Muscle Cramps

Despite modern science, the true cause of exercise-induced cramps is not known.

It’s the racer’s worst nightmare: you’re running along and suddenly your calf seizes up or you’re crippled with a muscle cramp. It’s the most mystifying of running problems. The truth is that we still don’t know much about these debilitating muscle issues.

“Nobody knows what causes cramps,” said Dr. Gabe Mirkin.

There are, though, a number of theories.

For years, people believed that cramps were caused by salt and mineral deficiencies, dehydration, or heat. An increasingly large number of studies, though, have found there to be almost no connection between hydration or mineral intake and exercise-induced cramps. Studies have shown no difference in hydration or sodium make-up in muscle samples between runners who had cramps and those who didn’t.

“Although the idea that mineral deficiencies and dehydration can cause cramps has been very popular, we have done many, many studies that do not prove these as causes for cramps during exercise,” said Martin Schwellnus of the Department of Human Biology at the University of Cape Town, who conducted a number of these studies.

While salt loss and dehydration can certainly cause problems and generalized cramping throughout the body, it hasn’t been shown to cause specialized exercise-induced cramping, such as one would experience in a calf.

With the growing research on cramps, the current theory on what causes them is muscle fatigue and failures in the neural communication pathways. Basically, you train a muscle to contract and the muscle fatigues. It, then, miscommunicates and stays contracted when it shouldn’t, causing a cramp.

“The mechanism for muscle fatigue and muscle damage causing cramping is best explained through an imbalance that develops in the nervous system control of muscle. Muscles tend to become very twitchy when they become fatigued or are injured,” said Schwellnus. You’re more likely to get cramps, then, when your muscles are working harder and are fatiguing, such when you’re out of shape or racing hard.

Once a cramp strikes, you really only can do one thing: “Take a deep breath, stop, and stretch,” said Harnish. Static stretching has been shown to stop cramps, because it inhibits muscle contraction. Then, start slow and build your speed up.

“If you back off early enough, you can usually prevent it,” said Mirkin. Once a cramp comes on, it can be debilitating and impossible to continue, then “the only choice is to back off.”

Wouldn’t it be better to back off and stop the cramp early? After the race, it’s time to get to work. The more training you do at the speeds you plan to race at, then the better prepared you’ll be — though that’s true for more than just preventing cramps.

“The better shape you’re in, the less likely to get cramps,” said Mirkin.

It’s important to do training at the pace you plan to race, including progression runs and fast finish runs, said Harnish. You may get some cramps, but you’ll also get fitter and be more prepared to deal with those issues in a race. “I’d much rather cramp in training,” said Harnish.

The other thing you can do is to make sure you know what you’re really suffering from. Plenty of people who say they’re struggling with cramps actually have side stitches or stomach problems. Stomach cramps can simply be gastrointestinal issues, said Harnish, not really cramps. And, side stitches have “nothing to do” with cramps, said Mirkin. They may have similar roots, though. You’re more likely to get side stitches when you’re out of shape and overstretch your breathing and diaphragm muscles. They can be solved relatively simply, said Mirkin, by pushing on the stitch with your fingers and blowing out through pursed lips.

Actual exercise-induced muscle cramps, though, remain harder to understand. Despite what you might have been told as a kid, eating a banana probably won’t help. The only thing that will help is stretching, slowing down and training.

Prevention of muscle cramps

Muscle cramps hurt. After experiencing them, you will want to make sure they don’t happen again. Not knowing exactly what causes cramps makes it a challenge to prevent them. However, there are some things you can do to reduce their occurrence.

Train specifically for your race. If your race has a significant amount of uphill or downhill, replicate it in training so your legs and body can adjust to the workload.

Pace yourself. Going out too hard, especially harder than you trained for, will cause your body to fatigue early, putting you at a higher risk for muscle cramps. “When you are out of shape, and then engage in high intensity, prolonged exercise you would put yourself at risk for developing cramping,” said Schwellnus. Hydrate and stay on top of electrolytes. While the lack of fluids or electrolytes do not necessarily cause cramps, keeping them in check will help your body feel and function efficiently. •••