Why you get Muscle Cramps While Running, and What to do About It

You know what really sucks? When you’ve been training for months and months for a marathon, start the race, feel great, then between miles 18 and 22 your legs stop working. You know what I’m talking about. Those muscle cramps while running, the kind that feel like someone placed vice grips around your quads, glutes, hamstrings or calves. It makes you run like a stick person, teetering and tottering, and desperately trying to stay upright.

I have experienced this plenty during my marathons. In each case, the cramps showed up and it was a slow, death march to the end. Each time, I cursed myself, thinking if only I had done a better job hydrating, surely I would have done better.

As it turns out, research does not support the theory that poor hydration and/or electrolyte deficiency is the culprit of muscle cramps while running. If you think about it, the last time you got really bad cramps, why were they only in your legs and not also your arms?

As I have mentioned, my last marathon didn’t go so well. In part, this was because around mile 21, I started cramping, and had to slow by almost two minutes just to keep moving. Now that I’m training again, I wanted to understand what was really going on. I did some digging, and found some really interesting stuff!

Below is a quick summary and three suggestions about how how you can (hopefully) avoid muscle cramps while running. Like much advice on this site, it will involve some hard work, but well worth it when you cross the finish line cramp free!

Why you get Muscle Cramps While Running

If you are someone who gets cramps in the middle of the night, or have another medical situation, that’s not this. For our purposes, exercised-assocaited muscle cramps (EAMC), are any sort of agonizing cramp that hurts your running performance. Andrew Buskard wrote a great article called, Cramping in Sports:Beyond Dehydration. In it, he reviews the research that points to the myth that cramping is caused by dehydration. He also explains an alternative.

Before diving in, there are two key exercises physiology terms you should know; Golgi tendon organs (GTO’s) and muscle spindle fibers.

Muscle spindles are sensory receptors in the belly of muscle tissue that respond to stretch in the muscle by reflexively contracting it to prevent hyperextension. GTOs are found at the musculotendinous junction and respond to high degrees of force in the muscle by inhibiting further contraction.

Our muscles contract when a signal from the brain tells them to. The muscle spindle fibers and GTOs work together to contract and release, over and over and over. When muscles fatigue while running, this process breaks down. Jeff Gaudette of Runners Connect describes the breakdown this way,

…when the neural mechanisms that are supposed to inhibit muscle contraction are depressed and the chemical and electrical synapses that fire the muscle fibers is enhanced. The result is an intense, sustained involuntary muscle contraction.

In other words, the GTOs fail to say, “hey, it’s time to release and start over!” A return signal is never received, and that is what is causing the pain.

3 Ways to Prevent/Reduce Cramping

It is impossible to totally prevent all cramping forever. But, while cramping during an intense race is common, it is not inevitable. Knowing the real cause of your running induced cramps is helpful because now you can do something about it! The first time I had muscle cramps while running a marathon, I thought the answer was to hydrate more. That really didn’t work, as I had virtually the same level of cramping even after sucking down more gu and water.

Since cramping is caused by a breakdown in the neurological transmissions caused by extreme muscle fatigue, there are a few things you can do to prevent this fatigue from happening, or at least making it less likely.

Strength Training – I have talked about this a lot because it’s important! Find a good strength routine and make sure you spend time doing it along with your running. If you need some specific instruction, here is the program I use and recommend. Not only will this help the cramps, but it will make you faster and less injury prone.

More Runs at the Pace you Plan to Race – The more training runs you can get in at the pace you plan to race, the better. This will probably also help you set a PR. Since these types of muscle cramps while running usually happen during marathons, you will want to incorporate speed into a bunch of long runs. Something like 10+ miles at your goal marathon pace. At peak training, for me, this has meant a long run of 20 miles, with 15 miles at goal race pace in the middle.

Unfortunately, people too often simply don’t run enough overall volume to really prepare their bodies for the rigors of the marathon. Plans that have you only running three or four days a week, and stopping at or below 40 miles a week, will get you to the finish line, but not without a lot of pain.

Work on your Running Form – When form breaks down later in a race, cramps are more likely. This is more difficult to figure out on your won, and I would recommend finding a coach to help. If that’s not an option, you can checkout this online course as well. It is an investment into your future.

If you do get muscle cramps while running (at whatever distance), the best advice I’ve seen is to slow your pace or stop. This can get the proper messages firing again, and release the cramp. Passive stretching also works, as it “reboots” the “computer” and brings the GTOs back to life. It is able to recognize the high levels of tension in the muscle, and it goes away… at least that’s the theory.

Your Cramps

When I started cramping around mile 21 of my last marathon, it was because I was running too fast for where my training was at. Being realistic about where you’re at (versus where you want to be), can go a long way. Had I slowed down, I probably wouldn’t have cramped, and may be running at Boston now.

What works for treating your muscle cramps while running? Some say drinking pickle juice helps, which science says it does, but I have yet to meet somebody who has any on hand when it really matters.