How Much Water is Enough?
We’ve all heard the old saying:
Drink eight 8 oz glasses of water a day.
But recent research has shown that this is an arbitrary number and that eight glasses of water a day isn’t really necessary.
Or is it?
There are a lot of factors to consider when trying to figure out how much water or fluids you need to drink on a daily basis.
If you go online and search for the answer to the water questions, you’ll get a variety of different answers. For example, the Mayo Clinic website states (in a nutshell) that you need to take into account all of the fluids you drink on a daily basis plus how much you exercise and how many fruits and vegetables you eat (most of which contain 80-90 percent water). You also have to consider where you live (the type of climate) and your current weight/size.
WebMD says essentially the same thing, but goes on to suggest that one should drink about .5 oz to 1 oz for each pound of body weight. So an individual weighing 205lbs (such as myself) should drink 102.5 oz to 205 oz of water a day (give or take).
However, after 21 years in the medical field, I’ve found there are quite a few more factors to consider when trying to determine how much water your body needs on a daily basis.
Yes, you should consider your current weight, activity level and location as well as your current level of fluid intake and dietary consumption of fruits and veggies. But there are a number of other things you need to consider including:
- Frequency and intensity of exercise.
- Any supplements you may take.
- Any medications you may take.
- Other beverages you consume (including coffee, tea etc.).
- Health Conditions (diabetes, high blood pressure, Sjogren’s syndrome)
Let’s look at each of these individually.
Frequency and Intensity of Exercise
Hopefully, when you workout, you get a good sweat. That means you’re challenging your body. But it also means you’re using up your water reserves and need to replenish them.
If you exercise on a daily basis, you’ll need to drink extra water before, during and after each workout, to compensate.
But you also need to consider intensity. For example, if you’re a marathon runner, you probably should drink a sports drink like Gatorade, that contains sodium so that you also replenish your electrolytes as well as your fluids.
Many people don’t consider supplements important, but they are. While they aren’t as dangerous as prescription medications, they still have an effect on the body and affect your fluid levels. For example, vitamin C is a diuretic, meaning it forces the kidneys to produce more urine, which rids the body of excess fluid. This means you’ll need to drink more water to compensate for the extra fluid loss.
There are so many prescription medications that affect the body’s water levels, albeit not as dramatically as exercise. These include:
- Diuretics (including but not limited to hydrochlorothiazide, triamterene, furosemide, bumetanide, spironolactone, methazolamide, neptazane, acetazolamide)
- Opiate Pain Killers (hydrocodone, tramadol)
- ACE inhibitors (enalapril, verapamil)
- Beta Blockers (metoprolol, atenolol, bisoprolol)
- Alpha Blockers (terazosin, doxazosin)
- Angiotensin Receptor Blockers (losartan, valsartan)
- Alpha agonists (clonidine, methyldopa)
- Direct Renin Inhibitors (Tekturna)
- NSAIDs (ibuprofen, naproxen, diclofenac, ketorolac)
The above list is not exhaustive, but it does include some of the most commonly prescribed medications that affect water balance. All of the above medications, with the exception of the opiate pain killers, affect kidney function either by decreasing kidney function (as in the NSAIDs and beta blockers) which means you’ll need less water, or increasing kidney function (as in the diuretics) which means you’ll need more water.
The opiate painkillers such as hydrocodone, oxycodone, and even tramadol have side effects including diaphoresis (excessive sweating) and xerostomia (dry mouth). Obviously, diaphoresis is going to cause you to become dehydrated more quickly if you don’t drink enough water to compensate. However, xerostomia can make you feel dehydrated when you really aren’t, which can lead to too much water consumption that causes an imbalance in which the kidneys can’t rid the body of the excess water fast enough.
Although very rare, too much water consumption can cause hyponatremia (low sodium) which in turn can cause a variety of neurological problems termed water intoxication, a condition which can be fatal.
While various beverages can be helpful in reaching your hydration goals, some beverages can affect your hydration adversely including:
- Energy Drinks
- Juice (specifically fruit)
Coffee, tea and energy drinks are typically consumed for the caffeine, which is actually a diuretic as well as a stimulant. This is why you have to run to the bathroom more frequently when you drink them. This is also what causes dehydration.
Juice, especially those that you buy at the grocery store, contain a lot of sugar, and the kidneys flush excess sugar (that isn’t stored as fat) from the body through urine, which is why diabetics tend to be urinate frequently and feel thirsty constantly.
Most people know that alcohol causes dehydration because that is what causes the hangover the next morning. The brain becomes dehydrated and you end up with a pounding headache that is directly proportional to how much you drank the night before. The best way to beat a hang over? You guessed it. Drink lots of water.
So, How Much Water Should You Drink?
It’s actually a difficult question to answer. How much liquid (ie: tea, coffee etc.) do you drink throughout the day? Do you put anything in them (ie: sugar, cream)? How many veggies do you eat? How much do you exercise? How intensely?
There is no one right answer. Personally, I have tried to increase my water consumption to about 67 – 84 oz a day (that’s four to five 16.9 oz water bottles). But one of my coworkers drinks a gallon (128 oz) of water a day!
Honestly, I don’t think I could drink that much. I have a hard enough time getting in 67 oz on days I don’t workout!
The truth is, eight 8 oz glasses of water (which is actually 64 oz) a day is actually a good rule of thumb, considering our bodies are made up of 80 percent water. If you happen to drink an 8 oz cup of tea without anything in it, you can count that toward your goal. If you put sugar in it, you might want to drink some extra water.
The best way to gauge your hydration? Take a look in the toilet. If your urine is a dark yellow, you’re dehydrated. If it’s pale yellow, or clear you’re drinking enough water. But if you take a lot of supplements, it’s going to change the color of your urine and throw off this “gauge.”
So bottom line?