Hydration for runners: are you drinking enough?

We all know we need to keep ourselves hydrated

hydration for runners

Sensible nutrition is important for athletic performance. Yeah. You all know that! But are you doing it? Part of nutrition, and one that can get overlooked, is hydration (aka how much you’re drinking).

While you’re training or racing, its really important to drink the right amount of fluid, particularly to maintain your body temperature.The last thing you want is for your body temperature to rise.

If you don’t drink enough, you’ll cook yourself and have a terrible run, at the least, and a trip to the ER at the worst.

I can think of a few races where I’ve felt fine, didn’t drink because I didn’t want to slow down through the stations, then paid for it with a wicked headache the rest of the day. I didn’t drink enough. This is a particular risk on hot days.

I’ll cook myself?!?

When you run (or do any exercise), your muscles will make heat, because they’re working hard. This heat flows to your core, and is then directed out into the environment. This is your body’s way of keeping your temperature just right.

How do we do that?

SWEAT. Sweat is your body’s mechanism to stay at the temperature it likes to be. If it’s hot and you exercise, you sweat more than if it’s cold. Makes sense, right?

Sweat is therefore more than just a slightly embarrassing sign you’ve been working hard (or badge of honor, which is how I like to think of it), it’s actually really important. If you stop sweating, you’re in big trouble.

Sweat is more than just water, it is also electrolytes. If you’re sweating a lot during your run, you may need to replace these. This is particularly the case in events more than 2 hours long. I’ll discuss electrolyte replacements in another post, but sodium (salt) is the main one to keep in mind.


How do you know if you’re drinking enough to keep your body happy?

hydration for runners

The average woman requires 2.7L of fluid per day. Don’t panic, you don’t need to glug down 2.7L of water to meet this!

20% pf your fluid is going to come from the nice, healthy foods you eat. Fruit and vegetables typically have a high water content, so you’ll get some of your fluid requirements from these.

You’ll make up the rest with fluid. Not just water, but all the things you drink. For general health, you don’t want to knock back loads of fizzy, juice or beer and proudly tally them towards your fluid intake. You want to be drinking mainly water.

When you exercise, you will need more.

If it’s a really hot day and you’re doing a really long run, 2.7L is not going to touch the sides. Research has shown that under these sorts of conditions, you may need up to 10 L!! (DON’T OVERDO IT THOUGH… THIS CAN BE JUST AS DANGEROUS AS UNDERDOING IT… I’ll post more about that another day).


Your aim: consume fluid at rates similar to sweating. This is all going to depend on the weather, the length of your run, and other factors.


Some tips:

    • Race day? Drink around 2 cups 2-3 hr before you start. This will help you keep hydrated before you lift a foot.
    • Do not restrict fluids while you run. Some women do this because they are worried about having to make toilet stops. This is a delicate one, but your hydration needs to take priority here.
    • Do not rely on thirst. Often we don’t actually feel thirsty until we are already dehydrated. Get to this stage and your performance is already impaired…bummer! Drink on a schedule so you don’t forget.
    • BUT: don’t drink more than 1 cup every 20 minutes. If you do, you can upset the balance of electrolytes in your body. If it’s not very hot, or you’re not an elite runner, a lot than this will be okay. I find that having some sips of water at each aid station works well.
    • Out for longer than an hour, and it’s not a race? You’ll need to carry your own supplies.


So don’t let yourself get dehydrated next time you head out for a long run in the heat, keep your fluids up and your performance just might be the best it has ever been. Your body will thank you, too.


Your running buddy,




image 1 by Rubbermaid Products, CC 2.0, https://flic.kr/p/bo7W8G, image 2 by Ron Kroetz, CC 2.0, https://flic.kr/p/pJVf5S

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