How muscle memory can help you back to running after injury

Illustration by Rami Niemi

Many runners have been there – lacing up for the first time after a break from training and praying there is such a thing as muscle memory. For example, 48-year-old Jeff Alexander ran his first marathon in 1996, finishing in 3:03. He ran his second the following year in 3:07, and his third the year after that in 3:06. He was dangerously close to hypothermia in that final race, and that experience, coupled with major life changes, including a move and a marriage, caused Alexander to fall out of his training routine. And although he attempted to keep up with regular short runs, ‘beer often got in the way’, he says.

But 10 years later, Alexander returned to distance running. He qualified for Boston with a time of 3:17 – and with less difficulty than he had expected. ‘Heading out, it felt familiar,’ he says. ‘I was up to 10 miles within the first month. I’d say the muscle memory was intact.’

Play it safe

Experts say Alexander isn’t wrong to think his previous training put him at an advantage, although the term ‘muscle memory’ can be misleading. ‘A muscle doesn’t have its own brain, so it can’t literally remember things,’ says Steven Devor, assistant professor of kinesiology at Ohio State University, US, and a runner.

And just because you might be able to ramp up your training faster the second time around doesn’t mean you should. Doing too much too soon could leave you hurt – especially if your original layoff was caused by injury. In that case, it’s a good idea to visit a running clinic or to see a medical expert for a gait evaluation, before you resume running. ‘If your last run [before injury] was dysfunctional, you risk slipping back into those poor habits,’ says Amadeus Mason, of USA Track & Field’s sports medicine and science committee. So while your muscles don’t actually remember, you won’t be starting from scratch when you return to running. But how?

READ: What are the rules for a first run after an injury lay-off?

Why it sticks

It’s very likely that at some point in your life you’ll need time off from running. You’ll become a parent, get sick or injured, or even take a midlife-crisis sabbatical to learn how to skydive. But rest easy: every time you run, you ‘bank’ muscle memory. Those deposits become a type of running nest egg you can cash in down the road. ‘The more times you go over the memory now, the longer it will last,’ says Mason.

And there is certainly a major psychological factor: revisiting a sport, especially one you once enjoyed, is far less intimidating than taking it up for the first time. And confidence can make re-entry to your sport feel easier.

But experts say it’s more than that. To begin with, when you strengthen your muscles, they generate more nuclei, or ‘little protein factories’, that contain DNA necessary for increasing muscle volume, says Kristian Gundersen, professor of physiology  at the University of Oslo, Norway. A study led by Gundersen in 2010 confirmed that even after you give up exercising, these nuclei stick around, meaning former runners are one step ahead when they decide to get back into the sport.

‘When you do an activity, the brain sends messages to your muscles in the form of electrical charges through pathways in the central nervous system, and the muscles send messages back,’ says Matt Silvis, a sports medicine physician at Penn State Milton S. Hershey Medical Center, US. Because of this constant feedback loop the right muscles are activated to perform a particular task. Do this task often enough and these pathways become well trodden, which is why you never forget how to ride a bike – or how to run.

READ: Muscle memory and endurance

You're a natural

You don’t just remember how to run – but how to run well. ‘Even after a long break, you’re going to run more efficiently than someone who’s new to the sport,’ says Adam Knight, assistant professor of biomechanics at Mississippi State University, US. ‘You can make the assumption you’ll get back in shape more quickly because of that.’

Perhaps the best news for runners is that these pathways don’t apply just to voluntary muscles, such as those in the legs, but to involuntary muscles, such as the heart. ‘For former athletes, there is a lot of residual benefit to exercise within the circulatory system,’ says Alfred Bove, professor emeritus of medicine at Temple University, US, and past president of the American College of Cardiology. ‘In well-trained athletes, the heart is able to relax more easily, which minimises shortness-of-breath issues. Also, the parasympathetic nervous system [which slows down your heart rate] becomes more dominant than the sympathetic nervous system [which speeds it up], meaning the heart is less stressed by exercise. Both of these adaptations have memory.’

READ: Rules of running for returning from injury or pregnancy

Total recall

There are things you can do beyond just running to help entrench the habit in your muscle memory.

1/ Visualise

This positive-thinking tool stimulates the same pathways through the central nervous system that are active during actual running.

2/ Eat

Upping your intake of antioxidant-rich spinach, blueberries and strawberries can help protect your ability to produce muscle memory as you age.

3/ Sleep

A 2013 study suggests that an athlete who experiences ‘slow-wave’ sleep, or deep sleep, is better able to produce muscle memory.

4/ Strength-train

It helps muscles generate more nuclei that contain the DNA necessary for increasing your muscle volume.