The Joy of Movement: How Exercise Helps Us Find Happiness, Hope, Connection, and Courage

by Kelly McGonigal

People who are regularly active have a stronger sense of purpose, and they experience more gratitude, love, and hope. They feel more connected to their communities, and are less likely to suffer from loneliness or become depressed.

The psychological effects of movement cannot be reduced to an endorphin rush. Physical activity influences many other brain chemicals, including those that give you energy, alleviate worry, and help you bond with others. It reduces inflammation in the brain, which over time can protect against depression, anxiety, and loneliness. Regular exercise also remodels the physical structure of your brain to make you more receptive to joy and social connection.

During physical activity, muscles secrete hormones into your bloodstream that make your brain more resilient to stress. Scientists call them “hope molecules.”

But for most of human existence, the central purpose of movement was not to prevent disease. Physical activity was how we engaged with life.

Human beings are hardwired to take pleasure in the activities, experiences, and mental states that help us survive. This goes beyond the obvious practical matters, such as eating and sleeping, to include many of the psychological traits that define us as humans. We enjoy cooperating and find teamwork fulfilling. We delight in making progress and take pride in what we contribute. We form attachments to people, places, and communities, and we experience a warm glow when we care for them. Even our ability to find meaning in life is rooted in the neurobiology of pleasure: stories and metaphors captivate the brain’s reward system, encouraging us to craft narratives that help us make sense of our lives.

Our ability to experience exercise-induced euphoria is linked to our earliest ancestors’ lives as hunters, scavengers, and foragers. As biologist Dennis Bramble and paleoanthropologist Daniel Lieberman write, “Today, endurance running is primarily a form of exercise and recreation, but its roots may be as ancient as the origin of the human genus.” The neurochemical state that makes running gratifying may have originally served as a reward to keep early humans hunting and gathering. What we call the runner’s high may even have encouraged our ancestors to cooperate and share the spoils of a hunt.

As part of Pontzer’s research project, his team gave nineteen Hadza men and twenty-seven Hadza women activity trackers and heart rate monitors, then recorded their dawn-to-dusk activity. On a typical day, the Hadza engage in two hours of moderate to vigorous activity, like running, and several more hours of light activity, like walking. There is no difference in activity level between men and women or between young and old. If anything, the Hadza become more active as they age. Contrast this to the United States, where the average adult engages in less than ten minutes of moderate to vigorous activity a day, and physical activity peaks at age six. If the Hadza lifestyle reflects what human bodies are adapted for, something has gone seriously awry for the rest of us.

Regular exercisers who replace physical activity with a sedentary activity for two weeks become more anxious, tired, and hostile.

We are also the only primate to have a nuchal ligament, the strip of connective tissue that fixes the base of the skull to the spine. This ligament—shared by other running species, such as wolves and horses—keeps your head from bobbing when you run. All of these adaptations suggest that we evolved as endurance athletes.

So Raichlen put regular runners through treadmill workouts of differing intensities. Before and after each run, he drew blood to measure endocannabinoid levels. Walking slowly for thirty minutes had no effect. Nor did the most intense workout, running at maximum effort. Jogging, however, tripled the runners’ levels of endocannabinoids. Moreover, the elevation in endocannabinoids correlated with the runners’ self-reported high. Raichlen’s hunch was correct. The runner’s high is a buzz.

You just have to do something that is moderately difficult for you and stick with it for at least twenty minutes. That’s because the runner’s high isn’t a running high. It’s a persistence high.

Areas of the brain that regulate the stress response, including the amygdala and prefrontal cortex, are rich in receptors for endocannabinoids. When endocannabinoid molecules lock into these receptors, they reduce anxiety and induce a state of contentment. Endocannabinoids also increase dopamine in the brain’s reward system, which further fuels feelings of optimism.

I am not a morning person, but I have learned to drag myself out from under the covers, stumble to the kitchen for coffee, and exercise before I do anything else. For me, it’s a survival strategy. I want to face the day as the version of myself who takes over by the time I’m done with my workout: braver, more optimistic, and ready to face whatever challenges await me.

In a 2017 review of how the endocannabinoid system works in the brain, scientists identified three things that reliably amp it up: cannabis intoxication, exercise, and social connection. The three psychological states most strongly linked to low levels of endocannabinoids? Cannabis withdrawal, anxiety, and loneliness. Endocannabinoids aren’t just about not worrying and being happy; they are also about feeling close to others. Higher levels of these brain chemicals increase the pleasure you derive from being around other people. They also reduce the social anxiety that can get in the way of connecting. And just as inhibiting endocannabinoids eliminates the runner’s high, it also takes away the desire or ability to connect with others. Giving rats an endocannabinoid blocker makes them less interested in socializing with other rats. In mice, it makes new mothers neglect their pups.

One study found that on days when people exercise, they report more positive interactions with friends and family. Among married couples, when spouses exercise together, both partners report more closeness later that day, including feeling loved and supported.

In fact, he had been itching to run a study looking at whether exercising with others would lead to a bigger increase in endocannabinoids than exercising alone. But I was even more interested in another possibility—that being physically active can enhance the cooperation high and help us extract even more joy from working as a team or helping others.

It’s a puzzling marriage, running and belonging. Why do our brains so readily link physical activity and social connection? And why does the biology of the runner’s high coincide so closely with the neurochemistry of cooperation? Whatever the reason, this is how we evolved. We are able to persist, for ourselves and for one another. Whether chasing down dinner, pushing a stroller up a hill, or running errands for a neighbor, we can take joy in the effort. And the more physically active you are, the more rewarding these experiences become. That’s because one of the ways that regular exercise changes your brain is by increasing the density of binding sites for endocannabinoids. Your brain becomes more sensitive to any pleasure that activates the endocannabinoid system; it can take in more joy. This includes the runner’s high, which helps explain why people find exercise more enjoyable the more they do it. But it also includes social pleasures, like sharing, cooperating, playing, and bonding. In this way, regular exercise may lower your threshold for feeling connected to others—allowing for more spontaneous feelings of closeness, companionship, and belonging, whether with family, friends, or strangers.

Since then, numerous studies have shown that for regular exercisers, missing a single workout can lead to anxiety and irritability. Three days without exercise induces symptoms of depression, and one week of abstinence can produce severe mood disturbances and insomnia.

In laboratory studies with rats, running ten kilometers a day for one month had an effect on dopaminergic neurons similar to that of a daily dose of cocaine or morphine.

Similarly, sedentary adults who begin high-intensity training show an increase in enjoyment over time, with pleasure peaking at six weeks. One study of new members at a gym found that the minimum “exposure” required to establish a new exercise habit was four sessions per week for six weeks.

She looked for something that would get her farther from her cubicle and discovered volkssporting, German for “the people’s sports.” Volkssporting takes a noncompetitive approach to outdoor walking, hiking, cycling, swimming, and cross-country skiing. You can show up at an event any time within the start-to-finish window, participate at your own pace, and take in the scenery and the company.

Now when Haefele hears that someone is thinking about trying a first 5K but is worried about finishing or belonging, she encourages them to take the risk. “I tell them the story about my first 5K, how afraid I was, and how it literally changed my life. If I can, I will offer to go with them,” she says. “I like to throw in John Bingham’s quote, ‘The miracle isn’t that I finished, it’s that I had the courage to start.’ I get weepy when I see that. If you can just find that little bit of courage that you need to start, it will change everything.”

Exercise produces a less extreme spike in dopamine, endorphins, and other feel-good chemicals. Drugs like cocaine or heroin wallop the system, but exercise merely stimulates it, leading to very different long-term adaptations. The brain reacts to regular exercise not by suppressing activity in the reward system, but by facilitating it. In direct contrast to drugs of abuse, exercise leads to higher circulating levels of dopamine and more available dopamine receptors. Instead of annihilating your capacity for pleasure, exercise expands it.

In both animal and human studies, physical activity reduces cravings for and abuse of cannabis, nicotine, alcohol, and morphine.

In laboratory studies with rats, twenty-one days of running altered their brain stems and prefrontal cortexes—areas of the brain that control the body’s response to fear and stress—in ways that made the rats braver and better able to handle stressful situations. In humans, exercising three times a week for six weeks increases neural connections among areas of the brain that calm anxiety. Regular physical activity also modifies the default state of the nervous system so that it becomes more balanced and less prone to fight, flight, or fright. The latest research even suggests that lactate, the metabolic by-product of exercise that is commonly, but erroneously, blamed for muscle soreness, has positive effects on mental health. After lactate is released by muscles, it travels through the bloodstream to the brain, where it alters your neurochemistry in a way that can reduce anxiety and protect against depression.

Maybe it is more accurate to think of commitment, not addiction, as the primary function of the reward system. Perhaps it is this capacity that exercise taps into. From this view, our ability to get hooked reflects our tendency to get attached. Physical activity isn’t just another habit-forming drug; instead, it harnesses our capacity to form the kind of bonds that hold together our most important relationships.

In 1912, French sociologist Émile Durkheim coined the term collective effervescence to describe the euphoric self-transcendence individuals feel when they move together in ritual, prayer, or work. Durkheim believed that these activities help individuals feel connected to one another and to something bigger than themselves. We crave this feeling of connection, and synchronized movement is one of the most powerful ways to experience it.

When you participate in any physical activity—sports, dance, running, weight lifting—your moment-to-moment sense of self is shaped by the qualities of your movement. When you move with grace, your brain perceives the elongation of your limbs and the fluidity of your steps, and realizes, “I am graceful.” When you move with power, your brain encodes the explosive contraction of muscles, senses the speed of the action, and understands, “I am powerful.” When you move in a way that requires strength, your brain senses the resistance in your muscles and the force on your tendons, and concludes, “I am strong.” These sensations offer convincing data about who you are and what you are capable of. My twin sister once told me that her favorite part of a run is “the part when it’s horrible.” When I laughed, she explained, “It’s a primal feeling. I’m doing this thing that is really tough, and I’m still doing it. I’m tough.”

Research shows that high-intensity training can significantly improve outcomes following a traumatic injury or stroke, even years after the initial trauma.

R. Snyder, who conducted the most rigorous scientific analyses of hope, found that this state of mind—so crucial to our ability to persist in the face of life’s obstacles—requires three things. The first is a defined goal, that object on which hope lives. The second is a pathway to reach your goal. There must be steps you can take that lead to progress. The third is trusting that you are capable of pursuing that path. You must believe that you have the inner resources and the necessary support to take each step.

Psychologists call physical activity that takes place in a natural environment green exercise. Within the first five minutes of any physical activity in nature, people report major shifts in mood and outlook.

Even more stunning was the finding that all human brains, at rest, slip into a similar state. Neuroscientists dubbed this pattern of brain activity the default. Left to its own devices, the human mind holds imaginary conversations, replays past experiences, and reflects on the future. It especially likes to think about you, your goals in life, and your relationships with others. This default state is essential for functioning in a social world. The brain’s baseline activity is also how we remember who we are. Its inner chatter and imagery provides the awareness that you exist as a specific individual, with preferences, aspirations, and problems, one who continues across time and context. You wouldn’t want the alternative—a brain that struggles to create a coherent sense of self or place in the world. That is what happens in late-stage Alzheimer’s disease, when pathological tangles ravage the core structures of the default network. However, the default state also has a downside. For many of us, the mind’s default has a negative bias. Its most familiar habits are to ruminate on past hurts, criticize ourselves or others, and rehearse reasons to worry. The default state can also become a mental trap. In theory, when you focus on something—a conversation, a movie, work—the default mode quiets down and allows the brain to enter a state of outwardly directed attention. But people who suffer from depression or anxiety don’t make this switch as easily. They show unusually high acti...

Researchers at Stanford University sent participants out on a ninety-minute walk. Some hiked the Dish, a scenic trail in the foothills near campus, while others walked along one of the busiest streets in Silicon Valley.

After the scenic hike—but not the walk on the busy roadway—participants reported less anxiety and negative self-focused thinking. Their post-walk brain scans revealed less activity in the subgenual cortex, an area linked to self-criticism, sadness, and rumination. Individuals who suffer from depression show more activity in this part of the brain during “rest” than people who are not depressed. A walk in nature selectively silenced this part of the default state’s stream of consciousness.

As I read Rosati’s work, I started to think about how the typical default state is essentially a way to practice the social cognition skills humans developed to thrive in groups. In contrast, the alternate default state of mindfulness—one of open awareness to the environment, with a sense of curiosity and hope—maps onto the “mind” Rosati describes as foraging cognition.

Humans who find themselves disengaged from natural environments may come to know primarily the self-focused default state.

Analyses of journal entries written by people during park visits show that the most commonly used words include love, life, time, world, and God.

People who make more frequent visits to natural spaces are also more likely to feel that their lives are worthwhile. This effect is even stronger than the benefits of being in good health, and equal to being happily married or living with a partner.

In scientific papers published in microbiology and medical journals, the lack of exposure to dirt in modern society is described as “the loss of old friends”—a loss that is linked in humans to an increased risk of mental suffering, including depression.

Other than the occasional fundraiser, people don’t run ultramarathons on a treadmill. They roam wild terrain, follow the path of rivers, climb mountains, and descend through canyons. What separates even the most punishing ultra-endurance events from masochism is context. The events are not about suffering for suffering’s sake, but suffering in a natural environment that invites, almost guarantees, moments of self-transcendence. If endurance training is in part about learning how to suffer well, it helps to put yourself in surroundings that inspire awe or gratitude.

Experiencing a state of elevation during a moment of deep exhaustion provides a reminder that flashes of pure happiness can take you by surprise even when things seem the most bleak. Knowing this is possible is how we survive our worst pain. Finding a way for suffering and joy to coexist—that is how humans endure the seemingly unendurable.

When the researchers analyzed the hormones in the bloodstreams of the athletes, one hormone, irisin, was wildly elevated. Irisin is best known for its role in metabolism—it helps the body burn fat as fuel. But irisin also has powerful effects on the brain. Irisin stimulates the brain’s reward system, and the hormone may be a natural antidepressant. Lower levels are associated with an increased risk of depression, and elevated levels can boost motivation and enhance learning.

Irisin has been dubbed the “exercise hormone,” and it is the best-known example of a myokine, a protein that is manufactured in your muscles and released into your bloodstream during physical activity. (Myo means muscle, and kine means “set into motion by.”) One of the greatest recent scientific breakthroughs in human biology is the realization that skeletal muscles act as an endocrine organ. Your muscles, like your adrenal and pituitary glands, secrete proteins that affect every system of your body. One of these proteins is irisin. Following a single treadmill workout, blood levels of irisin increase by 35 percent. The Yukon Arctic Ultra required up to fifteen hours a day of exercise. Muscle shivering—a form of muscle contraction—also triggers the release of irisin into the bloodstream.

A 2018 scientific paper identified thirty-five proteins released by your quadriceps during a single hour of bicycling. Some of these myokines help your muscles grow stronger, while others regulate blood sugar, reduce inflammation, or even kill cancer cells. Scientists now believe that many of the long-term health benefits of exercise are due to the beneficial myokines released during muscle contraction.

Still other myokines decrease inflammation in the brain, which can also prevent neurological disorders and reduce symptoms of depression and anxiety. Some myokines even metabolize a neurotoxic chemical caused by chronic stress, turning it into a harmless substance in your bloodstream before it can reach the brain.

Endurance activities like walking, hiking, jogging, running, cycling, and swimming, as well as high-intensity exercise such as interval training, are especially likely to produce a myokinome that supports mental health.

When I headed to Planet Granite, I knew that I wanted to make room for fear, courage, and joy to coexist on the climb. It wasn’t until I was on the wall, climbing, that I realized other people can hold the courage and joy for you until you can find your own. I didn’t have to generate every ounce of what I needed by myself. I could expand my idea of what the container of my experience was—make it big enough to include those who had gone before me and those who were sharing it with me, even on the periphery.

The willingness to rely on others—for morale or physical support—can be a valuable lesson that extends beyond the race course.

Movement offers us pleasure, identity, belonging, and hope. It puts us in places that are good for us, whether that’s outdoors in nature, in an environment that challenges us, or with a supportive community. It allows us to redefine ourselves and reimagine what is possible. It makes social connection easier and self-transcendence possible. Each of these benefits can be realized through other means. There are multiple paths to self-discovery and many ways to build community. Happiness can be found in any number of roles and pastimes; solace can be taken in poetry, prayer, or art. Exercise need not replace any of these other sources of meaning and joy. Yet physical activity stands out in its ability to fulfill so many human needs, and that makes it worth considering as a fundamentally valuable endeavor. It is as if what is good in us is most easily activated by or accessed through movement.