“My whole life I’ve had cramping issues, especially past two hours of endurance activity… I’m just scared at this point to do anything over two hours.”

That’s from an athlete I worked with, and it’s one of the most frustrating places to be. Another rider described the same pattern: “I’ll do good for about 50 miles out of the 80 to 100, and then I will cramp hard.”

If you’ve been there, you’ve probably heard the same advice over and over. Take more salt.

Why everyone blames salt

I think we always immediately associate cramping with salt. And sodium definitely is a piece of the puzzle. But it’s not always the only reason we cramp.

Part of the confusion is about what sodium actually does. A lot of people think its main job is to prevent muscle cramping, but its primary role is really fluid retention. Sodium helps you hold on to the water you drink, and that fluid does a lot of jobs, including getting your fuel where it needs to go.

So when someone cramps, sodium is a great place to start looking. It’s just not the only place.

Three suspects: salt, fuel or fatigue

When an athlete comes to me with cramping, I’m usually looking at three possibilities. Sometimes it’s one, and often it’s a mix.

1. Sodium and fluid

This is still the first line of defense, so it’s where I start, by looking at total sodium intake. If you’re losing a lot of salt and water and not adequately replacing them, eventually your body is going to be like, you know what, you’re done.

If you haven’t looked at this yet, start here:

• Salty Sweater or Heavy Sweater? covers how much sodium you’re likely losing and how to match your bottles to it.
• How to Calculate Your Sweat Rate at Home shows you how much fluid you’re losing in different conditions.

If you’ve dialed both in and you’re still cramping, it’s time to look at the other two.

2. An underfueled muscle

A muscle that’s running low on fuel can cramp too. And this can happen even when you’re eating.

Even though you’re taking in carbs, they may not be getting to the right place in time. That can be because you’re dehydrated, so there isn’t enough fluid to move them along, or because of the type of carb you’re using. The fuel is in your pocket or your stomach, but it isn’t making it to the muscle that needs it.

That’s also why cramping sometimes shows up alongside a sour stomach. If you can’t digest what you’re taking in, your muscles aren’t getting it either.

3. A tired muscle

Sometimes a muscle cramps simply because it’s tired.

Think about professional football players. They’ve done this for years and years, with every resource available to them, and they still get muscle cramps in the second half of games. That isn’t because nobody handed them salt. It’s because they’re tired.

One athlete told me about the first time they had really vicious cramps: “It was only a three-hour race, but it was full gas the whole time.” Three hours isn’t an especially long race. But all that power output, held the entire time, pushed their muscles harder than they were used to. That kind of fatigue can cause cramping on its own, even with sodium and carbs right where they should be.

When it’s all three at once: the foggy morning

One athlete cramped badly in a race that started out foggy and cool. As they described it, it was so socked in in the morning, and then it just got hot.

That’s a setup for cramping from almost every direction. When it’s foggy, you’re not really thinking you need to drink a lot. So you drink less, which means less fluid and less sodium, right when the day is about to heat up. Then the heat hits, sweat rate climbs, fuel stops moving as well, and you’re pushing hard the whole time.

No single thing caused that cramp. It was the conditions, the fueling and the effort all stacking up.

How to troubleshoot your own cramps

One athlete asked me what the probability was that just getting carbs and sodium right would solve their cramping, and what we’d do if it didn’t. It’s a fair question, and it’s exactly why a little detective work helps.

1. Write down what actually happened. Next time you cramp, get specific. Something like: I started cramping at 75 minutes. I drank this many bottles. I had this much food 90 minutes before the ride. It was this hot. Understanding your routine is what shows you what led to that cramp.

2. Start with the amounts. More times than not, dialing in total salt and carbohydrate intake is a great starting point. Are you getting enough sodium for how you sweat? Are you getting enough carbs per hour for how long you’re out there?

3. Then look at the sources. If the amounts look right and you’re still cramping, look at what you’re taking in. Is it sitting well? Is it actually getting digested and absorbed, or is it sitting in your stomach?

4. Then look at the effort. Did you go out way harder than you’ve trained for? Was this the longest or hardest effort you’ve done in a while? You’re training for a 4-hour effort. You’re not going to just do 1-hour sessions to get ready for it. Longer training days also build up the fueling and hydration your body can handle, which helps with all three suspects at once.

The bottom line

Cramping is often a salt problem, but not always. A muscle can cramp because it’s low on sodium and fluid, because it’s underfueled, or because it’s simply tired, and on a hard race day it’s often a mix of all three.

Start with your sodium and carbs, because that’s where most athletes find the biggest win. If that doesn’t fix it, look at what you’re taking in and whether your training matches the effort you’re asking your body to do.

If you keep cramping even after your fueling and hydration are dialed in, it’s worth checking in with your doctor to rule out anything else going on.

If you’d like help doing that detective work, looking at your sodium, your carbs and your race-day plan together, that’s what we dig into inside the Gravel Performance Nutrition Course and in 1:1 sessions.