If the benefits of physical activity were distilled into pills, everyone would take it. Research shows that exercise can improve almost every aspect of health: promoting sleep, strength, and mental health, while reducing the risk of chronic disease and premature death. What's more, studies have shown that exercising can have a positive impact even in a very short period of time and without the need for equipment or fancy gym memberships.
Still, most people don't get enough exercise. According to data published in 2023, less than one-third of U.S. adults receive** the recommended amount of physical activity in their free time: at least 20 minutes of moderate-intensity aerobic exercise per day (think brisk walking), plus muscle-strengthening training (such as resistance training) several times a week.
Why is it so difficult to get people to do something that is so good for them? Physical limitations and health issues are undoubtedly a factor for many people, as more than half of American adults suffer from some sort of chronic disease. Modern life is also largely to blame, with long sedentary workdays and infrastructure often making it easier to hop in a car than to walk or bike somewhere. Research has long shown that people who don't earn much money are less likely to exercise than wealthy people, in part because they may live in areas with relatively little space that are safe and enjoyable.
But research shows there's another obstacle that affects us all: our brains don't want us to exercise.
For most of the human being, people have to engage in physical activity in order to perform the basic functions of life, such as finding or growing food. Humans have evolved to tolerate high levels of activity, but also tend to take breaks when possible to conserve energy in case exercise is necessary or enjoyable, explains human evolutionary biologist Daniel Lieberman, author of Exercise: Why Things We Never Evolved Are Healthy and Beneficial.
In other words, hunter-gatherers aren't jogging to burn extra calories. From an evolutionary point of view, "it's going to be a stupid thing to do," Lieberman said. "You waste your energy on things that won't do you any good. ”
Lieberman says that as a society, we don't move much in our daily lives anymore, but the evolutionary instinct to conserve energy remains. "That kind of reluctance, that kind of reluctance, that kind of saying'I don't want to [exercise].'The sound is completely normal and natural," he said.
Matthieu Boisgontier, an associate professor and physical activity researcher at the University of Ottawa, demonstrated this phenomenon in a 2018 study. When connected to a brain activity monitor, one can control a digital avatar. They were told to transfer their avatars from images of sedentary behavior that popped up on computer screens to images of physical activity. Boisgontier and his colleagues found that avoiding sedentary lifestyles required more brain power, suggesting that "we have an automatic tendency" to choose to relax rather than move, he said.
This conclusion has been repeated in studies. For example, studies have shown that people have always chosen to take escalators instead of stairs. This natural instinct isn't a bad thing in itself, it's just that modern life has given us so many opportunities to succumb to our preference for rest that "we've reached an extreme point where it's no longer good for our health," Boisgontier said.
Many people also subconsciously harbor negative feelings about sports, which can be traced back to childhood, says Jackie Hargrees, a senior lecturer in sport and exercise psychology at Leeds Beckett University in the United Kingdom. Hargreaves said that in youth sports teams, an awkward or unpleasant experience in physical education class can make a person avoid exercising as an adult.
Sometimes it's also a matter of faith. Studies have shown that people who think they are capable of exercising are more likely to stick to a regular routine, while people who think the opposite may have a hard time finding consistent motivation, says behavioural scientist Stefanie Williams, who works with a British organisation that translates health research into practice.
Feeling good about your abilities is essential to finding the motivation to exercise, says Sam Zizzi, a sports psychologist at West Virginia University. He recommends starting small – perhaps walking just a few minutes a day at first – and building that progress over time. Observing peers doing what you want to do, especially if they're the same age, gender, or health condition as you, can also help you realize that you can accomplish it too, Williams says.
Lieberman adds that a counterintuitive way to build confidence is to simply recognize the ways your brain is making you fail. "When people work hard, they're told they're lazy, or they have a problem," Lieberman said, "when in reality, people who work out purely for fitness are people who go against their natural instincts." Replacing guilt and shame with self-compassion – and an understanding of how the human brain works – can go a long way.
The same goes for redefining what exercise is. You don't need to spend an hour lifting weights in the gym; Many studies have shown that even spending a few minutes a day dancing in the kitchen or weeding in the garden can be good for your body and mind. "It's not about going out and doing intense competitive sports," Hargreaves said. "It's about moving" and finding a truly enjoyable way to move.
Finally, Zizzi suggests making workouts "serve a dual purpose" – perhaps planning a bike ride with friends so your workout doubles as a social outing, or turning an existing work meeting into a walk-and-talk. Interweaving exercise with what you already want or need to do can make it easier to ignore the parts of your brain that tell you it's best to park yourself on the couch, Zizzi says.