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Monday, November 19, 2007

Muscle cramp 'teasers'. . .

Apologies for the absence...and some muscle cramp 'teasers'

Ah, the joys of the University calendar! We must apologize for our somewhat lengthy absence - it has been 5 days since we last did a post, which I think is the longest break we've had since we began The Science of Sport in April earlier this year!

But we have good reason, for both Jonathan and I are both deep into marking and examination of undergraduate and post-graduate exams and theses at our respective universities. Though Jonathan and I both enjoy lecturing and find it very rewarding, when we reach mid to late-November, our disposition towards teaching changes somewhat, as hundreds of exam scripts and thesis work suddenly land on our desks for us to plough through! And funnily enough, the other work doesn't seem to realise it and let up!

So we do apologize for the break, but we're back now, hopefully with a bang, as we get stuck into a new series, this one on Muscle Cramps - Science and Fiction.

A follow on from fluids and dehydration

The series on muscle cramps is really an extension of our last series - Fluid Intake and Dehydration. In that series, we tried to explode some of the myths around drinking during exercise, describing how the prevalent "scientific" advice was in fact flawed (sadly, it's often fatally flawed). We looked at the claims and counter-claims and ultimately encouraged everyone to do the wise thing - listen to your body, and when it says you're thirsty, drink! But only then...don't let the fluid companies tell you that you're the only mammal too stupid to know when to drink by itself!

Introducing muscle cramps - some points to ponder

The muscle cramp story is similar, sadly. In South Africa, we have a host of companies who produce cures, preventative tablets, creams and liquids to help you avoid cramp. The premise, as was the case with fluids and dehydration, is that a cramp is caused by a depletion of some electrolyte - sodium, potassium, calcium or magnesium. All have been mentioned, and most often, it's sodium and magnesium that take the brunt of the blame.

We'll take a step by step journey through muscle cramps in the series. We'll tackle it in three parts:

  1. What is a cramp? Very brief history and overview of what we know, and how we know it.
  2. The electrolyte-dehydration-heat theory for muscle cramps
  3. An alternative view - evaluating the gaps in the theory
So that is what you can look forward to (or with dread, as the case may be!) over the next week.

Until then, here are some issues to ponder:

  • Despite the theory that muscle cramps are caused by electrolyte and fluid depletion, it has yet to be shown that people who cramp have lower electrolyte levels or are more dehydrated than those who do not. In fact, the studies have found that "Crampers" and "Non-crampers" have similar electrolyte and dehydration levels. Something wrong with that picture...
  • If cramps are caused by electrolyte and fluid depletion, which muscles would be most likely to cramp? Would it not be ALL the muscles, because you're losing electrolytes and fluid through sweat, so then all the muscle groups should be vulnerable...yet for some reason, we cramp in the muscles we actually USE. Again, something out of place there.
(Some of you may already have a counter to these points, saying that what is happening in the muscle is not necessarily what is happening in the blood - we'll tackle that one for sure)

  • And then finally, if you are reading this before heading off to bed, we hope that you don't experience the dreaded "Night cramp", which we're sure most of you have had at some stage. You wake up in the night, and feel a slight twinge, usually in the calf. Your first impulse is to point your toe, and when you do that, what happens? You may know that if you do this, you'll be writhing in agony instantly! Instead, what should you have done? The answer is you should stretch the muscle - stretching is the quickest way to get rid of cramp. Now, how do we explain that one according to a heat-electrolyte theory?
The answers to follow, so join us then!



Anonymous said...

Dear Jon/Ross,

I was beginning to wonder where you guys went.

In case you are running short of other ideas, is there anything scientific myth-busting related to plantar fasciitis that would be interesting for you to research?

I did a little "web-research", and like most topics within running, it seems there is nothing short of the full spectrum of advice:
- while one says to ice the injured area, another says hot foot baths; at least another one says to combine and alternate hot and cold
- while one says to stretch, another says stretching may cause further damage
- while one says wear proper fitting shoes with adequate support or cushioning, or even orthotics, another says they can mask running defects, and you should wear minimalist shoes, (or even run barefoot), in order to learn proper technique

I guess I can see the truth in all of them.

Just a suggestion, in case you can find a related theme. Looking forward to you follow-on cramp series.


Ross Tucker and Jonathan Dugas said...

Hi Ray, and thanks again for always visiting us here at The Science of Sport.

It sounds like you have been afflicted by plantar fasciitis, and if that is really the case I am sorry to hear that. . .it can be a real nightmare to rehab and recover from.

There are lots of posts we can do about these topics, all relevant, and so thanks for asking these questions! It is reader comments like yours that will keep the info here fresh and meaningful to the audience.

Kind Regards,

Anonymous said...


Thanks for the response. Indeed I have a mild case -- from what I've read it can be a lot worse, and a pain to get rid of -- which I believe I can manage with some rest, massage, and stretching.

I found the process of "web investigation" enlightening. As I said, there is a broad spectrum of information and opinions how to deal with it.

There are even a couple of businesses which sprang up around it -- for $37 I can buy a CD and get rid of it in days. That costs less than a visit to the doctor.

If stretching and rest doesn't work, I will find a Chinese doctor for some acupuncture, or buy a "footlog" and study reflexology.

It just seems like a domain ripe for scientific scrutiny. I'm aching to hear anything you have to say.


PS: All puns intended

Ross Tucker and Jonathan Dugas said...

Hi Ray,

Your point about remedies that are cheap and affordable is actually quite an important one.

In all of science and research, we have the "placebo effect." In the best scientific studies, we must control for this effect, which means we must have an experimental condition in which the person thinks they are getting a treatment, but really all they are getting is nothing.

The really interesting thing, and one that we often joke about, is that the placebo effect is, indeed, a real effect! So if someone thinks taking a swig of special oxygenated water makes them run faster, then it probably will.

And often times it really does make them run faster. Can we explain it by looking at the physiology? No. Yet they perform better. That is the placebo effect.

Most---and I use that term carefully---of these remedies are harmless substances. They rarely contain any sophisticated ingredients, which is why they can flog them so cheaply. The point is that they are probably not doing anyone any physical harm. . .instead it is just financial harm!

But providing the product is not harmful for the person, it is ok to take it. Will it help with their cramps/performance/aches/pains/etc? Perhaps, but again, as long as it is not harming them then, in theory, there is nothing wrong with taking it.

As a scientist I do not condone the use of them as there is no evidence to show they actually work. But as a coach, if an athlete takes something that 1) is not on the banned list, 2) does not contain any harmful ingredients, and 3) does not cause adverse side effects, yet it makes them feel better----how can I tell them to stop taking it?

So it is a tricky crossroads between the lab and the field, but one we have to navigate often!

Kind Regards,