Christine, one of our Sunday morning regulars, asked this morning, “How do I get rid of muscle cramps?”  Sounds simple, and surely there is a scientific explanation and answer, right?

No one knows.

That’s the answer.  At least, no one who has done the research and looked for a cause, and has evidence to support their conclusions has an answer.  In an excellent article by Kevin Miller, Marcus Stone, Kellie Huxel, and Jeffrey Edwards, sports physiology scientists, titled “Exercise-Associated Muscle Cramps,” (Sports Health. 2010 Jul; 2(4): 279–283), and provided through the National Institutes of Health, the subject of muscle cramps in athletes is reviewed in depth.

There are myriad theories and cures for this vexing problem.  Most of the theories and suggested cures are based on hunches, anecdotes and guesses.  The most common thoughts about why muscle cramps occur in athletes have to do with dehydration and loss of electrolytes.  The thinking goes that if one is dehydrated, meaning a loss of free water in the body, and loss of electrolytes such as sodium, potassium and magnesium, the nerve terminals to muscles are over-sensitized leading to cramps.

Another leading theory is based on neuromuscular interactions.  This theory states that, in overworked muscles, excitatory impulses and inhibitory impulses are not in balance, and the excitation of muscle fibers wins out.

The report mentioned above goes into detail about these theories, looks at the research that has been done in these areas, and the reasons that these theories are not clearly supported by the research.

Most muscle cramps in athletes occur well into a workout or race, or occur after the end of the event.  There is a period during which muscle cramps occur after the event is finished called the “cramp prone state”, and until this period is finished, which may be eight hours or longer, the athlete is still susceptible.  While some cramps may be minor, and not interfere with performance, often the cramps can be debilitating.  Many cures have been tried over and over, with only anecdotal evidence to back them up.  Sports drinks containing (minimal) electrolytes, pickle juice, mustard, bananas, oranges, cold therapy, hot therapy, massage and TENS (trans-cutaneous nerve stimulation) have all been used.  But studies looking at hydration status, electrolyte status and all the above mentioned cures have failed to show statistical improvement in study groups.  Known to work to relieve a cramp, but not for prevention, stretching will stop the cramp.  However, that is a temporary solution, and not one that will prevent a cramp the moment activity is resumed.

I have been plagued with cramps, mostly of the legs and thighs, throughout my athletic career, starting from when I swam as an eight year old.  In my experience, the cramps are less likely to occur the better condition I am in.  When I was a competitive swimmer, the early part of the season was the worst, but as my training went on, they were less and less a problem.  Now, as a runner, and mostly with long distances, I find the muscle cramps hit me very consistently during a marathon, usually around the sixteen to eighteen mile mark.  This is in spite of maintaining good hydration, using salt or drinking electrolyte drinks, and supports the contention that these factors don’t play a role.  My best marathon performance, in which cramps definitely played a very minor roll, was the one where I had trained the best and most consistently.  There are plenty of good reasons to stay well hydrated of course, which have to do with other body systems.  Running in the heat and humidity causes excessive fluid losses, raises core body temperature as the body has trouble getting rid of excess heat, and can lead to hyperthermia and affect kidney function.  Overhydration by consuming too much water to replace losses, can cause hyponatremia, meaning too low sodium levels, which is equally serious.

Kevin Miller, the lead author of the article mentioned above, wrote a simplified version of myths regarding muscle cramps and what to do about them, called “Exercise-Associated Muscle Cramps: Debunking Five Myths”.

While research into the reason for muscle cramps and the treatment has not provided an answer, he makes sound suggestions on how best to avoid them.  If you wish to have a more complete understanding of the research and conclusions, his paper is a good source, and provides many references on which it is based.  I hope your runs are as cramp free as possible.  Happy running.