Motivation

Is Runner's High Our Evolutionary Antidote for Staying Put?

There is a strong link between runner's high and the motivation to exercise.

Posted October 7, 2015

Source: Pixabay/Free Image

Researchers have discovered that activating specific opioid receptors in the brain can trigger the runner’s high without exercise. These findings offer new clues on how experiencing runner's high motivates both animals and humans to voluntarily seek exercise. "Runner's high" is often described as a feeling of euphoria after exercising—it is a combination of decreased anxiety, positive emotions, and a higher tolerance for pain.

Turning Off Specific Opioid Receptors Reduces Runner's High

An October 2015 study, "Mu Opioid Receptor Modulation in the Nucleus Accumbens Lowers Voluntary Wheel Running in Rats Bred for High Running Motivation," was published in the journal Neuropharmacology. Although this study breaks new ground, the exact role that mu-opioid receptors play in motivating voluntary running by creating runner's high remains mysterious.

To provide a better understanding of how reward pathways and pleasure centers associated with runner's high motivate lab rats to run on a wheel, a team of scientists at University of Missouri bred one group of rats to be highly motivated to run voluntarily, and another group to have an aversion to running. Basically, one group of rats was born to run; the other group was born to be couch potatoes.

The researchers gave chemicals to the rats that would either activate or shut off their mu-opioid receptors. These receptors are associated with runner's high in the brains of both rats and humans. Interestingly, when the rats who had been bred to love running got a runner’s high from the chemicals, they lost interest in exercising.

In a press release, Greg Ruegsegger, lead author of the study said, "These highly active rats would run on their wheels constantly. However, when we chemically activated their mu-opioid receptors, those rats drastically reduced their amounts of activity.” The researchers also found that activating or shutting off the mu-opioid receptors in the lazy rats didn't alter their predisposed activity levels.

When the researchers examined the brains of all the rats postmortem, they found 400 percent more reward receptors in the extremely active rats than in the extremely lazy rats. This indicates that the extremely active rats were able to experience the rewards of runner's high because of their mu-opioid receptors, which may explain why they voluntarily ran so much. The same could be true in humans.

Runner's High Is Linked to Endocannabinoids (Your Body's Own Cannabis)

Another recent study, conducted by researchers at the University of Hamburg and the University of Heidelberg, examined cannabinoid receptors in mice after running. The scientists confirmed that runner’s high is strongly associated with cannabinoid receptors in the brain.

The October 2015 study, "A Runner’s High Depends on Cannabinoid Receptors in Mice," was published in Proceedings of the National Academy of Sciences.

For decades, the general consensus has been that runner’s high is caused by increased levels of beta-endorphins (your body's own morphine). However, the German researchers identified that these endorphins are too big to get through the blood-brain barrier. They believe endocannabinoids are probably more central to the runner's high phenomenon.

Sweat and the Biology of Bliss

The findings from both of these studies make sense to me as an ultra-endurance athlete, "human lab rat," and science writer. I've been researching and road testing this topic for decades.

In The Athlete’s Way: Sweat and the Biology of Bliss (St. Martin's Press), I describe my neurobiological relationship to runner’s high and the foundation of my platform. Although, I wrote the passages below over a decade ago, the recent findings on runner's high reaffirm the fundamental philosophy of The Athlete's Way. In my Note from the Author on the first page of the book, I said:

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"When I am running, biking or swimming happiness pours out of me. I am not alone. Everyone who exercises regularly experiences this bliss. And it is available to you, too, anytime you break a sweat. The Athlete’s Way is an individual process but ultimately a universal experience.

Everything that human beings do for our survival—eating, sleeping, reproducing, and working physically—breaking a sweat—is designed to make us feel good biologically. We are rewarded for doing the things necessary to stay alive. This is a generous biological design, and at the same time, the key to our survival.

All animals seek pleasure and avoid pain. Maintaining life in the human body was designed to be an ecstatic experience, as was bonding with other humans. Throughout our evolution, physical exertion and sticking together have produced neurochemicals that scientists are just beginning to identify as being associated with happiness.

One reason the psycho-pharmacological business is booming is that our bodies are not designed to be sedentary or isolated behind computer screens. Doctors prescribe pills to make people feel better—I prescribe sweat, community, energy balance, and a sense of purpose.

Humans need to move. Organic, self-produced bliss, kinship, and stress reduction are available to all of us, if we are willing to break a sweat, bond with other human beings, and chase our happiness down."

In my first book, I also identifed endocannabinoids, not endorphins, as the prime driving force behind runner's high. This insight, from over a decade ago, was based on conversations with my father, Richard M. Bergland, who was a neuroscientist, neurosurgeon, and author of The Fabric of Mind (Viking).

If you'd like to read free excerpts about the connection between endocannabinoids and runner's high from The Athlete's Way click here. On pp. 105-107, I said,

"One of the groundbreaking revelations this book brings to the mainstream is that endorphin is not the prime cause of runner's high. As with every process in the body, the reaction results from a myriad of chemicals, but the spotlight of neuroscience is pointing toward the endocannabinoid system, and in particular, anandamide, the "bliss molecule."

Endocannabinoids are the most potent neurochemicals for creating the biology of bliss when you exercise. Endocannabinoids are not a household word yet, but I guarantee that by the end of the decade they will be as commonly known as serotonin, dopamine, and cortisol.

Cannabinoids are directly linked to feelings of pleasure and have analgesic and anti-inflammatory properties. Cannabinoids are released when you break a sweat, they linger in your system during and after the process. They are linked to neurogenesis, improved mood, bone density, and fine motor-contol improvement in endogenous doses. The receptors in the brain for cannabinoids are called CB-1 and they are everywhere, but are especially dense in the frontal lobes and cerebellum."

It's fun to go back and read the above passages. So many of my dad's hypotheses about the brain have been confirmed by 21st century scientific research. As a neuroscientist in the late 20th century, my father grew frustrated by technological constraints that made it impossible for him to prove many of his theories in a laboratory. Most of my father's ideas about the brain were revolutionary and ahead of their time. If he were alive today, I'm sure he'd be thrilled to read about the latest findings on runner’s high from these two studies released this month.

Conclusion: Do You Experience Runner’s High When You Exercise?

Source: Subbotina Anna/Shutterstock

Although both of these studies were conducted on rodents, some humans are probably born with more mu-opioid and CB-1 receptors, and some people are probably born with fewer of these reward receptors. Although everybody can experience some degree of a runner's high, for some people it may be more subtle than it is for others.

Some of us definitely experience a very intense runner’s high when we exercise. This is both a blessing and a curse. Most endurance athletes, like myself, seem to develop an excessive drive to activate these reward centers through exercise, which has the potential to throw their lives out of balance.

My passion for becoming an ultramarathoner and to run insane distances was never a reflection of “willpower” or “discipline." In my case, ultrarunning started out as a pursuit of "otherworldly" peak experiences, but eventually it became like a drug that consumed my life. As an ultra-endurance athlete, I put my daily runner's high before everything else in my life, including friends and family. My life was completely out of balance. These days, I strive for a consistent “tonic level” of physical activity most days of the week, which makes me feel good, but does not consume my life.

On the other end of the spectrum, many people I have spoken with over the years tell me that they’ve never experienced a runner’s high. I think this could be due to fewer mu-opioid and CB-1 receptors, but it could also have to do with perceptions of what runner's high actually feels like. In many ways, the runner's high is primarily a relaxation response caused by a reduction of stress hormones through exercise that doesn't necessarily feel euphoric.

Regardless of the extent that someone experiences the ecstasy, or calming effects, of runner's high, it's important to remember that the positive emotions and stress reduction associated with physical activity are universal and available to us all.

If you'd like to read more on this topic, check out my Psychology Today blog posts,

Follow me on Twitter @ckbergland for updates on The Athlete’s Way blog posts.

The Athlete’s Way ® is a registered trademark of Christopher Bergland