Somewhere towards the end of a long run, between the syncopated thrum of kicking legs and a sweaty brow, endurance runners can happen across a curious feeling of bliss. A mysterious sensation that suppresses pain, focuses the mind and, some say, transcends them into a trance like state or flow. “It’s like going from full vision to tunnel vision. Everything else just shrinks and all you’re seeing is what’s going forward” recalls five time Ironman Champion and On athlete, Matt Hanson. In extreme cases, the runner’s high can change even how a runner perceives the world, as has happened to Hanson, “I’ve ran past my wife so many times in a race, and not really known it.” This altered state of being is known as the runner’s high.
It was previously thought that the runner’s high was the result of endorphins, which inhibit the communication of pain signals, but recent findings suggest otherwise. Closer examination of aerobic activity has provided some curious new concepts about this altered state of being, deriving from the same system that interacts with tetrahydrocannabinol, or THC, the psychoactive ingredient found in cannabis. So is running actually getting us high? Not quite. Some hypothesize that this sensation is actually a neurobiological reward that motivates human endurance exercise.
The runner’s high is now being attributed to the endocannabinoid system, not endorphins. This system is made up of neurotransmitters, which regulates psychological and cognitive processes in the body and brain. It affects mood, memory and mitigates pain. Essentially, this system manages many operational aspects of the body during aerobic activity, like running, swimming or cycling. So while endorphins are still present during extended aerobic activity, one study from 2015 has provoked new considerations about why we experience the runner’s high at all. Reasons that point to our human evolutionary past.
“In order to be a carnivore, you have to be able to run. And instead of being great sprinters, which you can’t really do with two legs, we became great endurance runners.” So says author and Harvard Professor Daniel Lieberman. He believes that the endocannabinoid system, which produces natural opioids in the body to mitigate pain, allowed us to adapt over time to hunt prey, using a method known as persistence hunting. “That enabled our ancestors to hunt before the invention of weapons like the bow and arrow.” While these adaptations allowed us to change our diet, to better understand what’s happening in the body, let’s also consider what’s happening in the brain.
“The endocannabinoids are increasing sensory awareness,” says Professor Lieberman. “What’s the hunter doing while running long distances? The hunter’s tracking it. The hunter is chasing the animal. The hunter has to put themselves in the mind of the animal and see footprints and other traces, and see what’s going on in the environment. And what endocannabinoids do in addition to making you feel good about your run… the endocannabinoids also heighten your sense of sensory awareness.”
Altering one’s state of mind during a run may translate to more than just hyperawareness, it also leads to physical sensations in the body. “It can have these pretty interesting consequences in terms of how you perceive the discomfort and the pain, and how you’re able to take in your surroundings” says On athlete and middle distance runner Sage Hurta, describing how her mental state changes in accordance with her physical state as the runner’s high comes on. She goes on “It just can kind of alter your perceptions of what would normally just be another run. If your mind is this ocean, everything is very peaceful, and thoughts kind of come in and come out.”
This notion of serenity and focus is also echoed by Professor Lieberman, who hypothesized that the runner’s high is actually an adaptation, starting about 2 million years ago, when humans first began to walk upright, which then led to running, and eventually, running longer and longer distances.
While we may not have to hunt our food as we once did, we do stand to reap the rewards of our ancestors. It’s estimated from 2008 to 2018, marathon participation grew almost 50%. Even without persistence hunting, running long distances has become a part of daily life for millions of people. While humans have taken some pretty long strides from our ancient past to our present, there are still plenty of reasons to run. Whether it’s about engaging in a healthier, more active lifestyle, or simply searching for a transcendental flow on a nature trail, running is beneficial for both body and mind. The runner’s high isn’t just for athletes either, as triathlete Matt Hanson notes, “If everybody can feel that once in their life, they’re a lucky individual.”