What To Drink Before A Run: Stay Hydrated The Right Way


Have you ever felt so fatigued just an hour into a long run? One thing that might be causing this – hydration. Or, more specifically, lack of hydration.

What to drink before a run sounds simple enough. But get it wrong, and it can ruin a run.

Stay hydrated the right way, though, and you can look forward to smooth sailing from start to finish.

Here’s our advice.

Why Is Pre-Run Hydration Important?

Hydrating matters during your run. But it’s what you start doing an hour or two before that makes the greatest difference. Because that dictates your state of hydration when you take that first step.

If you start your run already dehydrated, you’re setting yourself up for a difficult run. You might not feel it, but the effects of dehydration will already be setting in.

But hydrate yourself upfront, and you’ll not only have energy in the tank from the beginning, but you’ll be able to maintain it throughout your run.

What Happens if You Don’t Drink Enough Water Before a Run?

Even if you don’t feel it, inadequate pre-run hydration can—and most likely will—affect your performance. Here are some of the ways it can negatively impact you:

Reduced Endurance

Dehydration can lead to you fatiguing far earlier than normal. Without adequate water, oxygen and nutrients get transported to the muscles more slowly, which means they work inefficiently.

Slower Pace

The more fatigued you become, the slower you’ll get. This is because both the cardiovascular system and the muscles rely on delivering oxygen and nutrients to help them perform. When you’re dehydrated, that doesn’t happen.

Decreased Mental Focus

Dehydration doesn’t just affect you physically. When the fluid volume in your brain drops, your critical thinking skills, mental focus, and motivation all go out the window. This can make it even more difficult to push through those tough physical moments.

Increased Perceived Effort

The more fatigued you become due to dehydration, the more effort you’ll have to put in to stay at the same level of performance. This will make you feel like you’re working so much harder and yet going slower.

Muscle Cramps

Aside from general fatigue, your muscles can cramp if they don’t get nutrients.

This can significantly hamper you during a race and even cause you to DNF.

Higher Heart Rate

The more dehydrated you are, the more your blood volume will decrease. This means your heart has to work harder to get oxygen to your muscles, so your heart rate will increase, placing extra stress on your cardiovascular system.

Difficulty Regulating Body Temperature

Dehydration impairs your body’s self-regulatory abilities, which means you’re more likely to suffer severe effects of the heat. Not only can this knock you down and ruin your run completely, but it can actually be life-threatening.

Increased Risk of Injury

When your muscles and cardiovascular system are fatigued, your running form is soon to follow. As well as poor form, you’ll likely suffer from reduced coordination, leading to a higher chance of injury.

Longer Recovery Time

Even if you do finish your run and do fairly well, you’ll need a longer time to recover if you weren’t adequately hydrated. This could hamper your future running plans and leave you drained and exhausted.

When and How Much Should You Drink Before a Run?

Avoid downing a lot of water just before your run starts, or you’ll quickly require a bathroom break! Ideally, you want to drink around 16 ounces of water or a sports drink between 2 hours and 1 hour before your start to run.

This will give your body time to absorb and hydrate you. From there, you’ll be well-hydrated for a short run or able to maintain your hydration by drinking during a longer run.

What to Drink Before a Run

Your choice of drink matters. While many runners swear by sticking to water, there are other options.

Avoid too much caffeine, carbonated drinks, and sugary drinks. These are better options:


The best of the best. It’s super hydrating, and your body needs it.

The one downside is that water doesn’t have electrolytes, which means you should supplement with something else while running. But for pre-run hydration, it’s ideal just as is.

Coconut Water

Coconut water is refreshing and contains natural sugars that can give you a bit of a carbohydrate boost. Plus, it’s tasty!

Flavored Water

Choosing water with natural flavoring is okay. Avoid carbonated flavored waters. If you want to, you can flavor your own water by adding a few slices of fruit.

Sports Drinks

Sports drinks come in many varieties, so we recommend doing your research and choosing a healthy one. Avoid sugar-laden energy drinks, as they’re designed to give you a brief surge of energy but will most likely cause you to crash.

Find a healthy, natural sports drink containing carbs and electrolytes. While these are most useful mid-run, you can hydrate with it before your run so you start off with a bit more energy.

A Cup of Coffee

The caffeine in coffee can drum up some energy, but be warned—it can also accelerate fluid loss. If you opt for a coffee before a run, we suggest black coffee—creamers and milk can lead to digestive issues if followed by exercise.

Freshly Squeezed Fruit Juice

Freshly-squeezed fruit juice is an excellent choice. It’s packed with vitamins, minerals, and healthy, natural sugars without a lot of fiber, so it’s unlikely to cause stomach issues.

Tailoring Hydration to Your Running Routine

A hydration strategy should be personal. You’ll need to spend some time figuring these factors out before you create yours, and it’s also worth noting that you can’t use the same hydration strategy for every run.

Short vs. Long Runs

You’ll need to carry more water with you on longer runs because the longer you’re exercising, the more fluid you’ll lose. For runs under an hour, you can get away with just a bottle of water, but for runs longer than that, you’ll most likely need electrolytes too.

Make sure you take enough water with you based on the length of your run. If you know there’s a water fountain or something along your route and you’re happy to stop for a minute to fill up a bottle, then factor that in as well.

Intensity of Your Workout

The more intense your run—or any other workout—the more fluid you’ll lose. You need to use your discretion to work out whether you might need extra hydration for short runs if they will be intense.

Easy workouts won’t need quite as much water, but don’t fall into the trap of neglecting hydration just because your run isn’t intense! Up your water intake if you’re doing intense runs, like intervals.

Consider Weather Conditions

The hotter it is, the more you’re likely to sweat. This means you’ll need to make sure you’re replenishing water and electrolytes if you want to stay hydrated. In the heat, you might want to take extra water and a few extra electrolyte tablets, especially for longer runs.

But don’t get complacent in cool or overcast weather. It’s still easy to become dehydrated even if the sun’s not out.

Your Sweat Rate

Everybody’s sweat rate is different, so if you want to tailor your hydration more specifically to you, it’s a good idea to know yours.

Simply weigh yourself before your run and jot down that figure. Then do the same after your run, as soon as you can. Between those two numbers, figure out how much you lost in pounds, and convert it to ounces (x 16).

Once you have that number, add the amount of fluid in ounces that you drank during your run. To get your final answer, divide that number by the hours you ran.

The easiest way is to do a 1-hour run, which will make the last calculation easier to reach. We recommend doing this test 3 times—once in cold weather, once in mild weather, and once in hot weather, to get 3 different sweat rates.

We also recommend repeating it every few months, because it will change as you get fitter and healthier.

How to Recognize Dehydration

Dehydration sneaks up on you if you aren’t careful. It doesn’t matter if it’s hot or cool, it’s a risk for every runner. Knowing the signs can help you identify it early and counteract it before it becomes severe enough to stop your run.

The first signs you should be keeping an eye out for are feeling thirsty, a dry mouth, and feeling less energetic than you should be. You should drink the moment you feel thirsty, and if you do catch yourself in these moments, make an effort to pay more attention to drinking.

If you don’t rehydrate at this point, the symptoms can progress to worse ones like:

  • A dull or buzzing headache
  • Nausea
  • Dizziness
  • Muscle cramping
  • Unusual fatigue

These are bad signs and indicate that you need to stop and hydrate. If you don’t, you’re heading into territory that could have life-threatening effects. Remember to drink slowly when you rehydrate—gulping water can make you feel nauseous.

Hydration Mistakes to Avoid

Create a hydration strategy, and be aware of these mistakes. Avoid these along the way, and your hydration strategy should work well.

Waiting Until the Last Minute

The body needs some time to absorb water after you drink it, so don’t wait until right before your run to start drinking.

You may need to experiment to find the ideal balance between drinking too soon and needing to run to the bathroom and drinking too late and starting the run dehydrated.

Not Drinking Enough Fluids Throughout the Day

Hydration isn’t just important before and during a run. Make an effort to stay well-hydrated from morning until evening.

Drinking to Many Caffeinated or Sugary Beverages

Too much caffeine before your run can have a diuretic effect, increasing fluid loss during your run and throwing your strategy off. Alternatively, some people may have a worse reaction to caffeine—an upset stomach during the run.

Also, avoid sugary drinks before your run or too many during your run, as they can cause the typical “sugar crash” and leave you with less energy during your run.

Neglecting Electrolyte Intake

You can drink all the water you want, but if you aren’t replenishing electrolytes, you’re setting yourself up for a nasty crash. Make sure you factor electrolyte supplements into your hydration strategy, especially for runs longer than an hour.

Ignoring Weather Conditions

Don’t disregard the weather when it comes to hydration. If it’s hot and humid, you’ll need to adjust your strategy to ensure you remain optimally hydrated.

Not Considering Individual Hydration Needs

You can’t just grab a hydration plan off the internet and immediately get great results. Every runner is different, so it’s crucial to tailor your hydration strategy to your needs, based on your size, fitness level, and even your sweat rate.

Disregarding Urine Color

It might not be fun to check the color of your urine, but it can be an excellent indicator of your hydration level. We advise checking it every time you go to ensure you maintain good hydration throughout the day.

Relying on Sports Drinks Unnecessarily

Sports drinks containing electrolytes are handy additions to your fueling strategy. But if you’re opting for a sports drink over water during shorter workouts when you don’t need the extra calories or sugar, then you should reconsider.

Using sports drinks when unnecessary can lead to a high sugar intake, excess calories, and less hydration than you think. If you drink them daily, you might also be at risk of unbalancing your own electrolytes, which can have severe consequences.

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Ben is an avid road and trail runner, and has completed multiple marathons and ultras. A former running store owner, he now shares his knowledge and experience writing these articles.

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