I don’t think anyone out there will try and tell you that drinking water isn’t important for your health. The human body is about 60% water so staying hydrated is definitely good for you. It helps you feel full, it helps fight lethargy, and it keeps your body’s internal processes working smoothly.
But just how important is water? Is it as important as we’re made to believe? Below are 5 common myths about the water and some information about why they’re just not true.
Myth No. 1: Drink Eight Glasses Each Day–This myth is the most prevalent of all the water myths out there yet no one knows just where it came from. So what is the rule of thumb about how much water you need? It’s pretty simple actually: Experts say that if you’re thirsty, you should drink. Except in extreme cases, you probably aren’t drinking too much water–so drink up.
Myth No. 2: Drinking Lots of Water Helps Clear Out Toxins–Most people know that the kidneys are responsible for filtering out toxins from the blood stream. Then, those toxins are excreted in the urine. But does drinking extra amounts of water help the kidneys function more effectively? Most experts say no. In fact, some say that just the opposite is true–that drinking too much water hinders the kidneys’ ability to filter toxins from the blood. But again, the chances of you drinking too much and reducing your kidneys’ effectiveness are pretty remote.
Myth No. 3: Lots of Water Equals Healthier Skin–Some studies suggest that drinking extra water increases blood flow in the capillaries of your skin. But no one is sure if that’s a good thing or not. Think of it another way. If you weigh 180 pounds, about 108 pounds of you is water. How much more water do you think you’d need to drink in order to affect your skin? Drinking an extra glass or two of water would be like adding a grain of sand to a beach, or a drop of water to the ocean. It’s just not going to matter very much.
Myth No. 4: Drinking Extra Water Leads to Weight Loss–Nothing about drinking extra water leads to weight loss. It’s definitely true that drinking water is a useful tool to those of us who are trying to lose weight. The mere act of putting something in our mouths can be helpful. Also, drinking water adds volume to our stomach, making us feel full without actually increasing our caloric intake for the day. Some people would say that other zero calorie beverages can be just as beneficial as water. I don’t agree, but that’s a different article.
Myth No. 5: It’s Easy to Get Dehydrated During a Workout–I love to drink water when I work out. And I’ve only recently made this discovery. But if I’m on the treadmill without water, I feel sluggish and tired. As soon as I take a sip, I feel much better: as if I could run forever. But the fact is that these feelings are all in my head. I don’t feel sluggish because I’m dehydrated. The clinical definition of “dehydration” means a 2% reduction of body weight due to water loss. For me, that’s 3.6 pounds of water in 1 workout. I’ve never been dehydrated in my life because of exercise. But water makes me feel good when I workout, so I’ll keep drinking it.
We’ve all been taught that drinking water is good for us. There’s no denying that this is true. But it’s also true that many of the reasons we’re told that it’s good for us simply aren’t true. From a dieter’s perspective, water is definitely the best liquid to keep us hydrated. It’s all natural, contains no calories, fills us up, and is the original cellular hydrator. So just because some of these “facts” have recently been debunked, don’t give up on water. And remember, it’s never a good thing to drink your calories–milk excluded in my humble opinion.
The information used in this post was furnished by an NPR article from April of 2008.
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I could not disagree more about there being no benefits to drinking increased amounts of water but it works best when done in conjunction to a sauna or salt bath regiment.
I don’t know about drinking lots of water to help flush toxins out of your kidneys, but getting plenty of fluids is a good way to prevent kidney stones! If you’re not getting enough fluids, things can crystalize in your kidneys rather than being flushed out.
There is some physiological basis to a minimum volume of water, and to that helping weight loss. Basically, in order to effectively metabolize fat you need a lot of water – it’s a chemical reaction thing and I don’t have the calculations in front of me. So if you are below the amount of water you need to burn the fat, you won’t be as effective at metabolizing it. All that being said – that is based around the idea of using activities of daily life rather than focused exercise to burn calories. Does that mean that if you drink gallons a day you’ll burn more? Nope, but if you’re drinking too little (which is all based on body size and metabolic rate) you will burn with lower efficiency.
A couple more goodies about water:
1) A glass of ice water is not only calorie-free, it actually BURNS about 10 kcal, as your body heats it up. I got this fact from “Why we eat more than we think” – a pretty interesting book from a food science professor.
2) Re: water flushing out toxins – as you mentioned, the kidneys filter out the toxins, but the water (in urine) is the vehicle for removing toxins from your body. The reality behind “water cleans out your system” is that a more dilute toxin (think poison) mixture is easier for your body to handle. I.e., concentrated urine holds more filtered-out toxins and imposes a greater burden on your “storage tank” (your bladder). Dilute urine fills your bladder more quickly and forces you to empty this poison tank. I’m afraid I’m not saying this very clearly, but the take-away point is that concentrated urine increases the risk of bladder cancer (from toxins sitting around in your bladder longer), and being well hydrated decreases the risk because you empty your bladder more often. (On a side note, peeing infrequently also seems to be related to incontinence later in life.)
3) It takes about 20 minutes for water you drink to be absorbed – so your feeling of relief after drinking is psychological. And I’ve managed to get dehydrated during a workout – it feels like a really bad hangover (unsurprisingly, since hangovers are caused in large part by dehydration).
4) I’ve read that to be well-hydrated, you’ll need to use the restroom every 15 minutes. That would be such a hindrance in a workday that I’m sure almost no one actually achieves this state. I agree that it is unlikely that anyone will become over-hydrated.
Sorry for the long post; it seems I remembered more fun facts about water than I had expected!
Hello: great post.
Please note in regard to Trini’s comment, the vast majority of the toxins that cause bladder cancer are either in cigarette smoke or are industrial exposures (such as industrial dyes), so if you are a nonsmoker, non- factory worker, it is unlikely that you have these toxins in your urine and need to worry about this, and obviously quitting smoking or eliminating industrial chemical exposure would be a better cancer prevention strategy.
My field is emergency medicine, but in medical school I rotated with a urogynecologist and she recommended urinating about 6-8 times daily which seems pretty doable, obviously you want to drink more water if you are losing a lot through sweating. I don’t think anyone needs to aim for every 15 minutes, you’d have to have a constant Camelbak!
By the way, clinically, we doctors do not measure the amount of water lost to determine dehydration. We make that diagnosis based on physical findings such as decreased urination, thirst, dry mouth and other mucous membranes. In babies we look for sunken fontanelles, dry diapers, and crying with no tears. If you have these symptoms, you are probably dehydrated and need to get some fluid in yourself! You don’t have to estimate your sweat output.
It is actually quite common to get dehydrated when working out on a hot day, and it’s a common reason why we see people in the emergency department when they get dizzy or suffer from heat cramps, heat exhaustion or even heat stroke. To avoid these things, stay well hydrated at all times and if it is a hot day, don’t strenuously exercise outside for too long without taking a break in an air conditioned setting. Heat exhaustion usually only requires fluids to correct electrolyte abnormalities, but heat stroke is a very serious form of heat illness that can cause you to require admission to the hospital. I especially have seen teenagers who play organized sports like football suffer from this and it can even result in death in extreme cases, I am sure everyone has heard a tale of some military recruit or football player or something who collapsed on the field because they were doing strenuous exercise in weather that was too hot, with too little water.
Quinsy, thanks for the clarification. I had read about the link between toxins, dehydration, and bladder cancer in an article about how smoking is bad for you – so of course you’re dead on and that makes sense. It seems I had mentally broadened this risk into a general issue, rather than one specific to smoking, and I apologize for the misinformation. Ironically, I work in cancer research, but luckily I’m not in charge of any of the scientific work!
As a side note, I probably hit the bathroom 12 times a day on average. I do drink throughout the day, but pretty much only in response to or to ward off thirst. I categorize thirst as the actual dry mouth feeling, but before I hit that stage I usually feel uncomfortably hot (kinda clammy sweaty), irritable, and light-headed. Normal, abnormal?
I love to drink cold water! My kids see me drink throughout the day and so they also choose to drink water as their “go to” beverage.
Hey Mac! Great article
There are so many myths out there around water consumption…
As a nutrition (almost) professional, the general teaching on water consumption is 2L / day for women and 2.5L / day for men. However, the best indicator is urine color… If when you pee, your urine is very light yellow to clear, you’re generally (at least at the moment) well hydrated. The darker the urine, the more dehydrated. Dark yellow is not good.
Also, on cold water, there is research coming out that ice cold water actually slightly numbs the stomach, thus causing the drinker to eat more!! Warm water is actually better for everything, including your teeth.