Cramping Science

I know it has been talked about on the podcast several times, I believe Chad had put many of the pieces together but wasn’t completely sure on the exact science of cramping.

According to Ben Greenfield in his latest podcast cramping is rarely caused by mineral dependencies or dehydration (which we already knew), but that it is actually caused by a protective mechanism called an “alpha motor neuron reflex”. Basically your body is cramping to protect it from tearing or ripping a muscle.

He states the way to reverse the cramp is by tasting something incredibly salty or incredibly spicy. We sort of knew this already but the mechanism is all neural based as there is not enough time for the body to absorb whatever you are taking. The taste alone causes a “motor neuron reflex” which cause the cramp to release in about 20 seconds.

Podcast can be found here:
Discussion on cramping starts at about 2:15.


I only can say, I use to stay hydrated, clear orine colour and I take some electrolytes during hard workouts and races or in hot summer when you use to sweat a lot.
The second step is to get accustomed your body to the same efforts you’ll do during races or friends rides. If you stay fit you won’t have cramps or al least you’ll reduce the risk to suffer one.

All that in most cases, maybe there are some use to have some cramps despite all before written.

I’ve started taking a broad spectrum magnesium nightly (I use the one from pure vitamin club); and I’ve been taking a electrolyte tablet (endurolytes or similar) before each trainer session and it’s cut way down on the cramping. I’ve also been keeping a big thermos of cold water handy thu the day.

If you’re interested in reading more about cramping, the following has a great series of articles:

It’s a little long, and a little technical at times, but is worth the read.

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There’s a bunch of good published research on exercise-induced cramping, much of it by Schwellnus (see here, and here).

From what I’ve read, cramps seem to defy conclusive recommendations. There are numerous theories regarding why they occur, and each seems to have decent anecdotal evidence but not a whole lot more. Then again, none appears to have been conclusively disproven, either. Which is to say, while one thing (hydration, electrolytes, nerve signaling) may not help everyone, it just might be the thing that helps you, so there’s a big potential benefit to trying things out in an orderly way to zero in on what helps.

In my case, I tried HotShot and it had zero effect. Increasing carb intake (up to 90 g/hr) and fluids (0.5L/hr in mild temps) seems to have helped quite a bit. Off-the-bike stretching and core work also seem promising, especially doing movements that induce the types of cramping I experience on the bike. My ability to do these without cramping increased significantly in only a few sessions. It all relates to (1) reducing the fatigue to which cramp-prone muscles are exposed; and (2) increasing the fatigue they can withstand before cramping.

Curious to read what others have tried, and with what result.


This is my first post on this forum. I’ve read up on cramping and like most I’ve used the “Juices”, Pickle Juice and HOTSHOT. I ran out of these products in the Whiskey 30 MTB race a couple years ago and had an epiphany, if the “Juice” mechanism is neurologic then perhaps biting my tongue will produce the same outcome.
Guess what, it did! When I first sense a cramp coming on I bite my tongue. Not in such a way to cause injury. I carefully place my tongue between the overlap in my front teeth and squeeze. I can actually modulate the onset of the cramp so that I can ride through it.

This very interesting and definitely reflects my experience with cramps. Everyone always used to bang on about hydration to prevent cramps, but for me hydration was never a factor. I could do an all-day ride in hot weather and be measurably lighter a the end of the day (up to 3kg) due to dehydration, and never cramp or have performance issues.

My cramps would always be caused by excessive high-intensity efforts, well above what I was conditioned for. It always felt like a build-up of muscle damage was the triggering factor. For example, I cramped in the final sprint of my race last week. It was only a 50km race in cool weather, nowhere near long enough or hot enough for me to become badly dehydrated. But I had done a heavy squat session during the week and failed to recover properly. My legs didn’t feel great, and at the end when I asked for maximum power they said no and shut me down.

It does feel like a protective mechanism IME. I’ve always been waiting for the science to catch-up, because I’ve never believed the hydration explanation.

I might try the salt thing, but I think I might be better off just listening to my body. If I cramp it’s because I need to improve to be able to handle the workload. The exception to this would be during an A-race.

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