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How to prevent muscle cramps while running

My tried-and-tested essential tips will help you stop getting those painful running leg cramps that's so common among runners.

Nearly all runners have suffered this sharp leg muscle pain during their runs at some point. You know the one – that uncontrollable muscle spasm that normally happens in your calf or other muscles in your legs or feet, while you’re running.

This is something I suffered from a lot, especially on fast or long runs including marathons and ultramarathon races. But, you can get calf cramps and other leg muscle spasms from running slowly, or while walking, too.

In this post, I explain what running cramps are, what causes them, and, most importantly, my tried and tested simple tips to help you prevent muscle cramps while running.

My experience with debilitating leg cramps while running

When I got more seriously into running, I didn’t really know my body’s limits. Well, I have been known to push it and run fast and hard during my training cycles! I was often left wondering, why do I get cramps when I run?

This was especially true when I started to run more in hot weather, and run more hills, longer distances and technical terrain during trail runs, and it happened more often.

How to prevent muscle cramps while running - why do I get muscle cramps when I run?

All these factors required more from my muscles, and as a result, I had to learn how to be more efficient when running for longer on the trails to minimize muscle fatigue and avoid cramps from causing pain in the last stages of my runs and races.

The problem with running hard and fast is that your body is rapidly depleted of salts and your electrolyte balance gets offset (especially in hot weather), and before you know it, you’re hobbling to the finish with the most painful spasms, usually in your leg muscles, not to mention a bruised ego.

This was so frustrating as they seemed like such an easy thing to avoid – because after all, not everyone has this issue. But fear not – because there are some easy ways to prevent them.

What are running cramps?

Running cramps are a common type of muscle cramp that can occur while running or exercising.

They are caused by a build-up of lactic acid in the muscles, which can lead to a sudden, sharp pain and leg spasm, which can be so bad that you have to stop running until it goes away.

These leg cramps often happen in your calf muscles but can also affect your quads, hamstrings and other parts of your leg and foot.

How to prevent muscle cramps while running - why do I get muscle cramps when I run? They're painful leg spasms running and how to avoid them.
Those running leg cramps will make you stop running, and probably pull a face a bit like this.

Why do I cramp so easily when I run?

The cause of this type of leg muscle pain is very different to why you may suffer from a stitch when running.

Dehydration and not retaining enough electrolytes, as well as excessive muscle overload (and associated fatigue) are possible causes. I know they were for me – which was helpful as I then learned how to stop the problem.

This isn’t an issue limited to new or inexperienced runners: even experienced athletes running too fast in races, with insufficient sports nutrition or preparation can suffer from them.

Dehydration and electrolyte loss

If you tend to sweat a lot when you run then you may have significant electrolyte loss through sweating, especially for longer runs or running in hot temperatures where your fluid intake is insufficient.

Losing these essential salts from your body is often attributed to the main cause of cramps, especially if your body starts to move into those early stages of dehydration.

Muscle overload and fatigue cramps

In addition to poor stretching before you start your run, dehydration can speed up muscle fatigue. It can affect circulation and the removal of lactic acid from your muscles.

They can’t work efficiently if you’re not appropriately hydrated, so specific muscles can get overloaded and overly fatigued, which can both contribute to the spasms you may experience while running.

How to prevent muscle cramps while running - why do I get muscle cramps when I run? They're painful leg spasms running and how to avoid them.

How do I stop my legs from cramping when I run?

Ok so now you know what causes them – here’s how to stop your calf (and other leg and foot muscles) cramping.

  1. Dynamic stretching before a run
  2. Pace yourself properly
  3. Drink electrolytes
  4. Take salt tablets with you

Dynamic stretching before a run: warm up properly!

It’s so important to do dynamic stretching before you run – this warms up the muscles so there’s less chance of you straining them when you start running. The warm up gets circulation and blood flow going around your body.

Straining your muscles can trigger the onset of muscle cramps from running, especially when your body begins to reach the point of fatigue.

Doing a proper warm up before your run is even more important when you are running in the cold.

A few classic dynamic stretches to try to help with your pre-run warm-up are:

  • butt kicks (great for the hamstrings)
  • leg swings
  • alternating walking lunges (great for the hips and quads)
  • skipping

If there are specific muscles that are usually affected, take the time to focus on getting them properly stretched and warmed up.

I generally spend 5-10 minutes before a run, gently running around and then having a good ol’ stretch.

If you’re not familiar with the best running stretches to do before and after running, visit our best running stretches guide, which includes tips and video demonstrations of our favorite pre- and post-run stretches to do.

Alastair Running in Bend Oregon Why you should take your phone running
Judging by the lean into the curve, I may have been guilty of running too fast on this run.

Pace yourself properly

I used to run like a greyhound out the gates when a race started, with a very fast pace that I tried to sustain for as long as possible. That’s all very well if you’re running a 5k, but anything beyond that and off-road needs a different approach.

I also tend to sweat a lot when running at an intensity of around 65% or higher. This has a handy purpose of cooling you down, but it also drains you of your salts and dehydrates you.

If you have lost a lot of sodium (for example, from sweating), then you are at greater risk of getting leg cramps while running, as the leg muscles tend to be working the hardest when you run.

Drink Electrolytes

When running a long race at a high intensity for anything less than 2 hours, and I know that race organizers will provide electrolytes at aid stations, then I only take water in my running hydration pack.

If electrolytes aren’t provided or I know my race or training run is going to last more than two hours then I’ll take my own sports drink mix in one bottle, and have another soft flask for water.

I always run with a hydration pack which takes two 500ml soft flask bottles. This works perfectly for this scenario.

The reason for having two bottles, is that sometimes you just don’t feel like drinking your salt drink mix, but require hydration. Being able to satisfy the need for pure water is a must when on the trails.

Here are a few suggestions for getting the salts back into your body:

Skratch Labs Hydration SPORT Drink Mix

Skratch Labs Sport hydration drink mixes are designed specifically to help rehydrated during endurance efforts such as long runs.

Try pickle juice

You may have heard of pickle juice as being a potential cure. Pickle juice is known to help with running cramps and is another option you can try, as it can help replenish those lost salts. Learn more about how pickle juice can help with cramping.

Tailwind Nutrition

The Tailwind electrolyte and carbohydrate mix that I’m currently enjoying is Tailwind Nutrition (unflavored). It helps provide energy (carbs) as well as salts.

I have tried many different brands, and this one is particularly great for sensitive stomachs.

If you’re not sure which to go for, then I advise you to try some out and see what works best for you. It really is a trial and error process when it comes to sports drinks and nutrition, as everyone’s tastes and needs differ.

saltStick Caps - Trail & Kale - wm-min

Take salt tablets to help prevent leg cramps while running

Salt tablets were a bit of a revelation when I first discovered them. They are my ‘get out of jail free card’ when the first three steps fail me and I still manage to get muscle cramping when running long trail running training runs and races.

The brand of salt tablets I use most often is called SaltStick Caps, also just refered to as Salt Stick.

They’re basically capsules filled with salts and electrolytes (and no carbohydrates such as sugars, lactose, and fructose).

Whenever I feel like muscle cramps are imminent, I take one of these tablets and within 5 minutes, the feeling is completely gone.

I find I can keep instances of muscle cramps from running at bay by continuing this process throughout my race. Please consult the bottle guidelines to make sure you don’t take too many during a 24-hour period though.

Use running gels with electrolytes

While many running gels are primarily designed to provide you with sugars to give you energy when running, a lot of the best running gel brands also make gels containing added salts to help replenish those you’ve lost through sweating when running.

Head over to our list of the best energy gels and chews if you’re looking to try some out and see if they’ll work for you!

By applying a combination of these steps, I have managed to prevent muscle cramps from running all but the most challenging of long runs and ultramarathon races.

If you are a runner who has been suffering from leg cramps, I hope that by trying out these tips you can have the same success in preventing these painful leg spasms and can concentrate on performing to the best of your ability – and importantly, enjoying your running and racing!

*Disclaimer – We are not medical experts, and all information in this article has been gathered from our experiences on the trails and sourced from our own research on the internet.

You should always seek the advice of your physician or other qualified health provider, with any questions you may have regarding personal health or a medical condition, including diagnosis and treatment for your specific medical needs.

As the founder of Trail & Kale, and seasoned marathoner & ultrarunner, Alastair loves bringing our readers independent running shoe reviews and gear insights to help you run your best. Learn more about Trail & Kale here.


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