What causes muscle cramps?

Adam’s Journal

If it can happen to LeBron James, it can happen to any of us.

Midway through the final quarter of game four of the NBA Finals last week, leg cramps felled the Miami Heat star. As a Thunder fan, I admit I experienced a surge of hope for our team. Still, I couldn’t help but feel sympathy for King James when he left the court carried by a trainer and a teammate, unable even to walk a few yards to the bench. The common cramp, bane of joggers and weekend warriors the world around, had claimed another victim. Only this victim was one of the world’s greatest and best-conditioned athletes.

So what causes muscle cramps? And what ‘s the best way to avoid them?


Dr. Prescott Prescribes

This can join “Chicken or the egg” and “How many licks does it take to get to the center of a Tootsie Pop” as one of life’s great unanswered questions. Because, as common as they are—79 percent of triathletes, 60 percent of cyclists and 39 percent of marathoners report having endured them at one time or another—no one really has a convincing biological explanation of what causes cramps.

There are three leading hypotheses out there. The first is that dehydration causes cramps. Others have posited that the muscle contractions are due to an electrolyte imbalance. And a third camp believes that cramps result from a different kind of imbalance, one between the nerve signals that excite a muscle and those that inhibit its contractions.

The problems with these hypotheses is that they are, for the most part, just hypotheses. Because it seems that few researchers have devoted the time or effort to figuring out how, exactly, cramps come about—and how best to treat them. Consequently, as was the case on the Heat sideline last week, you’ll see trainers treat cramps with everything but the kitchen sink: lots of fluids, electrolytes (either sports drinks or pills to restore sodium and potassium) and vigorous stretching.

In studies where researchers used electrical stimuli to try to induce cramp-like conditions in athletes’ big toes (the experiments would’ve been too painful if they’d used a larger muscle like the calf or quadriceps), they found that they were no more likely to induce the cramps in dehydrated athletes than in hydrated ones. But another study by the same group offers an intriguing, if not particularly appetizing, theory for treating cramps.

For that research, scientists once again tried to induce big-toe cramps through electric stimuli. When they succeeded, they had the subjects drink either 2.5 ounces of water or pickle juice, strained from a jar of Vlasic dills. Those who drank pickle juice recovered in an average of 85 seconds, markedly faster than those who drank water.

Although these results might seem to support the electrolyte hypothesis, the recovery time was too short for the salty juice to have left the athletes’ stomach and replenish electrolyte stores. So the best guess we have is that the acidic pickle juice may send out a nerve signal that counteracts a misfiring nerve signal brought on by exhaustion.

With no long-term damage associated with cramping (see, for example, LeBron’s performance in game five), don’t expect extensive research in this area any time soon. In the meantime, trainers could do worse than to keep a jar of pickle juice on the sideline just in case.