Water is Important! Here’s How to Best Hydrate When Running
Updated: Feb 22, 2021
Water is important. We all know it. Our bodies are made of 60% water. Our brains are made of 75% water. Our bodies need water to thrive and survive. Yep, you’ve heard it all before.
You know you need to drink water when you’re out on a hot or long run. If you don’t, your body tells you. You get that parched feeling in your mouth. Your muscles start to cramp. Or you bonk halfway through a run you’ve done dozens of times.
Hydrating while running is important. Let’s take a closer look at why it’s important, the best hydration strategies for running, and signs that you aren’t hydrating enough on your run.
Why Is It Important to Stay Hydrated While Running?
You need to be hydrated to have lubricated joints, to regulate your body temperature, and to have healthy blood circulation.
Your muscles are 75% water! If they aren’t properly hydrated, of course, they aren’t going to function optimally. A lot of people overthink feeding their muscles. When to eat carbs vs. protein. How much protein to eat. But have you ever thought about how much water you give them?
Your blood is 90% water. Staying properly hydrated helps your body to regulate blood pressure, especially when you exercise. If your body has to work extra hard to pump blood throughout your body, it’s going to have less energy to help propel you forward on your run.
You need healthy blood for healthy muscles. Your blood is what brings oxygen and nutrients to your muscles, and what removes by-products and waste from them. You’ll want good circulation and hydrated blood if you want healthy, hydrated muscles .
Your brain is 75% water. You need a hydrated brain in order to think clearly, make decisions, and regulate emotions. Translated to running, you need a hydrated brain to maintain a positive mindset so you don’t quit, to even remember the goal of the run you’re on, and to be able to make on-the-go judgment calls out on trail .
Overall, here are just a few aspects of running that can be impacted by your hydration (or lack thereof):
Reaction Time 
Two Main Strategies for Hydrating when Running
Hydration Strategy #1: Drink When You’re Thirsty
The main argument for the “Drink When You’re Thirsty” strategy is that there are a lot of factors that go into how much water you lose when you’re running…
What’s the temperature outside?
How hard are you working?
How long is your run?
Are you well-rested?
With all these factors affecting your hydration, how do you know how much water to be drinking?
This strategy argues against the preset amounts and intervals of drinking water. Not everyone is losing the same amount of water at the same rate. And not everyone starts their runs at optimal hydration levels.
With this strategy, you listen to your body. Being thirsty is your body’s way of telling you that it needs more water! So then you drink.
Some issues with this strategy:
Some people argue that your body tells you it’s thirsty when it’s already dehydrated. On a run, this could mean you’re already experiencing some impaired decision-making, clarity, and performance.
It requires the runner to be able to tune into their body. You’ll want to drink at the first sign of thirst. When it’s saying politely to you, “Excuse me, kind human, could you please give me a little bit of water? I’m starting to sweat a bit. Why thank you very much, kind soul.”
If you don’t realize you’re thirsty until your body is screaming, “Give me water… NOW!!” then you’re already dehydrated.
If your body is screaming at you, you’re also more likely to chug large amounts of water due to your level of thirst. On a run, this can lead to stomach cramps that could impact your performance.
Hydration Strategy #2: Drink Before You’re Thirsty
This strategy requires you to stay ahead of your thirst. You drink set amounts of water at set intervals before, during, and after your run.
The main argument for the “Drink Before You’re Thirsty” strategy is that once you feel thirsty, you’re already dehydrated.
So you may follow a set hydration guide like this one:
Some issues with this strategy:
Like we already talked about, there are a lot of factors that could affect how hydrated (or dehydrated) you are throughout your day and throughout your run…
What’s the temperature outside?
How hydrating are the foods you eat throughout the day?
How much alcohol are you drinking at night?
What’s the intensity level of your run?
So sticking to a set schedule doesn’t take individual bodies and life situations into account.
A 5’ female that is out for an easy recovery run probably doesn’t need as much water as a 6’ male that is out doing sprint work. It’s just not that simple.
So What’s a Runner To Do? Hydration #1 or Hydration #2?
Go with Hydration Strategy #3… A Hybrid of the Two
Like most things in life, the ideal solution isn’t with either extreme, but likely somewhere in the middle. Drinking before you’re thirsty all while listening to your body.
Here’s an example of how this strategy might look…
All the while, keeping note of how you’re feeling. If you’re thirsty after 10 minutes, have another sip. If you feel like your belly is sloshing around with too much water, drink less.
Still try to drink before you’re thirsty, but there’s no need to stick to strict regulations of water intake.
How to Carry Water While Running
Okay, you’re convinced. You need to drink water before, during, and after your run. You need to listen to your body. But how do you carry water on your run?
You don’t exactly want to be running down the trail with a water bottle sling bouncing against your bum with every step. You know that. But the options are almost endless with types and brands of running hydration gear. It can be a bit overwhelming, but there are a few key areas to zero in on to find the right method for you.
In the end, it comes down to personal preference, and I’ll talk about my personal opinions on the pros and cons of each. But it’s important to choose the option that works best for you. The option that you’ll actually use and not be annoyed with throughout your entire run.
A running vest tends to provide the most versatility for your water-carrying needs. A lot of vests offer the option to either carry water in a bladder on your back or have collapsible water bottles in pockets in the front. Some also offer the option of both, but you may have to purchase the bladder or the bottles separately.
Running Vest Bladder
A vest with a bladder could be the best choice for you if you’re out on a long run. Especially one that doesn’t have any water sources available along your route.
It’s the option that allows you to carry the most amount of water. Most bladders I see allow you to carry 1.5-2L of water. If your vest fits properly, it should just feel like a small, compact backpack as you’re running.
The bladder has a hose that runs up to your mouth, making it a convenient water source on the go. The hose then typically attaches to the front of your vest, so you don’t need to worry about it smacking you in the face with every step 😂
Obviously, with greater water carrying capacity comes added weight. Even with a perfectly-fitted vest, this added weight can create a bit of a bounce effect when the bladder is full. An easy workaround is to not fill the bladder all the way if you won’t be needing a full 2L on your run.
Another downside is that you’ll need to take your vest off every time you want to refill the bladder. In a race, this can become a bit of a hassle. But you can master the art of getting your vest and bladder ready coming into an aid station to refill like a pro.
A few tips on how to refill your bladder during a race:
Coming into the aid station, unclip the hose and start to loosen your vest. Wait to unhook the clasps. When you’re in the aid station, unhook the clasps and take your vest off.
Don’t forget that first step of unclipping your hose! I can’t remember how times I’ve forgotten to detach the hose only to have it stop me from getting my vest off - whoops! Ha!
The vests I’ve used (UltrAspire and Salomon) have an easy-access section for the bladder itself. So yes, you have to take your vest off but a lot of your other items in your vest remained untouched.
If you’re buying a vest and bladder, be sure to look for an easy access bladder location. Also, look for a bladder that can open easily and has a wide opening.
Another tip when refilling at an aid station... If you can get someone to work the water spigot for you, use one hand to keep the bladder open and the other to hold the weight of your vest.
If no one’s there to help, no worries! I recommend grabbing the opening of the bladder and vest in one hand and use your other hand to work the spigot. You may also need to lift a knee to the bottom of your vest to help steady everything.
Running Vest Front Water Bottles
A lot of running vests also allow for collapsible water bottles that are stored in front pouches. This is my current preferred water-carrying method.
The collapsible water bottles allow you to suck on the nozzle, much like a hose but with a bite valve. You don’t need to remove them from the pouch to drink from them.
You can also remove the bottles and refill them without completely removing your vest.
That being said, I do often find myself loosening my vest to remove the water bottles. I’ll loosen the vest coming into an aid station. I start taking the bottles out and getting them ready as I approach the water station. Doing this cuts back on both time and hassle at an aid station when you want to stay focused on your race.
If you’re having difficulty taking your front water bottles in and out of your vest, I made a video that demonstrates how I do this. Check it out here on Instagram.
As far as comfort goes, the weight of the water bottles is split between the two sides. So the bounce effect is lessened.
I also like that I have a better idea of how much water I have left on a run. With the bladder in the back, it’s more difficult to judge when exactly I’ll run out.
After years of running with a bladder on my back, it did take some getting used to the added weight on the front. That being said, I did get used to it and it’s no longer something I have to think about.
Each water bottle typically holds 500mL, making your water capacity just 1L. Depending on your run, you may need to carry more than that. A lot of races also require you to have 2L of water carrying capacity.
As a workaround, I will still use my front water bottles, and bring my bladder along as well. Most races only require you to have 2L of carrying capacity. That just means the ability to carry up to 2L of water. Obviously, check your race for specific requirements.
If you know aid stations will be plentiful, you don’t actually need to start with a full 2L in your vest.
Sometimes you do need to start with 2L of water, or you know there’s a long stretch between aid stations coming up. In that case, I’ll partially fill my bladder and completely fill my front water bottles.
With running belts, there are a lot of options out there for different fits and carrying capacities. Do you want two water bottles in the front? One larger bottle in the back? Do you want all 3? Or multiple all around the belt? What kind of pockets do you want for keys, phone, food, etc?
They’re great for runs when you don’t want to carry a lot of gear with you. For example, you may want to carry some water on a shorter run in the summer heat, but you don’t necessarily want an entire vest or gear. A running belt could be a handy alternative.
For longer runs, a running belt may not have enough water carrying capacity. There’s less carrying capacity in general, actually. But we’re just talking about water here.
They also tend to bounce more than a vest, which becomes more apparent when you’re on the varied terrain of trails.
The final downside to running belts is that you need to remove the water bottles in order to drink from them. When you’re out on trail, this could be an added hassle and distraction when you’re trying to avoid roots and rocks.
Personally speaking, I found a belt nice for longer road races. But I quickly found I need more water carrying capacity on trail. I also want the ability to carry more food and gear as the runs get longer.
Handheld Water Bottles
I’m not necessarily talking about just carrying a Fiji water bottle on your run. They do make running water bottles that are meant to fit comfortably in your hand as you’re running. They also often provide a small pocket for keys, ID, etc.
One benefit to handheld water bottles over a running belt is that you don’t need to remove the water bottle to drink from it.
It could also be a good option for those shorter runs where you don’t want a lot of gear. And for capacity, there’s always the option to carry one in each hand.
I’ve actually seen some pro trail runners using handheld water bottles. It’s just another option to consider if you only need a handheld water bottle or two.
There is very limited storage space with handheld water bottles. But as I said, there’s typically enough storage for the basics like keys and ID.
Some people find it a bit awkward carrying something heavy in their hands while running. Other people say they get used to it with time. Either way, it can definitely be an added upper body workout, ha!
Careful Route Planning
By “Careful Route Planning”, I’m referring to not actually carrying any water at all. But instead, planning your route to go by water fountains, other water sources, or even stopping by home.
The most obvious pro with this method is that you don’t have to carry any gear! You don’t have to worry about guessing how much water you’ll want to drink, and there’s no added weight.
You may also find yourself not needing as much water on your regular runs. So again, be mindful and smart on this one.
You run the risk of a drinking fountain being out of order. If something doesn’t go to plan, you don’t really have a backup water supply.
You also don’t have on-demand access to water for when you’re feeling thirsty. This could get dangerous on a hot day if you need water, but your next drinking fountain is still a couple of miles away.
The planning for this method could get a bit tedious, not to mention not be an option depending on the trail network. Especially when you’re already trying to plan for distance and maybe elevation. But, it’s been done before and could be an option for you in a pinch.
Symptoms of Dehydration After Running
Your run is completed. You think you kept up on your hydration needs. But how do you know?
Well, if you’re really curious, there’s a test you can do on yourself. It does include getting just a little bit up close and personal with your urine. But for curious minds, it could be a fun experiment and source of data for your ongoing hydration strategy.
Step 1: Run - Complete your run as usual, including your regular post-run hydration routine.
Step 2: Drink Water - After an hour drink 3 cups of water, which is equivalent to 24 oz or approximately 700ml.
Step 3: Wait - Wait for an hour. Go about your day per usual, just don’t go to the bathroom!
Step 4: Eliminate - Urinate into a cup. You’ll want to capture all of your urine, so choose a large enough vessel!
Step 5: Assess - If you eliminated less than 1 cup (8oz or 235ml), then you were dehydrated! Time to rethink your hydration strategy...
If you don’t feel like filling a cup with urine after every run, instead, learn to watch out for these symptoms of dehydration:
Sleepiness and Fatigue
A Racing Heart or Dizziness
For more information about these symptoms of dehydration, check out this article: 9 Dehydration Symptoms You Need to Know About
I’d love to know, what are your strategies for staying hydrated while you’re running? Drop them in the comments below. 👇
Want to know more of the must-haves when going on a trail run? Check out the post: Trail Running? 11 Things You Don’t Want to Forget, or sign up for my newsletter and receive a free printable Long Run Gear Checklist.
Jillian Beckham is wife to Brent, and also a fan of the front vest water bottles. She’s also a health and wellness copywriter. If you need help writing blogs (like these), newsletters, or website copy for your own business, check out her website, www.beckhamcopywriting.com. Or sign up for a free 30-minute consultation.