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The reason you’re cramping while running

A look at the cause of your mid-workout discomfort

A cramp is one of the most frustrating running injuries. While usually short lived, a mid-run cramp can quickly derail a workout or make a run significantly less enjoyable. Everyone’s experienced them, but it’s hard to identify what brings them on and exactly how to get rid of them. Lauren Roberts is the owner and a physiotherapist at The Running Physio clinic in Toronto who says the research is very divided on the topic and that the reason for cramping remains elusive.


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The reason you’re cramping

“The actual mechanism for cramping is still pretty unknown,” Roberts says. “For a long time, people thought it was a nutrition thing, but there’s a lot of research that has since debunked that theory. The latest train of thought is largely that cramping comes from a neuromuscular cause, meaning it’s most likely going to occur in a circumstance when you’re running so much harder than you’ve trained for.”

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She continues, “These cramps tend to come when people have overshot their pace or when they’re going harder than they prepared for. The nerve that sends messages to the muscles short circuits, so to speak. The message from the brain to the muscles becomes confused, and results in recruiting too much muscle, and having it subsequently cramp up.”

Roberts feels that ultimately, cramping is most likely to happen when you’re going too hard, too fast. “It’s really hard to mimic the true fatigue of a race scenario, which is why cramps happen so often on race day. But the exact cause remains quite elusive– there’s no hard and fast reason quite yet.”

Should you stretch it out mid-run?

Stretching mid-run may help, but Roberts explains that it’s not the actual stretch that’s fixing the problem. “You are giving your neuromuscular patterns a chance to reset. Stretching may help it, but what’s more likely to happen, even with stretching, is a resurface.”

If a cramp is nagging you mid-run and a stop to stretch hasn’t fixed anything, it’s time to call it a day. “The most important piece of information you can take away is that what you’re doing was a little too hard, so scale your pace back. Chances are you’re tending toward an injury-risk level if you’re pushing this hard anyway.”

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