Exercise is Good. But How Do We Make More Fun?

The least fun exercise experience I ever had was the 2018 Boston Marathon. I know that sounds boastful and preposterous (how can a marathon be fun?), but please bear with me because the conditions that day were so dreadful they illustrate an important point. Boston weather at the end of April is sometimes nice, sometimes chilly, sometimes warm, or sometimes rainy, but the nor’easter that battered Boston that day was unusually brutal. By 10 am, when the race began, it had been pouring steadily for hours, the temperature was a few degrees above freezing, and there was a relentless, fierce headwind that gusted up to thirty-five miles per hour.

Normally, no sum of money would entice me to run in such miserable weather, and as I obsessively checked the forecast before the race, I considered staying home despite having trained for months. On race day, however, I smeared my entire body with Vaseline, dressed in several waterproof layers, tucked a shower cap under two hats, donned supposedly waterproof gloves, encased my shoes in plastic bags to avoid getting them wet before the start, and like a lemming boarded the bus in downtown Boston to travel far out to the little town of Hopkinton, where the race begins.

The scene in Hopkinton made me think of one of those movies that depicts soldiers in the trenches before a World War I battle. The high school’s sports field, where runners wait before starting, had been churned into mud by 25,000 cold, wet, miserable marathoners. I am always jittery before a race—a mix of apprehension, anxiety, and excitement—but this time I was worried. How was I going to make it home without getting hypothermia? Yet when my appointed time came, I stood hunched in the pelting rain and biting wind behind the starting line, glumly ate my good luck blueberry muffin (a ritual), and waited for the starting gun so I could begin trudging along with thousands of other anxious, miserable runners.

The next 26.2 miles were horrid. At times, the headwind and rain were so fierce it was hard to take a step forward, my waterlogged shoes made each step sound like an elephant’s, and every inch of my body felt raw. Within a few miles, I decided that the sole reason to keep on running despite the drenching rain, puddles, and unabating wind was that not stopping was the fastest way to get home and avoid getting even colder. My primary urge on crossing the finish line was to crawl into bed as fast as possible to warm up, which is exactly what I did.

Over the next few days as I recovered physically and mentally, I thought about why I and twenty-five thousand other lunatics ran through that storm. If my goal was simply to run 26.2 miles, I could have waited until the next day and enjoyed nearly perfect weather. The only explanation I can give is that I ran for social reasons. Like a soldier in battle, I wasn’t alone but instead part of a collective doing something difficult together. The Boston Marathon has been a revered tradition since 1897 and has become even more meaningful since terrorists attacked the race in 2013. I felt I was running not just for myself but also for others, including the hundreds of thousands of spectators who braved the storm to cheer us on. Finally, shameful as it may be to admit, I ran because I didn’t want to face the social disapprobation that comes from being a coward or a quitter. Peer pressure is a powerful motivator.

And therein lies an important lesson about why we exercise. Because exercise by definition isn’t necessary, we mostly do it for emotional or physical rewards, and on that horrid April day in 2018, the only rewards were emotional—all stemming from the event’s social nature. For the last few million years humans rarely engaged in hours of moderate to vigorous exertion alone. When hunter-gatherer women forage, they usually go in groups, gossiping and otherwise enjoying each other’s company as they walk to find food, dig tubers, pick berries, and more. Men often travel in parties of two or more when they hunt or collect honey. Farmers work in teams when they plow, plant, weed, and harvest. So when friends or CrossFitters work out together in the gym, teams play a friendly game of soccer, or several people chat for mile after mile as they walk or run, they are continuing a long tradition of social physical activity.

I think there is a deeper evolutionary explanation for why almost every book, website, article, and podcast on how to encourage exercise advises doing it in a group. Humans are intensely social creatures, and more than any other species we cooperate with unrelated strangers. We used to hunt and gather together, and we still share food, shelter, and other resources, we help raise one another’s children, we fight together, we play together. As a result, we have been selected to enjoy doing activities in groups, to assist one another, and to care what others think of us. Physical activities like exercise are no exception. When we struggle with fatigue or lack of skill, we encourage and help one another. When we succeed, we praise each other. And when we think of quitting, being in a group can deter us. My hardest workouts have always been in groups, and I have often shown up for a run or a workout only because I had previously arranged to meet a friend.

Of course, exercise is also sometimes enjoyable without socializing. A solitary walk or run can be meditative, and working out while listening to podcasts or watching TV in the gym (a distinctly modern phenomenon) can be diverting. But for most people exercising with others is more emotionally rewarding. For this reason, sports, games, dancing, and other types of play are among the most popular social activities, and regular exercisers often belong to clubs, teams, and gyms. To entice customers, the gym down the street has a big sign, “Never Work Out Alone!” Some of the most popular, effective ways to exercise are group workout experiences like CrossFit, Zumba, and Orangetheory.

Exercise can also make us feel good, which helps make it enjoyable. After a good workout I feel simultaneously alert, euphoric, tranquil, and free from pain—not unlike taking an opioid. Actually, natural selection did adopt this drug-pushing strategy by having our brains manufacture an impressive cocktail of mood-altering pharmaceuticals in response to physical activity. The four most important of these endogenous drugs are dopamine, serotonin, endorphins, and endocannabinoids, but in a classic evolutionary design flaw these primarily reward people who are already physically active.

Dopamine. This molecule is the linchpin of the brain’s reward system. It tells a region deep in the brain “do that again.” Evolution thus geared our brains to produce dopamine in response to behaviors that increase our reproductive success including having sex, eating delicious food, and—surprise—doing physical activity. But there are three shortcomings in this reward system for today’s non-exercisers. First, dopamine levels go up only while we exercise. So they don’t get us off the couch. Worse, dopamine receptors in the brain are less active in people who haven’t been exercising than in fit people who are regularly active. And to add insult to injury, people who are obese have fewer active dopamine receptors. Consequently, non-exercisers and obese individuals must struggle harder and for longer (sometimes months) to get their receptors normally active, at which point they can cause what is sometimes considered “exercise addiction.” If you exercise regularly, you know the feeling when you have to endure several days without exercise: you get twitchy, irritable, and crave physical activity to satisfy your hungry dopamine receptors. In extreme cases exercise addiction can be a serious dependency, but the term is usually applied to a normal, harmless, and generally beneficial reward system.

Serotonin. This still mysterious neurotransmitter helps us feel pleasure and control impulses, but it also affects memory, sleep, and other functions. Our brains produce serotonin when we engage in beneficial behaviors like having physical contact with loved ones, taking care of infants, spending time outdoors in natural light, and, yes, exercising. Elevated levels of serotonin induce a feeling of well-being (the drug ecstasy exaggerates this feeling by boosting serotonin levels sky-high), and we become better at controlling nonadaptive impulses. Low serotonin is thus associated with anxiety, depression, and impulsivity. Although some people with depression take pharmaceuticals to maintain normal serotonin function, exercise has been shown to be often as effective as any prescription. However, as with dopamine, non-exercisers are at risk of having lower serotonin activity, making them more vulnerable to being depressed and unable to overcome the impulse to avoid exercise, which in turn keeps serotonin levels low.

Endorphins. Endorphins are natural opioids that help us tolerate the discomfort of exertion. The body’s own opioids are less strong than heroin, codeine, and morphine, but they too blunt pain and produce feelings of euphoria. Opioids allow us to go for a long hike or run without noticing our muscles are sore and our feet have blisters. They may also contribute to exercise addiction. But, once again, there is a catch. Although their effects can last for hours, endorphins aren’t produced until after twenty or more minutes of intense, vigorous activity, making them more rewarding for people who are already fit enough to work out that hard.

Endocannabinoids. For years, endorphins were thought to cause the infamous runner’s high, but it is now evident that endocannabinoids—the body’s natural version of marijuana’s active ingredient—play a much greater role in this phenomenon. Despite causing a truly pleasurable high, this system has little relevance for most exercisers because it usually takes several hours of vigorous physical activity before the brain releases these mood- and sensory-enhancing drugs. Further, not everyone has the genes that make a runner’s high possible. I suspect the runner’s high evolved primarily to increase sensory awareness to help hunters track animals during persistence hunting.

While these and other chemicals released by exercise help us exercise, their drawback is they mostly function through virtuous cycles. When we do something like walk or run six miles, we produce dopamine, serotonin, and other chemicals that make us feel good and more likely to do it again. When we are sedentary, however, a vicious cycle ensues. As we become more out of shape, our brains become less able to reward us for exercising. It’s a classic mismatch: because few of our ancestors were physically inactive and unfit, the brain’s hedonic response to exercise never evolved to work well in persistently sedentary individuals.

So what should we as a society and you and I as individuals do? How can we make exercise more fun and rewarding especially if we are out of shape?

First and foremost, let’s stop pretending exercise is necessarily fun, especially for habitual non-exercisers. If that describes you, start by choosing types of exercise you either enjoy the most or dislike the least. Just as important, figure out how to distract your mind while you exercise with other things you find fun. At the very least, such diversions will help make the exercise less disagreeable. Commonly recommended, sensible methods to make exercise more fun (or less unfun) include:

• Be social: exercise with friends, a group, or a good, qualified trainer.
• Entertain yourself: listen to music, podcasts, or books, or watch a movie.
• Exercise outside in a beautiful environment.
• Dance or play sports and games.
• Because variety is enjoyable, experiment and mix things up.
• Choose realistic goals based on time, not performance, so you don’t set yourself up for disappointment.
• Reward yourself for exercising.

Second, if you are struggling to exercise, it is useful to remember how and why exercising takes time to become enjoyable or less unpleasant. Because we never evolved to be inactive and out of shape, the adaptations that make physical activity feel rewarding and become a habit develop only after the several months of effort it takes to improve fitness. Slowly and gradually, exercise switches from being a negative feedback loop in which discomfort and lack of reward inhibit us from exercising again to being a positive feedback loop in which exercise becomes satisfying.

So, yes, exercise can become more rewarding and fun. But let’s not deceive ourselves or others. No matter what we do to make exercise more enjoyable, the prospect of exercising usually seems less desirable and less comfortable than staying put.

__________________________________

From Exercised: Why Something We Never Evolved to Do Is Healthy and Rewarding by Daniel Lieberman. Used with the permission of Pantheon Books. Copyright © 2021 by Daniel Lieberman.