How – and why – endorphins are produced in the brain when you run, and what you can do to boost your chances of triggering a rush of the feel-good chemical.
Sometimes we get it, sometimes we don’t. But we always want it – and more of it. It’s the runner’s high, and when we’re lucky enough to tap into it, our runs feel easy, exhilarating, even euphoric. But we aren’t always that lucky, are we?
The reason for achieving the ‘runner’s high’ can be hard to pin down. But research, published in the journal Psychoneuroendocrinology, might just hold the answer.
Researchers studied how the brain responds to running and found that the ability to get ‘high’ while logging kilometres might be hard-wired within us. Years ago, our ancestors’ survival likely depended on chasing down food. The desire to live was possibly their motivation to run, and the feel-good brain chemicals released when they did so may have helped them achieve the speed and distances required, says David Raichlen, professor of biological sciences at the University of Southern California. The runner’s high may have served (and serves today) as a natural painkiller, masking tired legs and blistered feet, he says.
Even though we no longer need to chase down dinner, learning how happy brain reactions are sparked may help us achieve the runner’s high more often. Here’s what to know so you gain that other-level run.
The role of endorphins in the runner’s high
Nature’s home-brewed opiates, endorphins are chemicals that act a lot like their medically engineered counterpart, morphine. Runners have credited them for their feel-good effects for decades, but it wasn’t until 2008 that German researchers used brain scans on runners and were able to identify where they originated.
The study found that during two-hour-long runs, subjects’ prefrontal and limbic regions (which light up in response to emotions like love) spewed out endorphins. The greater the endorphin surge in these brain areas, the more euphoric the runners reported feeling.
How to boost endorphins
Push yourself hard, but not too hard.
Endorphins are painkillers produced in response to physical discomfort, says Matthew Hill, associate professor at the University of Calgary’s Hotchkiss Brain Institute in Canada. But that doesn’t mean your runs should be excruciating; you need to find a sweet spot where they’re comfortably challenging (think: tempo run).
In the German study, for example, the subjects were experienced runners for whom a two-hour run at a pace of 5:19 to 6:13min/kilometre pace wasn’t easy, nor was it gut-busting. ‘Most runners I’ve worked with experience endorphins when they’re pushing their bodies, but not usually at max effort,’ says Cindra Kamphoff, director of the Center for Sport and Performance Psychology at Minnesota State University. A short, casual run likely won’t produce enough discomfort to trigger a rush, but if you attempt a pace or distance that’s too aggressive, you’ll possibly be too overwhelmed by the effort to feel good. As powerful as they are, endorphins can’t override an injury or lack of training (which is why new runners aren’t likely to feel elated when they’re just starting out).
Hooking up with others could also help: an Oxford University study reported that rowers who exercised together significantly increased their endorphin release compared with solo rowers.
When you are on your own, consider wearing headphones: research shows that listening to your favourite music may spike endorphins.
The role of endocannabinoids in the runner’s high
Endorphins get all the attention, but your body also pumps out substances called endocannabinoids, which are a naturally synthesised version of THC, the chemical responsible for the buzz that marijuana produces. The most examined endocannabinoid produced in the body, anandamide, is believed to create a feeling of calmness, Dr Hill says. Endorphins can be created only by specialised neurons, but pretty much any cell in the body is capable of making endocannabinoids, which means they have the potential to make a bigger impact on your brain.
How to increase endocannabinoid levels
Endocannabinoid production is believed to react more strongly in response to stress, rather than pain (the stronger endorphin activator). Differentiating between physical stress and discomfort during a run is nearly impossible, which means the same mechanism that triggers endorphins can also trigger endocannabinoids: a challenging (but not killer) workout.
Professor Raichlen says that running at 70% to 85% of your age-adjusted max heart rate (you can approximate yours with this equation: 211 – (0.64 x your age) is optimal for spiking the stress hormone cortisol and producing endocannabinoids. (If you’re 30, you’d aim for 134 to 163 beats per minute.)
Dr Hill’s research suggests that, in small doses, mental stress may also increase endocannabinoid production, so pre-race jitters could have a pay-off. But chronic stress can dull this effect.
That may be one reason why Cecilia Hillard, director of the Neuroscience Research Center at the Medical College of Wisconsin, has found that people need eight hours of sleep a night for optimal endocannabinoid production. What’s more, her research demonstrates that endocannabinoid levels are three times greater first thing in the morning compared with when you hit the hay. Though there’s not yet any concrete scientific proof, this could suggest that a morning run is more likely to produce a high than an afternoon or evening run. So set your alarm; it’s worth experimenting.
We mentioned before that running with a partner may help you out. But just because your running buddy gets that coveted runner’s high doesn’t necessarily mean you will. Or at least, you may have to keep tinkering.
Research demonstrates that endocannabinoid levels are three times greater first thing in the morning
In 2019, a study looked at 25 college runners and tested their saliva before and after a long-distance run. (They focused on saliva because it contains information on RNA, which is what your DNA uses to make feel-good proteins, like natural opioids and cannabinoids.) But not everyone’s processes hit at the same degree, which means that you might have a runner’s high while your running partners are still in slog mode.
The study’s lead author, Steven Hicks, associate professor in the paediatrics department at PennState University College of Medicine, suggests playing around with different conditions – like longer runs or more sprinting, for example – to turn the proper pathways on.
‘Whether endorphin or endocannabinoid, it’s helpful to find a few different ways to stimulate the high to keep your body from getting too accustomed to a routine [which might result in either a decreased release or a down-regulation of the related receptors in the brain],’ Vasudevan adds. ‘This is not unlike when people use exogenous opiates and cannabis. So, the more we vary our routines, while still putting in the appropriate intensity, the more often we can maintain the positive experience overtime.’
5 steps to a runner’s high
Experiencing a runner’s high is not like turning on a switch but, as we’ve learned from the research, doing the following can increase your chances:
1. Do tempo runs
Working out at 80% to 90% of your maximum heart rate is optimal. Think the ‘comfortably hard’ level of a tempo run.
2. Run longer
An easier run duration of one to two hours is the sweet spot for producing highs.
3. Get more sleep
Eight hours of sleep a night is optimal for endocannabinoid production.
4. Work out with others
Research on rowers showed that those who exercised together significantly increased their endorphin release when compared with solo athletes.
5. Listen to music
Hit pause on the podcasts and run to your favourite running playlist for an endorphin kick.