Saturday, February 9, 2008

Hydration

Literally every single cell in your body contains water. In fact most cells - besides fat cells - comprise more water than other solid materials. There is an occasional debate between scientists and doctors as to how much of your body weight is water - some say about 65% others give numbers up to 85% - but either way it is a lot. A 185 pound man holds about 120 pounds of water! A popular TV show once called humans “ugly bags of mostly water”. I don’t agree with the ugly part, but we certainly are mostly water.

As it turns out, water is a very active molecule. Science bases much of its points of reference on the properties of water. Compared to other molecular compounds, water is transferred from solid to liquid to gas fairly easily. Because water is so productive, however, it constantly needs to be cycled within our body. The cycle is simply the regular intake, decomposition, and expulsion of the H2O water molecule. Remember, water is in every single cell in your body, but each cell may use that water a little differently.

Interestingly, water is actually a waste product of a variety of chemical processes in the body as well as a nutrient and source of energy. With all this water moving around inside of you, your body has also evolved in such a manner that makes it very good at releasing this molecule into the air. You continuously excrete water through your skin - albeit slowly - and as we all know, if your body temperature rises, you release a combination of water and electrolytes called sweat. Every time you breathe, blow your nose, or make that trip to the rest room, you are releasing water. You body doesn’t have any direct means of putting that water back, however, at least not without some conscious action from you.

It is very easy to take in water. Because there is water in every living thing, each time you eat or drink anything, you get a little water in you. Usually, if something is in liquid form such that it is drinkable, it is because that substance is full of water so drinking, as you would expect, is the best way to replace water. Drinking pure water is the best way to ensure that your body can do with your new hydration what it likes as well. If you drink something - fruit juice, soda, alcohol - that contains some flavoring or other components other than the basic water, those components have to be digested and used like anything else. Your body actually measures its necessity for nutrients and food based upon the balance that exists between various essential minerals and electrolytes and water. If you have too much water, your body will simply tell you to go to the rest room. If you have too little, you will feel thirsty. Oddly enough, though, over time our sensory perception of thirsty has become muddled a little bit. Sometimes the sensation of thirst can be confused with the sensation of hunger so instead of drinking something, we eat something - forcing our body to use water to digest - making us more thirsty. It is sort of a goofy conundrum.

In order to digest just about anything your body combines the food with water and flushes it out of your system. If you drink a soda which is loaded with water, sugar (even fake sugar) and caffeine, you’ll actually have to release the water in order to digest the other substances. The same is true for fruit juice, although some of the substances found in fruit juice are helpful in their own right. Alcohol actually goes beyond the regular combining process for digestion and attracts extra water, forcing your body to release even more of it’s hydration that it typically might. It is, therefore, important that we drink pure water frequently - several times a day. This is not to say that we shouldn’t indulge in juice, soda or even alcohol, but you aren’t helping your body as much as you can if these are the only substances you are willing to drink.

So how much water do we need? Basic health information dictates that we should drink eight, eight ounce glasses of water a day at minimum. An eight ounce glass of water is only the volume of one cup so it’s not that hard to get this amount of water into yourself at one sitting. If you are active, you are probably creating sweat and increasing your breathing meaning you need to replace more water. If you are consistently active, look to taking in 12 to 15 eight ounce glasses of water per day. Carrying a water bottle around with you and taking frequent sips or gulps is a great way to constantly hydrate yourself. Most individual size water bottles contain between 12 and 16 ounces. If you manage to drink the water contents of that bottle five or six times in a day, you’ve got plenty of water in your system (remember that you will take in water from other sources as well).

You can actually tell if you are drinking enough water each time you go to the rest room. If your urine is clear, it means that your body is releasing more water than other nutrients and, therefore, has plenty of water to keep itself going. If, however, your urine is a dark shade of yellow, your body is actually releasing nutrients in an effort to hold onto water in your system. These nutrients could have been used if you had enough hydration to handle them, but your body needs to conserve water so do it a favor - drink a glass or two. The exception to this indicator occurs if you take vitamins of some sort. Usually vitamins contain much more of a particular compound than your body needs at that moment so it will use what it can and release the rest, causing your urine to be a bright yellow. If you are taking a vitamin and drinking enough water, this yellow excretion should only happen once a day within a few hours of taking the vitamin.

Because your body operates on a balance of nutrients and water, we can assume that proper hydration is also a function of correct amounts of elements like sodium, potassium and other electrolytes in your system. This balance is the reason we now have sports drinks. The creators of these drinks recognized that a highly active person will lose significant amounts of nutrients along with water loss when they sweat and consume energy. Sports drinks contain elements like potassium, sodium, sugars and occasionally other vitamins and minerals which may aid the body in recovery of worn tissues and lost energy. The key to the purpose of these drinks, however, is for whom they were designed - highly active people. There is a lot of sugar in sports drinks. It is put there intentionally to replace lost energy as a highly active person is exerting work. These sugars are simple and quickly absorbed into the body and, if you are working very hard, quickly used as energy. If you are not a highly active person and if you are not engaging in extreme activity at the time you take a drink, there is no reason to need a sports drink.

Also, sports drinks are often very concentrated when bought off the shelf both to replenish nutrients lost from highly active athletes and for taste. Ultimately there is too much sugar in these drinks for the average person or even the average workout. I as a personal trainer who engages in very difficult workouts, wont consume a sports drink at its full concentration. Certainly the electrolytes in these drinks help during a workout so one way to get those nutrients and some of the energy necessary to complete your exercise is to cut the regular concentration of the drink with water. Pour out and save half of your regular sports drink, then refill the bottle with water. At this concentration you will have plenty of electrolyte replenishment for your workout without excess sugar.

Believe it or not, it is possible to drink too much water. This rare condition occurs when the body contains so much water relative to its accessible electrolytes that it literally shuts down because there ceases to be proper nutrient passage between cells. Hyper-hydration or the excess of water in balance to electrolytes is very dangerous and frequently fatal, however it is a condition which is very difficult to achieve. If you are a very long endurance athlete like a marathoner, distance triathlete, ironman/woman, or other extreme distance competitor you may need to consider hyper-hydration. Because your body releases electrolytes in sweat, if, during your extended activity (over the course of several hours) you only replenish yourself with water, you have a chance to create this imbalance. If you are in an organized even, the organizers are usually aware of this problem and will offer more than just water at check-stops. Now you’ll find sports drinks, energy bars, fruit, and even gummy bears to replenish the sugars in your body as well as the water. These other items can be helpful in maintaining the balance in your system. Another way to induce hyper-hydration is simply to drink too much water at one time without allowing your body to release it. You’d have to drink water at a magnitude of several gallons in an hour to achieve this level of imbalance. No one is ever that thirsty, and you stomach would be painfully full before you manage to drink too much. A radio contestant once managed to drink so much water as to induce hyper-hydration, but this was a contest and essentially no one does this on their own.

So even with water - as anything - going overboard can be detrimental to your body. Fortunately water is one of the main driving forces of life as we know it so too much water is a condition very difficult to achieve. Too little water, however, is frequently a problem afflicting many people in regular life. You need to make sure your body is getting plenty of pure water every day - to keep you systems running properly, for nutrition, and even to ward off infection. Just remember, at least 8, 8 ounce glasses per day and more than that if you are going to do anything active. Make sure that your body remains “mostly water”.

1 comment:

Janet said...

Hey maybe my jelly belly is mostly water! I guess I shouldn't hydrate with wine then.

Interesting about the shade of urine. I thought if the urine was dark it meant you didn't have enough water to pee out; not that your body was trying to hold on to what it has.

Very scientific and informative blog. Good to know there is a personal trainer that actually knows the science behind training.

Can you write something about that cortisol stuff you mentioned today?