Muscle Cramps and Mythology

Contrary to what we’ve been led to believe, no one knows what causes muscle cramps. The common lore is that the culprit is electrolytes, but this is highly doubtful. Much of the sports nutrition industry, however, is based on this myth. The first product I recall ever seeing that strongly promoted the myth was called E.R.G. (Electrolyte Replacement with Glucose). I sold it in my running store back in the early 1980s (Foot of the Rockies in Fort Collins, Colo.). It was a powder that came in a tear-open container which you mixed with water and drank before and during the competition.

 

Others companies with similar products have taken up the electrolyte battle cry in the last 30 years. A boatload of money is spent by these companies to keep us convinced that we must take in sodium, chloride, magnesium, potassium and/or calcium during exercise or run the risk of cramping. Dehydration has also been linked to muscles knotting up during exercise. So sports-drink companies, especially, have had a field day with cramping. They’ve done a great job of convincing us with nothing to show as proof other than myth. In fact, there have been a number of studies over the past quarter century showing that electrolytes and dehydration are not the cause [1,2,3,4,5,6]. But the myth refuses to go away.

 

So why do athletes continue to believe that cramps are caused by low electrolyte concentrations? Part of the answer is that the myth has a long history. Around the start of the 20^th century dock workers were known to experience cramps while loading and unloading ships. Scientists back then took a look at the sweat of the workers who cramped and found chloride, which makes up about half of the salt in sweat. Without testing the sweat of the workers who did not cramp, they jumped to the conclusion that cramping was related to electrolyte loss and that heat and humidity were also involved. The myth was born.

 

It has been perpetuated over the decades by athletes who swear that when they take in electrolytes they don’t cramp. Or the opposite: When they don’t have access to sodium (or whatever) they do cramp. Sport is replete with such individual mythology. Athletes have their lucky coin, a spit before stepping into the batter’s box, a pair of socks worn when they’ve won or a mantra they must recite before the race begins. I once read about a famous American distance runner of the 1980s who had a lucky singlet and so wore it in every race – with great success. But when chosen to be on the U.S.A. team for international competition he had to wear the team uniform. His solution was to get a hotel room with a window that overlooked the race course and hang the lucky singlet in the window to ‘watch’ the race. I don’t recall how he did.

 

And there's more... I discovered about 10 years ago, after a great deal of research with n=1, that putting on my left shoe first is necessary to having a good race or workout. I’ve known this for a long time (and now you know it, too). To this day I always put my left shoe on first. And it’s worked. I have proof. Now it may not work for you, but it sure does for me.

 

Maybe putting on the left shoe and taking in electrolytes really does work. There’s this thing called the ‘placebo effect,’ which I’m sure you’re aware of so I won’t go into a discussion of it here. (If you’d like to know more about the placebo effect go here.)

 

So if it’s not a low electrolyte concentration or dehydration that causes muscles to cramp, what is the cause? Well, as mentioned at the start, no one really knows. There are theories. I’ll get into these in an upcoming post.

 

References

1. Brouns, F., E. Beckers, A.J. Wagenmakers and W.H. Saris. 1990. Ammonia accumulation during highly intensive long-lasting cycling: Individual observations. Int J Sports Med 11(S2): 278-84.

2. Maughan, R.J. 1986. Exercise-induced muscle cramp: A prospective biochemical study in marathon runners. J Sports Sciences 4(1): 31-34.

3. Miles, M.P. and P.M. Clarkson. 1994. Exercise-induced muscle pain, soreness, and cramps. J Sports Med Phys Fitness 34(3): 203-216.

4. Miller, K.C., G.W. Mack, K.L. Knight, J.T. Hopkins, D.O. Draper, P.J. Fields and I. Hunter. 2010. Three percent hypohydration does not affect the threshold frequency of electrically-induced cramps. Med Sci Sports Exerc March 2010 [epub ahead of print].

5. Schwellnus, M.P., J. Nicol, R. Laubscher and T.D. Noakes. 2004. Serum electrolyte concentrations and hydration status are not associated with exercise associate muscle cramping (EAMC) in distance runners. Brit J Sports Med 38(4): 488-92.

6. Sulzer, N.U., M.P. Schwellnus and T.D. Noakes. 2005. Serum electrolytes in Ironman triathletes with exercise-associated muscle cramping. Med Sci Sports Exerc 37(7): 1081-85.

Comments

[Brian McDowell]

Why am I cramping then, Joe? I stretch, do yoga, warm up, warm down, eat well, read "Going Long"... but I keep getting calf cramps when running. Ironman Lake Placid is only a few months away and I'm getting desperate...

[Joe Friel]

Brian M--Wish I could help, but nobody knows. I'll dscuss more theory soon.

[Brian M]

That would be great! Thanks for the reply.

[Jeff]

Brian M.

Try moving your cleat back on your shoe as far as possible. This minimizes calf recruitment on the bike. I haven't cramped a calf since I've done this.

[rich]

So are electrolyte drinks, tablets or gels necessary at all?

[Joe Friel]

Rich--I tell my athletes they don't need electrolytes during execise, but if they want to use them there is no known downside. Gels are primarily used for sugar/energy.

[Barry]

Brian M, maybe you have inadvertantly found the cause for cramps. Could it be purely and overload/fatigue in the muscles that cramp. Find the right balance for yourself and you have found the cure?

[Toby T.]

So during a race, you only recommend water and gels? No gatorade? What about increased sodium intake days prior to a race?

[Joe Friel]

Toby--You can use G-ade or any other sports drink you like for shorter races. Why would you load up on sodium before race? To prevent cramping? Doesn't do it. To improve performance in some mysterious way? The myth surrunding sodium will last forever, I'm afraid. Those scientists in that early 1900s study are still affecting us.

[Claus Poulsen]

I get cramps during swimming. During cycling never, have occasionally experienced during a marathon race.
Is it typically during swimming that you get cramps?
During swimming I get cramps in the large muscles in the legs and in/under my feet.
Kind regards
Claus Poulsen, Denmark

[pauline s]

I get a horrible side stitch on the run in EVERY triathlon that I do, but I never get one in running races, why is this? (whether I drink on the bike or don't)

[Joe Friel]

Pauline - very strange. I have no idea why.

[Amy S.]

I find this post slightly confusing; while I understand that your research shows that electrolytes have not been linked to cramping, you do not expound upon the purpose of electrolytes during exercise. Further, all of your sports drinks contain some level of electrolytes. My question is this: if you believe athletes do not need electrolytes, why would you include them in your sports drinks?

[Joe Friel]

Amy S--Good question. Thanks for asking. I find no compelling reason in the reseach to take in electrolytes during exercise (with the possible excption of a small amount of sodium which appears to improve water transport across the intestinal wall). I've come to this conclusion in the last 2 years after reading considerable info on the topic. I designed my sports drinks 4 years ago and no longer promote them.

[Toby T.]

Well, I don't really prepare for cramps through my diet. I've always associated cramps more with conditioning because i would never get cramps, in any sport, until i've been at the activity for quite some time or i didn't train much for it (just an inference of mine). But sodium prevents things like dehydration and heat exhaustion i thought. Your body sweats it out, and it needs to be replaced particularly for longer events. That's why i thought sports drinks are so useful.

I think i'm confused because i get the feeling you're down playing sodium and other minerals and stuff all together.

[Joe Friel]

Toby--I am indeed downplaying their importance. That's my whole point. Sorry if I wasn't clear. Research out of the Univ of Cape Town shows they do not prevent cramps, deydration, heat-related stress or anything else related to performance in normally healthy individuals.

[Vibram Five Fingers]

Hi,What a great post! Thanks for article. Everytime like to read you.Have a nice day!

[Craig B]

what about just good ol' water, that seems to do the trick for me.

[creative recreation]

The opinions you provid are of grat help, I like your blog, thank you.

[harley]

Im with Joe on this one, since I stopped eating added sodium in october 07, I havent cramped since. Ive won 24 races, racing div 1 and ran a few marathons and in HOT conditions.. :)

Give it a few weeks for your kidneys to adjust to a low sodium diet, its just like getting used to new climate etc.

Its interesting to note that all my mates that have had hypotranemia have all followed a high sodium diet..

[jordan retro 4]

Four short words sum up what has lifted most successful individuals above the crowd: a little bit more.

[Kyle Kranz]

"Rich--I tell my athletes they don't need electrolytes during execise, but if they want to use them there is no known downside. Gels are primarily used for sugar/energy."

Would the downside be that you are increasing the [electrolyte] in your plasma and upsetting homeostasis. If your electrolyte levels become too high your thirst kicks in and you are forced to drink to bring your concentration back to homeostasis.