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.

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.

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