The relationship between stress and running is complicated, says Sam

Being a runner can put you in stressful situations. Donning your trainers to head out in public for the first time can have your heart racing and your palms sweating before you’ve even taken a step. Finding yourself pursued by a barking dog can turn a Sunday jaunt into momentary terror. Battling to the finish line, neck and neck with an opponent, can send the stress dial spinning into the red zone. The act of running places ‘stress’ on the body – triggering physiological responses, including the release of hormones associated with stress, such as cortisol and adrenaline. But just as regular running triggers adaptations to your fitness level, so does it temper the stress response. And that goes for not just your stress response to running, but to life in general.

A 2005 study1 measured levels of cortisol in fit, active women versus untrained, inactive women when they were faced with a socially and psychologically stressful situation, and found they were significantly higher in the latter group.

In another study, researchers measured ‘negative affect reactivity’, which refers to how someone perceives their experience of unpleasant stressful events. They found exercisers’ negative affect was 14 per cent lower than that of nonexercisers. It wasn’t that fitter people didn’t notice the stressful events; they just weren’t floored by them in the same way, and when asked to recall the stressful situation later on, they didn’t remember it as negatively as non-exercisers did.

In such a bumper year for stress, this is good to know. But it does not mean running can or should inoculate us against the effects of stress. Believing so can be a dangerous game. Why? Well, let’s say you’ve been running as much as ever, but it’s just not taking the edge off in the way it usually does. So you step up your training. The next thing you know, you’ve got an injury and you can’t run at all.

In a study by Wake Forest University, North Carolina, US, researchers observed 300 runners over two years to see what factors predicted who would get injured. There were some physical factors, but poorer mental health-related quality of life and negative mood states, including being irritable, jittery and nervous, were significant predictors of injury. In other words, running when you are stressed may increase your risk of injury.

‘We tend to put physical and mental things into two separate boxes,’ says Alex Hutchinson, author of Endure: Mind, Body and the Curiously Elastic Limits of Human Performance. ‘“My knee hurts because these shoes are worn out.” “I’m feeling sad and lethargic because I’m mostly running alone these days.” But that’s a little too simplistic. What’s going on in your mind affects how your body feels and vice versa.’

It’s still not clear what the link is between stress and injury. It could be that stressed runners push themselves harder, in search of that soul-soothing nirvana. Or it could be that, when stressed, we are distracted and fail to pay attention to the early warning signs of injury. Either way, we’d do well to remember that if our stress levels exceed our current runningbestowed capacity to cope, increasing mileage or intensity may backfire.

That’s not to say you should abandon running in the face of high levels of stress. But it might mean you need to find other avenues for relieving stress alongside running. It might mean you need to switch your focus – maybe giving races, virtual or real – a miss and leaving your watch at home for a while. Running with others can be helpful. A 2017 study found that working out in a group reduced stress by 26 per cent; working out alone showed no such stress reduction.

Hutchinson admits his running performance has taken a nosedive during the pandemic. ‘I’m pretty sure it has more to do with what’s going on in my head than what’s happening in my muscles,’ he says. Just knowing that one affects the other is reason enough to cut yourself some slack.