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Close-up on a cyclist’s legs while pedaling on a ride

The 3 Biggest Causes of Leg Cramps While Cycling

It comes on unexpectedly, and it comes on fast. You’re enjoying a weekend ride when, out of nowhere, a searing pain shoots through your leg. You can hardly pedal enough to pull off the side of the road, and you’re doing everything you can not to scream.

You’ve been hit with a leg cramp — the scourge of many cyclists. More often than not, leg cramps hit late in the ride, after you’ve been working your legs for a long time. Aside from causing excruciating pain, they can leave your calf, thigh or quad feeling like it’s tied in a knot, making it difficult to finish your ride.

Developing leg cramps while cycling can ruin a ride in a matter of seconds, leaving you sidelined and unsure what happened. This ride didn’t seem so different, you think. Where did this come from? There are many reasons they happen, but Coach Darryl MacKenzie gave us the scoop on the three biggest causes of leg cramps while cycling and how to prevent them. Even better, he’s got the magic pill for how to stop leg or calf cramps during your bike ride.

You Pushed Yourself Too Much

This is the most common cause: You simply tried to go too fast or too far compared to your typical workout over the last six weeks or so.

Let’s say you’ve been riding a 30-mile ride at 14 miles an hour, but you ride with a new group that’s going 45 miles at that same pace. Or they’re going 30 miles at 16 mph. Either way, there may be a leg cramp in your future.

How to prevent it

This may seem obvious, but you have to lessen the strain you’re putting on your muscles since they’re not used to it yet. If you change your pace or distance, you’ve got to adjust the other variable accordingly. So, if you are going farther, then slow down. Or if you’re going faster, shorten your ride. Don’t push it too hard.

You’re Dehydrated

Dehydration is a very common cause of leg cramps while cycling as well, and it’s especially common on long, hot rides. Ultimately, you didn’t drink enough, you’ve been sweating a lot, or both.

You may not realize just how much water you can sweat out while cycling. On one particularly hot ride, Darryl recalls losing a full 5.3 pounds from the start of the ride to the finish. That’s a lot of water to lose, and your legs will let you hear about it.

How to prevent it: 

Prepare to stay hydrated. That means not only drinking a lot before the ride but having a sports drink with you for rides longer than 90 minutes. We’ve talked about how important this is for preventing bonking, but it’s also critical for hydration. 

“The hotter it is, the more you have to drink,” says Darryl. So check the weather on your ride and bring a few bottles if it looks like a hot one. Coach usually packs a variety of flavors and rotates them so he doesn’t get bored with any one kind. Do what you can to make yourself want to drink more throughout the ride.

You’re Short on Electrolytes

Electrolytes — minerals such as sodium, potassium and calcium — are essential for your body in many ways, not the least of which is muscle function. When you're low on them, muscles will stiffen and cramp much more easily. 

As you sweat, you lose electrolytes rapidly. And, again, the longer and hotter your workout, the more you’ll lose. Darryl has even seen his gloves turn white with sodium after sweating heavily on a ride. That’s another sure sign that leg cramps are just around the bend.

How to prevent it: 

How do you do your part to prevent this common cause of leg cramping while cycling? The first thing you can do is to stock up on sodium in the few days before your ride. This will give you a full supply of electrolytes to start out. 

While cycling, your sports drinks should replenish your electrolytes as you go, but you can bring along electrolyte pills that give you a boost, as well.  

When You Can’t Prevent It — There’s a Magic Pill 

Yes, you read that right. In this case, there actually is a magic pill. Sometimes, you can do everything right and you’re still going to get a leg cramp. Even if you’re following all of Coach Darryl’s other advice, you should be prepared in case it happens.

First, when a cramp starts, stopping the pain will become your highest priority. The best approach is to quickly lengthen the affected muscle. If it is the calf muscle cramping, for instance, lengthen the muscle by lowering the heel and raising the toes. Keep stretching it until the pain stops. In some cases, you can do this while standing on the bike, but oftentimes you’ll need to stop and take time to stretch and even massage the muscles a bit.

The magic pill, though? Tums. As soon as you feel the first tingling of a leg cramp, pull off the road and pop two of them. You want to slowly chew them and keep them in your mouth as long as possible. (You’re probably feeling as skeptical as Darryl was before he tried this, but in his experience, it takes effect within seconds.) 

Tums are rich in calcium carbonate, which is one of the best ways to quickly absorb calcium (one of those key electrolytes) and get your muscles firing freely again. Coach never goes on a ride without them, and he keeps them by the bedside for those dreaded nighttime cramps, too. Note, though, that you should only take Tums when a cramp is actively ongoing, not to prevent future cramps.

Leg cramps affect every cyclist differently. If you’re lucky, you never have an issue with them. But, if they’re a nagging problem for you, now you have a few tricks up your sleeve for next time. 


You can find more insights from Coach Darryl over at his website.