Have you heard that you’re supposed to drink eight–eight ounce glasses of water a day? What about the one where you take your weight, divide it in half, and that’s how many ounces of H2O you’re supposed to get? Or what about the idea that you don’t need to drink water because you get enough from your food?
The truth is: optimal water consumption varies for everybody.
Hydration recommendations can be a confusing land to navigate. That’s because it’s not as simple as one baseline suggestion for everyone. The amount of water you need to drink in a day depends on your weight, sex, activity level, diet, and even where you live.
The Institute of Medicine has determined that for an average-sized healthy man living in a temperate climate with a moderate activity expenditure has an Adequate Intake (AI) level of fluid of about 3 liters per day (it’s 2.2 liters for women).
So, what does that mean in English?
Well, if you’re a guy, who’s a healthy weight, does an average amount of exercise, and lives in a mild to moderate climate, you need a minimum of three liters of total fluid in a day. And fluid means more than just straight up tap water. Juices, milk, and even coffee can count to your total. But really, plain water is your best choice because it’s calorie free, doesn’t spike your blood sugar and doesn’t have other chemicals that affect your body (think: caffeine).
So what if you aren’t an average-sized person living in an average climate with average energy expenditure? Well, chances are, you need even more water.
Here are a few factors that might up your need:
- Exercise. Love a good sweat session? If so, you need to be drinking more water to replace that sweat. Keep in mind that you not only lose water, but also electrolytes during heavy exercise. Sports replacement drinks (I love the dissolvable tablets without added sugar) are a great way to keep your electrolyte balance intact.
- Climate and altitude. Where you live can greatly impact how much water you need. If you live in a particularly hot and humid part of the world, you’ll need to stay hydrated more than someone that lives in a cooler climate. Live up in the mountains? High altitude can trigger symptoms of dehydration. Folks who live in high altitude areas need to drink more than the standard AI.
- Health conditions. If you’re feeling under the weather, you’ll need to be downing more water than usual to keep your body in good condition to get healthy. It’s especially important to drink more than the AI if you have a fever or diarrhea.
- Pregnancy and breastfeeding. Not only are you eating for two, but you’re also hydrating for two. It’s important for pregnant and breastfeeding women to drink more than the AI level of fluid.
Great, but really, how much water should I drink?
If all of this sounds too complicated, you’re in luck, because unless you have a medical condition that otherwise prevents it, your body gives you all the tools you need to determine your proper hydration levels. If you’re drinking enough during the day to rarely feel thirsty, you are in good shape. Also, check in the bathroom, if your urine is colorless or very pale yellow, you’re on the right path. Sometimes, just keeping an eye on your own body and how you feel is better than any recommendation you could read from even the most reliable source.