What are muscle cramps and what can you do about them?

Do you suffer from exercise-induced cramps? If you’re physically active, there’s a chance you may have suffered a muscle cramp and wondered what caused it.

 A muscle cramp is a sudden, involuntary contraction of one or more skeletal muscles. It can cause pain and discomfort and make it difficult to move the affected muscle. Muscle cramps can strike during or after exercise and may be relatively minor or cause pain which can linger for days.

Why do cramps happen? Why would a healthy muscle ‘lock up’?

The honest answer is that scientists don’t know for sure. Even after years of research the cause of these unpredictable spasms is difficult to identify, however there are two main theories:

• an upset to your body’s water and electrolyte balance

• your nervous system is sending messages to a muscle, telling it to contract abnormally because of nerve and muscle (neuromuscular) fatigue.

These may each play a role, but it seems likely that cramping is due to various factors, not a single cause.

What you can do about cramps

While we can’t be certain about the ‘why’, we can share what might help. The first you probably know; that stretching or lengthening the affected muscle may help. For example, your calf − the most common site of cramping − can be stretched by keeping your leg straight and pulling your foot and toes towards your knee.

There’s a higher risk of your muscles cramping when you sweat a lot, so keeping hydrated is essential. You may find that taking electrolytes helps. There isn’t much journal evidence to support this practice, but if it works for you, it’s worth doing. You can read about electrolytes in this month’s companion article. Training to improve fitness and strengthen the susceptible muscles may also help.

Luckily, exercise-induced cramps aren’t usually related to anything nasty and tend to settle quickly. If you have any questions we’re here to help.