per day, but given the findings from a battery of other research studies published over the last decade (in such scientific journals such as the International Journal of Psychophysiology, the Journal of the American Dietetic Association, and the Archives of Environmental Health), that's just the tip of the iceberg.
Most of us already know that serious dehydration makes you feel dizzy, light-headed, confused, slow, even hallucinatory. But many don't realize that even mild dehydration, such as the kind that affect so many of us without even realizing it, can seriously impair your mental abilities? We're talking about everything from short-term memory abilities, long-term memory storage and retrieval, math abilities, visual-motor tracking, coordination and perception problems.
How many times have you been out shopping or doing errands for several hours, and forgot to drink anything? Or how about at work, or busy with a household project at home, or traveling? Worse, did you fool yourself by drinking only some coffee or other (generally) dehydrating beverage, got busy and just didn't think that you needed to drink anything else? If you think back to any of these experiences, do you remember how you felt when it had been several hours since you properly hydrated yourself? Probably not well.
Given the very real effects on your brain & body that even mild dehydration causes, this becomes even more relevant when you're doing such things as driving, critical work, creative functions, learning or reading, and so on. Why impair yourself when it's just so incredibly easy to get your brain back and keep it running at full speed, just by drinking enough water, often enough?
Back to the "8 glasses per day" topic again: there's some debate about how much non-pure water beverages (particularly caffeinated ones) "count" towards your daily intake, so why take chances: getting your 8 glasses per day is incredibly easy. The ready availability of water in all of its packaging these days makes it difficult to not be in a place where there's some form of bottled, drinking fountain or (decent) tap water available. If you try to spread out your eight glasses throughout the day, such as a glass every couple hours on average between morning and evening, you'll be sure to be well-hydrated throughout your waking hours.
If you exercise (which you should if you are able, by the way, ideally every day) or are in a hot or very dry environment, however, you'll want to increase your intake accordingly, particularly BEFORE exercise or sweating a lot under hot conditions, as once you already feel the effects of dehydration coming on, it's much more difficult to get your brain back into full performance mode again (it takes some time for your brain to absorb and "realize" that you're hydrated again) compared to just not getting dehydrated in the first place by properly hydrating beforehand.
So, no more excuses: now you have another reason to get those 8 glasses of water per day...allowing your brain to function as well as it's capable of, instead of hindered by something so easily avoided.