“F@!k!! Not now. Is this really happening?” I was the lead female at mile 22 of the DONNA Marathon. “Come on legs. You trained for this. You can do it.” The pep talks and self loathing didn’t have any effect on the sporadic muscle spasms surging from my calves.
It was an unusually warm, humid day in Jacksonville. The fog that had protected us through the first half of the race had broken, the temperatures were rising into the high 70’s, and there was nothing but glistening pavement ahead.
This was my first experience with exercise associated muscle cramps (EAMC). At the time, I had no idea what was happening. The cramps were so jarring, I thought people could actually see the convulsions occurring in my legs. Somehow, through a slowed pace and likely horrible form, I held my first place position and made it to to the finish line… super dehydrated.
That was February of 2017. My last race was this October, the Chicago Marathon. It was not a hot day. I hydrated all week, took salt tabs the morning of the race, and stopped at every water station for water and/or gatorade.
The muscle cramps started at mile 19.
A lot of things went wrong for me in Chicago: poor pacing, a head cold that required a race morning neti pot (seriously, who invented that torture device?), some self doubt, and of course, muscle cramps. But, people seemed to be most interested in giving me advice on the cramping. “You didn’t take in enough fluids. It was humid, you were salt depleted. You should have had more nutrition.”
Because I’m a skeptic and generally question everything, I had a hard time believing this was the issue. So, after Chicago, I started searching for answers.
Let’s go back to where it all began… 100 years ago workers in hot and humid conditions of the mines and shipyards suffered from cramps. Mine owners and scientists were curious about the cause, so they conducted a study. As Joe Uhan notes in his article, “The study was tragically flawed: insufficient subjects, a lack of controls, and – most outrageously – completely failed to show any correlation between cramping and sodium. Instead, they found a single subject with low sodium in his urine. That’s it. Thus, our belief of salt and cramping originated from a urine sodium sample of a single study, of a single miner… who did not even experience muscle cramping.”
It’s from this hilariously absurd study that the electrolyte-imbalance-and-dehydration theory was born. This theory suggests that EAMC is related to the decreased concentration of electrolytes, particularly sodium and chloride, resulting from excessive sweating. This makes sense to me when we’re talking about mile 20 of marathon. HOWEVER, there is not a single study that shows blood electrolyte concentrations – including sodium – are abnormal at times of muscle cramping. On the contrary, four studies (here’s one, here’s another, yet another, and one more) have shown that cramping athletes have completely normal blood sodium levels. Also, if this was REALLY the cause, the cramping wouldn’t happen in a localized area (like the calves). You would be cramping everywhere. YIKES. So…
So, why are we all still on the electrolyte-imbalance bandwagon? Well, when the company that manufactures and sells sports drinks becomes the company who funds and performs much of the research on fluid and exercise… you can probably guess what happens. Feel free to read up on the Gatorade Sports Science Institute. I’ll leave my rant on that subject for another time.
There’s another legitimate reason we still talk about this theory… it kinda works, just not how we expect.
I remember the first time I saw pickle juice offered at a race. We had just finished the Baltimore 10 Miler and everyone was walking around with pickle pops. Some guy named Bob made them and they were called “Bob-sickle pops.” I kid you not. After questioning everyone sucking those down, I learned they were all the rage in running. They claimed to help with muscle cramps. This was life before marathons for me, so I kindly opted out. But this leads us to the famous pickle juice study…
In 2010, a study was conducted to test the effects of pickle juice and cramping. Researchers exercised a group to induce water and sodium loss and eventually exercise-induced muscle cramping. After the three conditions were met, one group drank pickle juice, a control group drank water and a third group did nothing. The study found that, a reduction in cramping occurred in under 35 seconds for the pickle juice drinkers and under 90 seconds for the water drinkers. I know what you’re thinking – “SEE, SALTY STUFF WORKS!” Well, you’re right, but since the effects took place so quickly, the pickle juice could not have actually changed the blood sodium or overall hydration levels. There wasn’t enough time for the stomach or intestines to absorb the salt or water.
So what happened? Most likely, the pickle juice triggered a neurological reflex, somewhere in the mouth or throat, that traveled to the brain. So it was a brain effect that reduced the cramping. This opens up the door to a whole slew of new theories and possibilities. Chief among them is the altered neuromuscular control theory, or the idea that cramping is coming from our nervous system’s relationship with muscle contractions.
This theory tends to get very science-y, but here we go – the Golgi tendon organ (GTO) and muscle spindle belong to the nervous system and function to influence movement. As our muscles fatigue, there is an increased firing from the muscle spindles to keep contracting while, at the same time, there is a lessened response from the muscle GTOs to relax. This combo leads to over-excited alpha motor neurons, and essentially, a cramp.
But, why is this happening in the first place, after running countless training miles, tough workouts and marathon-specific long runs? That’s the million dollar question. You may have guessed it from the title of this article, but our understanding of muscle cramping is that they are complicated and likely stem from multiple factors. In essence, muscle cramping is the perfect storm. It could be that you went out too hard in the first half of the marathon (check), allowed yourself to become overheated (hello, 190 HR at mile 10), or altered your gait because you were tired (check). More likely, it’s the lethal combo of all three.
A few other factors stand out in these studies. Runners who cramp tend to run hard, have “the habit” (aka: a history of cramping) and possibly pre-race muscle damage. Not exactly earth-shattering, or the best news for someone coming off cramp-disaster #3.
So, what do we do now?
From the pickle juice study, a new idea emerged that a neural reflex in the mouth, stomach or esophagus could quickly disrupt the alpha motor neuron, stopping the cramp. In other words, we can trick our brains into thinking we’re not actually dying. This discovery has led to the development of several new anti-cramping products, like HotShots. Do they work? Maybe. I personally haven’t tried them… yet.
There are lots of suggested strategies for the treatment and prevention of EAMC. However, most of them are anecdotal. We really need more studies to support any legitimate treatment options or prevention strategies. (Where you at, Nike!?) In the meantime, I’ve compiled my thoughts based on the research and studies I’ve read. Here’s my personal preventative plan:
- Placebos can have very real effects. If a salt tab, pickle juice or HotShots works, go with that and stop asking questions.
- Train hard and smart. When the demand you put on your muscles does not match up with the training you’ve done, you are more susceptible to cramping.
- Work on form, mobility, and range of motion. Muscles most affected by EMAC are those that are confined to a small arc of motion, in a shortened state, and used repetitively.
- Stretch. All the muscles. All the time. (but, mostly the ones that are affected by cramping)
- Strength train. It prevents injuries, helps you run faster by improving neuromuscular coordination and power; and it improves running economy.
- Hydrate and fuel well. Glycogen depletion and inadequate fueling can lead to premature muscle fatigue and increase your risk of cramping.
- Calm the F down. Cramping is a neurological phenomenon, like pain. Anxiety and worry about cramping may increase its severity.
- Smile or laugh, even if it’s fake. It’s proven to improve efficiency (and race day photos).
I don’t know what my next marathon will be, but I am really frickin’ determined to side-step these muscle cramps. I’m going to do all the things I always say I’m going to do, (stretch, strength train) but never actually do. And you can bet I’ll be that girl licking a salt block and fake laughing her way through the last 10K.
Resources and Studies
Exercise Associated Muscle Cramps – A Current Perspective Jun Qiu1 and Jie Kang1,2* 1 Human Performance Laboratory, Shanghai Research Institute of Sports Science, China 2 Department of Health and Exercise Science, The College of New Jersey, USA
Reflex Inhibition of Electrically Induced Muscle Cramps in Hypohydrated Humans KEVIN C. MILLER1 , GARY W. MACK2 , KENNETH L. KNIGHT2 , J. TY HOPKINS2 , DAVID O. DRAPER2 , PAUL J. FIELDS3 , and IAIN HUNTER2 1 Department of Health, Nutrition, and Exercise Sciences, North Dakota State University, Fargo, ND; 2 Department of Exercise Sciences, Brigham Young University, Provo, UT; and 3 Department of Statistics, Brigham Young University, Provo, UT
Br J Sports Med. 2004 Aug;38(4):488-92. Serum electrolyte concentrations and hydration status are not associated with exercise associated muscle cramping (EAMC) in distance runners. Schwellnus MP1, Nicol J, Laubscher R, Noakes TD.
Increased running speed and pre-race muscle damage as risk factors for exercise-associated muscle cramps in a 56 km ultra-marathon: a prospective cohort study. Schwellnus MP1, Allie S, Derman W, Collins M.