Hydrating sounds simple enough...

Drink water, often.

But once you take a closer look, staying properly hydrated for workouts, general health, longevity, and feeling your best isn't as straightforward.

... How much should I drink when running?

... Do I need electrolytes?

... Does coffee and beer count towards my fluid intake? 

With hydration playing a crucial role in everything from regulating body temperature to lubricating joints and delivering nutrients and energy to cells, a little attention can go a long way.

To help us understand hydration best practices, I asked Dr. Estello Nap Hill, MD, an Internal Medicine Resident Doctor and plant-based ultra-marathon athlete to weigh in.

Check out his advice, here:

Dr. Estello Nap Hill, MD, Hydration FAQ Notes

00:25 - How much water should I drink every day?

It depends. How much we drink should be individualized and it depends on things like your activity level, how hydrated you are the day before, and the humidity and temperature outside.

A good place to start is trying to drink half your body's weight in ounces.

So for example, I'm 200 pounds, and I try to drink about 100 ounces of water a day which turns out to be about three liters of water.

But being hydrated is not just what you drink. It's also what you eat.

Did you know that plant-based foods have 80 to 90% water content while other foods such as processed or fried foods have a lot of the water cooked out of them? So when you're trying to look at how much water you're getting in a day, it's what you drink but also what you eat.

01:55 - What happens if I don't drink enough water?

Water is the second most important thing that your body needs, second only to oxygen.

What happens when you don't drink enough water? You get dehydrated.

Some of the signs of dehydration are decreased urine output, increased thirst, fatigue, irritability, and when you're really dehydrated, it can lead to things such as a really low blood pressure and it might even land you in the hospital or the ICU. Clinical dehydration aside, there's also a lot of evidence to support that even a little bit of dehydration can affect athletic performance.

Losing 1 to 2% of body weight in water has been shown to have a 10% reduction in exercise capacity. In addition to that, it also has been shown to increase the perceptual strain of exercise, which means that even if you're able to do the same amount, it's gonna feel a whole lot harder

03:15 - How much should we drink when we're working out?

Did you know you can lose up to one to five pounds of sweat per hour while working out?

Sweat is not just water. It's also got electrolytes like sodium, chloride, potassium, magnesium, and calcium. So it's really important that when we're rehydrating during, after and before exercise, we're using a solution that's not just water but that's also got the electrolytes that we need.

How much water you should drink during a workout depends on your body weight, your exercise intensity, how long you're exercising, and the heat and humidity that's in the area around you.

There are a few different formulas you can use to calculate how much exactly to drink when working out.

And one of the ones that I like to use is to take your body weight in pounds and divide it by 30. And then, you're gonna drink that amount in ounces every 15 minutes.

The best way to estimate how much you've sweated out during a workout is simply to weigh yourself before and after. You should try and drink the amount that you lost and then a little bit extra to make up for stuff that you're gonna pee out.

So for example, if I lost a kilogram of weight while working out, I would try to drink a liter to a liter and a half of an electrolytes solution after my workout to replenish those losses.

It's important to be extra hydrated after your workout so that you can be fueled up to go into your next one.

04: 48 - Does coffee, soda, or beer count towards hydration?

You may have noticed that when you drink coffee or beer, you have to pee a lot. That's because it's a diuretic.

A diuretic is something that makes us go pee more often and more frequently. The way that caffeine and alcohol make us pee more is it inhibits a hormone called antidiuretic hormone. And that causes us to pee out more water rather than reabsorbing and keeping it in our bodies.

That said, the amount that you pee out isn't as much as the amount that you get from drinking the coffee. You're not gonna pee out so much water that you're gonna become dehydrated.

But because you're peeing more and you're getting only a little bit of the fluid you're drinking, it's not the best choice for a pre-hydration.