New Thinking on Muscle Cramps

Rafa Nadal with muscle cramp

An article published this month in the active lifestyle magazine, Outside outlined the latest thinking on muscle cramps by a Nobel Prize–winning neuroscientist, Rod MacKinnon and a Harvard neurobiologist, Bruce Bean. Below are the key points from the feature…

‘From tennis star Rafael Nadal (2011 U.S. Open) to marathoner Dathan Ritzenhein (2012 Olympic trials), athletes the world over have been plagued by painful muscle spasms that show up in the crucial late stages of fierce competition. Inevitably, these cramps are blamed on heat and dehydration. Research tells us that neither have anything to do with it.’

‘For much of the 20th century, physiologists believed that athletes cramped because they became dehydrated or lost electrolytes through sweating. But that hypothesis fell out of favour in the late 1990s, when a South African doctor named Martin Schwellnus theorized that distorted neural signaling between an athlete’s muscles and the spine was the true culprit. When you’re fatigued, he proposed, the motor reflex responsible for sending a “relax” signal to the spine becomes tired. When this happens, the “contract” signal keeps firing, and muscles become stuck. With no definitive research on how to combat the faulty signal, athletes were left with two options: don’t push too hard, or stop to stretch when cramps happen.’

Female athlete with muscle cramping

‘As they pored over the existing research, Bean and MacKinnon zeroed in on one thing: even though cramps didn’t have any relation to electrolyte balances, some studies showed that drinking pickle juice or eating mustard helped prevent them. The pair knew that pickle juice and mustard contain molecules called ion-channel activators, which trigger nerves in the digestive system. These activators are why spicy foods feel hot: they don’t burn you, but they trigger the same nerve response that occurs when you come into contact with heat. Bean and MacKinnon wondered whether the activators in pickle juice and mustard were simultaneously calming nerves in other parts of the body that are responsible for muscle contraction. “We thought, If this is correct, there are much more potent activators,” MacKinnon says.’

‘The pair had also come across research showing how to induce cramps in the lab by electrically stimulating muscles. They began experimenting with a home-brewed drink packed with several kinds of ion activators, taking sips and trying to zap their feet into cramps. The early results were so encouraging that they filed a patent for their [drink supplement.]’

‘MacKinnon says that they’ve tested the supplement in randomized, controlled studies and found that it reliably raised the threshold at which athletes cramp.’

footballer with muscle cramp

‘Jeffrey Edwards, an exercise physiologist at Central Michigan University who studies cramps is intrigued by [Bean and MacKinnon’s findings.] “We have all kinds of evidence that one set of receptors over here can affect nerve functions somewhere else,” he says.’

‘MacKinnon says that [the supplement] helps prevent cramps for approximately five hours. Just don’t expect it to taste like your favourite energy gel. “It’s a mix of hot and pungent,” MacKinnon says. “That’s what makes it work.”’

‘MacKinnon and Bean are also pursuing FDA approval for a drug that would treat cramps associated with multiple sclerosis and ALS [amyotrophic lateral sclerosis (ALS), also known as Lou Gehrig’s disease].’

The article can be read in full here.


1 thought on “New Thinking on Muscle Cramps

  1. avoiding to push too hard is a better option. Overworking our muscles can definitely cause them to go haywire. One should always be vigilant not to overuse them.

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