Cramping - the cause may not be what you think

We have all experienced cramping at some point in our athletic careers. Sometime it can be so bad that it simply stops you in your tracks, while other times it’s a simple annoyance. For the purpose of this short article, I will cover exercise induced cramping & its potential causes.

For decades the leading theory has been dehydration and a depletion of electrolytes and minerals as the culprit for the onset of cramping. However, in recent years the scientific studies are indicating something entirely different as origin of your mid-race crampfest…overuse, or fatigue, of a particular muscle that results in altered neuromuscular control. Simply put, the muscle loses its ability to relax. The condition can last from a few seconds to several minutes in duration. But one thing that can’t be denied is that it hurts.

This theory of altered neuromuscular control that results in exercise induced muscle cramping comes, in part, from a 2008 study that appeared in the British Journal of Sports Medicine in 2009. Martin Schwellnus UTC/MRC from the University of South Africa theorizes that the pathophysiological mechanism for muscular cramping during exercise is due, in part, by muscular fatigue that develops a cascade of resulting triggers. In short, the working muscle fatigues leading to an alteration in the neuromuscular control, which then leads to an increase in motor neuron activity, a resulting increase in muscle cell membrane activity and, finally, muscular cramping.

What is uncertain is how an imbalance of electrolyte concentration in the blood, in particular sodium, calcium, magnesium and potassium, along with dehydration plays into the equation. For years the compelling theory for exercise induced cramps was just this. But as further studies are conducted it appears unlikely that dehydration and electrolyte depletion, by themselves, is the culprit.

What about physical conditioning? The more fit an athlete the longer they can sustain a given effort to exhaustion. The onset of fatigue is thus delayed. This is something that I have recognized in my own training and have noticed in athletes that I have trained over the years. The more conditioned an individual becomes the less likely they are to experience exercise induced cramping. Please note that this is by no means a scientific study, but merely my professional observations over the past 14 plus years as an endurance coach. How does being physically fit for a given sport affect the body’s ability to keep from cramping? It is uncertain and more studies are in progress to determine how this aspect of physiology contributes to the cramping mechanism.

So what does all this mean to you, the age group athlete? For starters you should still pay close attention to your hydration and proper fueling, including electrolyte intake. The process of energy production in the body is driven by water and the various electrolytes. For this reason alone you should be concerned about keeping on top of this aspect of your training. Second, is to train, train & train. Aim to achieve the best possible fitness & sport specific strength over the course of the season. The stronger and more fit you are the longer you will be able to sustain a higher effort without the onset of fatigue and this can severely delay the mechanism that eventually results in cramping.

The bottom line is that we do not know for certain the exact cause of exercise induced muscular cramping. We are certain, however, that the pathophysiological triggers are far more complex than originally imagined. Sports scientists from around the world are utilizing the resources at their disposal to try and answer this decades old question. Until then, we’ll have to keep training and hope that we do not experience the pain from cramping anytime soon.