165. The Ultimate Guide to Hydration for Runners

My name is Patrick McGilvray, and I’m an experienced marathoner, ultra runner, Sports Nutritionist, Master Life Coach, and weight loss coach for runners. I’ve dedicated my life to helping runners just like you properly fuel your body and your mind. So you can get leaner, get stronger, run faster, and run longer than you ever thought possible. This is Running Lean.

Hey there and welcome to episode 165 of Running Lean. My name is Patrick McGilvray, the weight loss coach for runners and today the ultimate guide to hydration for runners. So when it comes to proper hydration, most runners are kind of all over the place. And I get it. It’s a little confusing.

How much are you supposed to drink? How often? Should you only drink water? What about electrolytes is Gatorade the best option, etc, etc. Spoiler alert Gatorade to stay away from that stuff. It’s just sugar water. Okay. So today I want to end the confusion for you. I want to give you a very clear understanding of what hydration actually means for runners and how to do it properly. That’s why I’m calling this one The Ultimate Guide to hydration for runners.

So today you’re going to learn exactly what hydration means. The role electrolytes play in hydration, they are very important, by the way, how to hydrate before, during and after exercise, how coffee affects hydration, and loads more. So sit back, maybe grab a pen and paper for this one, because you might want to take notes. I have a lot of numbers for you today. And enjoy the ultimate guide to hydration for runners.

First, let me ask you this, does any of this sound familiar? You don’t need carbs to run, oh, you can’t run without carbs. You can’t lose weight while you’re running. You have to run in order to lose weight. You need to eat six times a day to keep your metabolism going. Eating less often will speed up your metabolism. Have you heard these contrasting ideas?

If some of these sound familiar, if all this sounds familiar, and you’re confused by all this like conflicting, conflicting information out there, you’re definitely not everyone has their own viewpoint and opinion of what works best. But the truth is there is no best way to do this stuff. Okay, the only thing that matters, the only thing that really should matter to you is what works best for you. Figuring that out, though, it’s kind of the tough part, right.

So a key component of my coaching program is putting together a personalized plan that actually works for you, a plan that will get you to your weight loss goals into your running goals much faster than you could probably do on your own. So if you want some expert guidance to figure out what works for you, then I think you’d definitely be a good fit for coaching. Stop the confusion and start taking expertly Guided Action to learn more and apply for coaching. Just go to runningleancoaching.com/apply.

Okay, let’s talk hydration. I really wanted to get into this topic today. And I’ve been thinking about this for a while and doing some research on this topic because I think it’s very important and something that a lot of runners overlook, or they think they have an idea of what they should do, but they’re maybe kind of misguided a little bit. And so I want to make sure that we have a deep dive in a detailed discussion on hydration. And so that’s why I’m calling this the ultimate guide to hydration for runners.

So let’s get into this. First of all, what is hydration? So hydration is basically the process of causing something to absorb water. Think about a sponge, you know, you take a dry sponge, it’s all like shriveled up and flat and then you add some water to it and it absorbs that water. It’s able to hold that water. Okay, so that’s hydration, very simple right?

Every cell in our bodies is made up of mostly water. So 70% or more depending on the cell but 70% or more of your total cell mass is water your brain all the all the cells in your blood your skin organs, muscles, bones, teeth all contain water. So hydration means that we are providing enough water to ourselves for them to function properly.

Okay, so just understand that at the base level, like hydration, is you know required for every cell in our body is required to be hydrated properly okay? That’s why we need water. We don’t drink water. We will die. You can live by the rule of threes – so three minutes without air, three days without water, three weeks without food, so you could go a couple days without water. But then eventually you’re going to die. So just keep that in mind. Drink your water.

So how much should you drink, though? I mean, this is one of the big questions, right? And people say, oh, you should drink eight glasses of water a day. Well, what’s a glass? How many ounces is that? How big is your glass? Is it sixteen ounces? Is it eight ounces? What is that?

So one of the rules of thumb that we can use, is to just take half your body weight and drink that in ounces per day. So if you weigh 180 pounds, then you know, 90 ounces of water is what you want to get per day. If you weigh 150 pounds, then 75 ounces of water is where you want to be. Yeah, this is for the average adult, right? This is not necessarily for an endurance athlete.

So if you’re somebody who’s training a lot, you’re going to require more fluid intake, you’re going to require more hydration, and we’re going to talk all about that in just a second. But I just want you to understand, at a base level, whatever your body weight is, just have that and that should be around where you want to be at a minimum, from from a water standpoint, just drinking water each day, okay.

So something to keep in mind, when you wake up in the morning, you are going to be dehydrated. And there’s a good way to offset this, which is by first thing in the morning, is by drinking 16-30 ounces of water just to start things off. And it’s recommended that you put some salt or some electrolytes in that water. And I’ll talk more about electrolytes in a minute. So just understand that you will wake up somewhat dehydrated. And how you can determine how dehydrated you are as an individual is by doing a simple test.

So that would be to weigh yourself naked before you go to bed. And then after you get up in the morning and you’ve urinated, weigh yourself again, and just kind of see how much water weight you lost overnight. And that’s a good indicator of maybe how dehydrated you are in the morning.

So being dehydrated is not a good thing. That means our cells are not functioning properly, our brains are not functioning properly, our nervous system is not functioning properly. And if you’re just one to 2% dehydrated, meaning that if you’re just if you’ve lost 1-2% of your body weight, due to dehydration, it can have a significant impact on your athletic performance.

Now I know a lot of people love working out first thing in the morning in that fasted state, I know I do, I don’t eat before I work out, I drink some coffee and then I hydrate before I work out. But if you’re starting your workout, and you’re already, let’s say 1% dehydrated, you’ve lost a few pounds of body weight overnight due to dehydration, and you’re going to start your workout in that 1% dehydrated state.

Getting yourself back to normal is going to be very challenging, like it’s really hard to do that with that hydration deficit that you’re going to be starting your workout in. So let’s say you have a long run, and you got a three hour run, and you’re starting this run at a 1% dehydration. So you’ve you’ve lost 1% of your body weight, it’s only going to get worse, it’s not going to be, it’s not going to get better, it’s going to be very hard to make up for that deficit, right?

Drinking while you’re running, it’s going to be really hard to drink enough to really make up for that. So training dehydrated can have a really negative impact on your athletic performance. So just keep that in mind. It’s great if you like to work out in that fasted state, just make sure you hydrate prior to work out.

So how much are we supposed to drink? Well for running, you know, for exercising. So for short bouts of exercise less than 30 minutes, let’s say you really don’t need to do much, you know, because you’re not going to lose much in the way of fluid. Okay? Typically, though, anything over an hour, you’re probably going to want to consume some fluids.

And this does depend on the weather and you know, the humidity levels and how much you sweat and things like that. But the one thing that I really want to get into here is making sure that we understand that when we talk about hydration, we’re not just talking about water alone, that we’re talking about electrolytes, electrolyte is like an umbrella term.

Basically it means particles that carry either positive or negative electric charge. So in nutrition we’re talking about essential minerals that are found in your blood, sweat and urine. So, when these minerals dissolve in fluid, they form electrolytes positive or negative ions used in metabolic processes.

So the electrolytes that are found in your body are sodium, potassium, chloride, calcium, magnesium, phosphate, bicarbonate. All of these electrolytes are required for various bodily processes including proper nerve and muscle function, maintaining balance, you know, like a pH balance and keeping you hydrated, okay? And so, the main electrolytes that we’re going to be kind of talking about are going to be sodium chloride, potassium and magnesium, sodium and chloride, basically salt, okay, so sodium, potassium, magnesium is kind of how we lumped those three together, okay?

Electrolytes are extremely important, they are crucial to keeping your nervous system and your muscles functioning properly. They help keep your internal environment balanced, like your pH levels balanced, okay? Without electrolytes, you’re really not hydrating properly. Remember, hydration is your body, drawing water into cells. And a critical part of this function is especially sodium.

So salt helps to make sure the cells don’t burst from being too full or shrivel up due to dehydration. So too much water is a problem. And a lot of athletes think that I just need to drink more water, drink more water, drink more water, but they’re not getting enough electrolytes and they’re not getting enough salt to mix with that water. And this can lead to a serious condition called hyponatremia. Hypo means low, na meaning salt, and then tremia is like in the blood. So basically it just means you don’t have enough sodium in your blood.

And hyponatremia can cause dizziness, lightheadedness, nausea, cognitive issues like confusion, or irritability, vomiting, and then there’s some very severe symptoms too with loss of consciousness, seizures, coma, even death. So drinking too much water can literally kill you. So you got to be careful with that, like, we don’t want to be just drinking plain water, you know, you’re out running an ultra marathon, and it’s hot out and you’re sweating a lot.

The more water that you consume, the more you’re diluting your system of sodium. And you will eventually get into some level of hyponatremia. And you have to be really careful with that. So we want to make sure that we are using electrolytes to hydrate properly. And again, electrolytes are required for proper muscle function and hydration and nervous system function and all these things, right. So just understand that we don’t when I talk about hydration, we really need to make sure we’re thinking about hydrating with water and electrolytes.

So how much do you need? How much electrolytes are you supposed to be, you know, consuming? So this is a little bit different for everyone, I’m going to give you some kind of averages here. And you can play around with this a little bit. Okay, and this goes to this whole discussion today. Which is like you have to kind of figure out what works best for you.

I’m gonna give you some ballpark numbers here, but just remember that it’s good for you to to play around with this a little bit. None of this stuff is like set in stone. Okay, so the first thing you need to determine is like, you know how much you’re losing in your sweat because when you sweat, then you want to replace the electrolytes that you lose in your sweat. So that you kind of replace that same concentration of electrolytes that’s in your sweat with the fluid that you’re drinking. Okay.

So for example, in one liter, which is 33 ounces, like one liter of sweat, I know it sounds disgusting, right? But one liter of sweat contains somewhere between 502,000 milligrams of sodium, 1-500 milligrams of potassium, and 0-100 milligrams of magnesium. So the averages in sweat would be somewhere around 1000 milligrams or a gram of sodium, 300 milligrams of potassium and 50 milligrams of magnesium.

Now there’s a product that you can get out there that I love. There’s lots of products for hydration. This one I just happen to love it’s called element LMNT. You can find it on Amazon or whatever. I don’t make any money off of this stuff. I just love it. I think it works great, it contains 1000 milligrams of sodium, 200 milligrams of potassium and 60 milligrams of magnesium. So it’s kind of hits, those numbers are pretty close to those numbers, right.

So basically, for every liter of sweat that you produce, you want to have one packet of LMNT added to water. And so, you know, let’s say, if you sweat out a pound per hour, then every two hours of running, you’re gonna want to have an element. Okay, that’s pretty easy, right? Again, these are sort of ballpark numbers, you need to kind of figure out what works best for you. But this is a good place to start here. Okay.

And then, you know, post exercise, just, you know, we want to make sure that we are, you know, replacing our fluids, you know, post exercise the same way that we do during exercise. Okay, and I’m gonna talk about that in just a minute, like, how to hydrate specifically during exercise?

Well, let me just talk about that right now. So how about this? How do we hydrate during exercise, or specifically, how do we replace lost fluids during exercise, the first thing you need to do is determine how much fluid you lose during exercise. So a great field test, again, is to weigh yourself naked before you run, and maybe go for an hour long run, after the run, dry off where you are again, and then you’ll see how much you lost. So this will give you a rough idea of how much water you know, you lose how much sweat you lose per hour.

So for every pound of water lost, we want to replace that with one and a quarter pounds of fluid. So we want that to be 125% of what we lost through sweat, we want to replace it with fluid that means electrolytes, right? water and electrolytes. So for example, if you weigh 150 pounds before you run, and then you come home from that run, and you weigh 149 pounds, you lost one pound during that one hour run. Okay? Pretty easy to do, right?

Then you just take 1.25 times that and that means that you know, during your next run, you’re going to want to run, you’re going to want to consume 1.25 pounds of fluid for that run. You also have to factor in water consumed during the run. So let’s say you take the same 150 pound person, you weigh yourself before you run, you drink eight ounces during that, so about half, and then you come back and you notice that you’re down to 149, you actually lost really 1.5 pounds total because you replaced eight ounces of that.

So then you would say okay, so what is 1.25 times 1.5? And that brings us to about 20 ounces, right? So 20 ounces every hour is how much that particular individual loses. Okay, so let’s break this down just a little bit more. Take that 20 ounces per hour and divide by four, because we want to know about how much we should be drinking every 15 minutes. This makes it so much easier, right? Because you’re not going to chug 20 ounces every hour, so top of the hour better chug 20 ounces of water. That is not going to be a good strategy for running. Okay.

So that means that we want to break that 20 ounces down over every 15 minutes. So that’s like five ounces every 15 minutes, right? So pretty easy math once you once you do this. Okay, so let me let me repeat, you know, kind of replay this right here. So for every pound every 16 ounces of water last, replace it with 1.25 pounds of fluid or one 125% of the ounces of fluid lost. Okay, that’s it, that’s all you have to remember right there. And then just divide that by four so that you’re, you know, consuming, you know, a little bit every 15 minutes or so. Okay.

Now, there’s another formula that you can use, if you don’t want to do the sweat test where you weigh yourself before and after, you can just take your body weight and divide it by 30. And that’s how many ounces to drink every 15 minutes. This is kind of an easy way of doing this. So let’s say you weigh 150 pounds, divide that by 30. That’s five, five ounces every 15 minutes. That’s it. Simple, right?

I like this one because it kind of jives with you know what most people kind of find there. And it gives you just enough, it gives you probably a good place to start. All right, and then you need to kind of figure out what works best for you and then remember, these numbers will go up or down based on how hot it is outside, how humid it is, and how hard you’re training. So you have to experiment with this, like what works for you may not work for other people, what works for them may not work for you. Okay?

So now that we understand that, when you are done with exercise, you want to have that same formula that 125% of fluids are lost during exercise. So even though you’ve hydrated during, maybe you still come back and you’ve lost some weight because of a little bit of dehydration, even though you’ve been drinking, it’s fine. Not a big deal. Just replace those same fluids lost using the same concentration of water, electrolytes and that 125% rule, okay?

So another way to tell if you’re getting enough fluid and electrolytes, and I know this is a great one for ultra runners, because they’re always asking about their weight, they’re looking at their urine, you want to make sure your urine is not a dark color. You want to make sure you’re not losing too much weight. And then how thirsty are you feeling? So we call this what w u t? WUT?

So is your weight down? How much have you lost in the way of fluids? And then we look at urine; what color is it? Is it clear? That’s a good sign. Is it dark colored? Like stout beer? That’s a bad sign. And like how thirsty are you or do you feel very thirsty or not really? Okay. So if any one of these weight, urine or thirst if you can answer yes to any of these; urine is kind of dark and you’re feeling thirsty? Yes to any one of these, you might be a little dehydrated, okay?

If two or three or yes or three or yes, that you’re definitely dehydrated, okay, so then you need to probably up your hydration game a little bit. So maybe the kidney you didn’t plan for the conditions or something like that. Okay. Now, another way of determining what your salt needs are, is, you know, if you’re craving salt, you may need to eat more salt. If the food you’re eating just doesn’t taste salty at all, and you keep adding more salt to your food and it starts to taste fine, then you probably don’t have enough salt in the system. All right.

So if you’re craving salt, eat more salt, if what you’re eating tastes super salty, and you go for one of these electrolyte drinks. And you’re like, Oh, this is so salty then maybe you’re salted enough. Like you don’t really need to add more sodium into your system. So go by sort of that moat, we call it the salt appetite. Like how is your salt appetite? Do you crave salt, you want more salt, and maybe you need a little bit more. But if you’re not, then you might be okay.

And keep in mind the RDA, the recommended daily allowance for sodium intake is like 2300 milligrams a day. So that’s for people who are eating a typical American diet, who are eating maybe a lot of carbohydrates, a lot of processed foods. When you eat a clean diet, when you’re maybe doing sort of a lower carbohydrate intake, you’re doing lots of endurance activities, where you’re losing a lot of sodium through sweat, you can probably up your salt game, you can probably up your salt intake, from that 2300 milligrams a day to 3000 milligrams a day, maybe even up to 5000 milligrams a day. Depends on you as an individual.

Now, if you have pre hypotension or hypertension, you have to be careful with salt. Talk to your doctor about what numbers are right for you. Chances are that you’re gonna have to keep sodium probably a lot lower than some of these numbers that I mentioned here. Okay, so definitely talk to your doctor and see what you know they recommend for you. Okay, yeah, and another thing about processed foods is that a lot of people who kind of switch and start eating a lower carb diet, they’re not getting enough salt all of a sudden.

So they may have been close to that 20 303,000 milligrams of salt per day. And then they start eating really clean foods, they start eating a lot less processed foods, and their sodium intake goes way down and they don’t feel good. You know, they still maybe have a little lightheadedness, headaches, a little bit of brain fog or something like that. So if you eat pretty clean, you might want to just try adding a little bit more salt to your diet to see if you feel better, you’ll probably feel better perform better. You’ll have better brain function, you’ll probably sleep better too. Okay.

And then electrolytes, you know, this question has come up before like, should I use electrolytes only when I’m running or should I use them other times? And the answer is yes. Yes, you should use electrolytes every day. It’s vital for sports performance Yes, but also vital for proper brain function. It’s vital for maintaining pH levels, it’s vital for nerve and muscle functions and all the stuff that I mentioned earlier, okay.

So, you know, just keep in mind that we want to take electrolytes on a daily basis, and make sure that we are hydrating before, during and after exercise. And then really quickly, yeah, how to hydrate before exercise. So a good place to start with this is maybe around 500 milligrams of sodium, right, so what you want to do is 30 to 60 minutes before exercise, go ahead and preload with some salt or electrolytes, and water, maybe 16 ounces of water, so and then over the course of about 15 to 20 minutes, sip that water, don’t just chug it all down at once.

Because what this will do is it’ll help to increase blood volume, it’ll actually give your body more blood to deliver oxygen to working muscles. So this is a very easy and very simple performance enhancing hack, right, just by pre-hydrating before you exercise. So that way, you’re not starting off your exercise in that dehydrated state. So one of the first things I do every morning is while I’m making my coffee in the morning, I add salt to 16 ounces of water. And I drink it. And that’s how I start every day that way. I know that no matter what my exercise looks like that day, whether I’m lifting weights, or running that I know I’m like starting out with some level of hydration. Okay.

Oh, what about coffee? People ask about coffee and they think that it’s, you know, maybe dehydrating. You know, people talk about, you know, caffeine being a diuretic, and it’ll actually dehydrate you. And that is true coffee, or caffeine on its own is a diuretic and will dehydrate you it will cause dehydration.

So if you’re taking caffeine pills, it will probably cause some dehydration. But if you’re drinking brewed coffee, which is mostly water, then the effect of that dehydration is beaches basically neutralized so you don’t really need to worry about coffee being D dehydrating or a diuretic because it really won’t do that to you as long as it’s got all that water. So if you are somebody that takes caffeine pills, just make sure you drink plenty of water with them to kind of offset that and you’ll be fine there.

Okay, and just coffee is a proven performance enhancing compound so use it but not too much. One to two cups of coffee, pre workout seems to really enhance exercise performance. Three plus cups of coffee can start to cause some performance degradation. So, you have to be careful not to overdo it with the coffee or the caffeine. So this is good news. Right? If you like drinking coffee, then you’re good to go there. It’s not dehydrated at all.

Okay, I hope you got something out of this episode. I hope you understand hydration, how to hydrate before, during and after exercise. What electrolytes are, how much to use, when to use them. If you have any questions, reach out, I’m always here for you. But that’s all I got for you today. Love you all, keep on Running Lean, and I will talk to you soon.

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