Dear Mark: Muscle Cramps and Parasympathetic Overtraining

crampus finalFor today’s edition of Dear Mark, I’m answering two questions from readers. First one comes from Debbie, a prolific hiker and backpacker who can’t seem to shake terrible thigh muscle cramps during steep climbs. She’s tried all the conventional advice. She’s taking electrolyte tabs. She’s staying hydrated. Nothing works. What does? And then, Brad wonders about parasympathetic overtraining, a type of overtraining you don’t hear much about. What does it mean and how should he respond?

Let’s go:

Hi Mark,

I do a lot of hiking and backpacking in Southern California and the Sierras. I’ve recently begun to experience excruciating thigh cramps on steeper hikes, especially on the step-ups. I always carry electrolyte supplements and take them before the hike, during the cramp, and afterwards, so I don’t think it’s an electrolyte problem. I stay hydrated throughout the hike. I read recently that cramps are really caused by a nerve dysfunction and that spicy or intense foods like ginger, cayenne or cinnamon (there is at least one product on the market) taken before or during a cramping episode can relieve the symptoms. I was hoping you could comment.

Thank you!


Ah, man, muscle cramps during exercise are the absolute worst. And so frustrating: the literal loss of control over your usually trusted movement allies when you need them most. Yet according to the best research we’ve got, neither electrolyte replenishment nor hydration status actually affects cramping. It’s weird and unexpected, I know, but that’s what the research says:

In one study of Ironman triathletes, running speed and previous history of cramping predicted muscle cramps, not electrolyte balance or hydration status.

Another study in distance runners also found that neither electrolyte status nor hydration could predict cramping.

What does seem to cause cramps?

Altered neuromuscular control.

The more you use a muscle (and the harder you push it), the more fatigue sets in. Fatigue disrupts the balance between excitation of the muscle and inhibition of the muscle; it increases the former and decreases the latter. Tired muscles are more likely to go into excitation mode—to rapidly and repeatedly contract. That’s a cramp.

Pickle juice works against cramps, but not because of electrolyte repletion. It actually has no real impact on hydration or electrolyte status, and drinking it resolves muscle cramps faster than the gut can absorb it. TRP ion channels in the oropharyngeal region (tongue/mouth/throat) react to something in the pickle juice—probably the vinegar—and short-circuit the excitation of the muscle. Pretty cool.

Other TRP ion channel activators are found in cayenne pepper, ginger, and cinnamon, and researchers have created a blend of extracts from all three plants that shows efficacy against muscle cramps. It’s called Hot Shot.

That’s not to suggest electrolytes and hydration aren’t important. They are, especially when you’re hiking or training or otherwise exerting yourself physically. Adding salt to your water before a session does improve performance, particularly in warm climates. You could make my blackstrap molasses electrolyte drink mix. It’s not exactly delicious, but it does the trick. Salted OJ is also good. Tastes like Sunny-D, only with actual fruit. But electrolytes and hydration clearly have little to do with muscle cramps.

If you have access, try salgam. It’s a Turkish drink made of fermented black carrot juice, sometimes with added pepper juice. I only know about it because one of my training partners from way back in the day was always into obscure ferments from other cultures. Beet kvass, kombucha, coconut water kefir. These are relatively common today, but back then they were totally new and very weird. One day on a run he was toting this bottle of black liquid around, touting its benefits. Feeling parched, I asked for a swig of what turned out to be salgam. It was salty, briny, vinegary, and incredibly refreshing. It revitalized me.

You may not be able to find it. You might have to make it. And it’s not quite Primal: traditionally, bulgur wheat is added to aid in the fermentation, though likely not in significant enough proportions to impart serious amounts of residual gluten (celiacs and the gluten sensitive should avoid). But I bet it would really work well against cramps, due to the acidity triggering the TRP ion channels.

Some other tips:

Stretch out the muscle currently cramping. If your feet cramp, pull your toes toward yourself. If your quad cramps, grab your ankle and pull your feet toward your butt.

Stay hydrated and keep using electrolytes. They can’t hurt and may provide a base layer of support against cramps, but aren’t any type of cure.

If you’re consistently getting muscle cramps, you might be hiking too hard and your muscles are protesting. Consider shortening the distance and/or the difficulty.

Good luck!

Hi Mark,

I’ve been monitoring my HRV every morning for a little over 2 months, mainly out of a curiosity to see if there are any trends I can use to my advantage. After paddleboarding the last 3 days in the heat (90+ in the northeast), my HRV indicated I was in an overtrained state with abnormally high parasympathetic activity. My hunger in the heat is usually less, however today I feel ravenous.

My questions are: 1) is there any research you’ve come across looking at the connection between parasympathetic activity and hunger levels? And 2) should I look at this as an opportunity to eat more today than usual and see some good results in terms of muscle growth and recovery?

Thanks for everything.


When most people discuss overtraining, they’re talking about sympathetic overtraining. That’s where stress hormones are high, resting heart rate is elevated, heart rate variability is low, sleep is awful (“tired but wired”), performance is bad, appetite is down, blood pressure goes up, and bodyweight (usually lean mass) drops. If you remain in that state long enough without doing anything differently, you progress to parasympathetic overtraining. That’s what happens when your sympathetic nervous system exhausts itself, when the adrenal gland just can’t pump out any more adrenaline and cortisol, when you’ve made your sympathetic nervous system so weak that the neglected parasympathetic pathway dominates.

It’s characterized by fatigue, a low resting heart rate (which can make people think their fitness has improved), increased appetite and weight gain, low libido, low blood pressure, and excessive sleep.

Parasympathetic is the “rest and digest” pathway, so it makes sense that you’d be hungry. Consider it your body’s way of telling you to chill the hell out, put your feet up, and eat some real food. Stay with healthy, Primal fare. Go lowish carb, as you won’t be doing much in the way of training and don’t need much glucose.

For exercise, don’t. Take a few days off from any real training. Instead, just walk. Hang out at the beach. Maybe go for a lazy paddle. Stay hydrated. Get some shade.

That’s it for today, everyone. Thanks for reading and take care!

About the Author

Mark Sisson is the founder of Mark’s Daily Apple, godfather to the Primal food and lifestyle movement, and the New York Times bestselling author of The Keto Reset Diet. His latest book is Keto for Life, where he discusses how he combines the keto diet with a Primal lifestyle for optimal health and longevity. Mark is the author of numerous other books as well, including The Primal Blueprint, which was credited with turbocharging the growth of the primal/paleo movement back in 2009. After spending three decades researching and educating folks on why food is the key component to achieving and maintaining optimal wellness, Mark launched Primal Kitchen, a real-food company that creates Primal/paleo, keto, and Whole30-friendly kitchen staples.

If you'd like to add an avatar to all of your comments click here!