By Gretchen Reynolds
In a year filled with COVID-related hopes, setbacks, advances and losses, the most vital exercise science of 2021 provided a reminder that for many of us, our bodies and minds can strengthen, endure and flourish, no matter our circumstances. If we move our bodies in the right ways, a growing body of evidence suggests we might live with greater stamina, purpose and cognitive clarity for many years to come. And it may not take much movement.
In fact, some of the year’s biggest fitness news concerned how little exercise we might be able to get away with while maintaining or even improving our health. A study from January, for instance, showed that just five minutes of intense calisthenics substantially improved college students’ aerobic fitness and leg strength. Another series of studies from the University of Texas found that four seconds — yes, seconds — of ferocious bicycle pedaling, repeated several times, was enough to raise adults’ strength and endurance, whatever their age or health when they started.
Even people whose favorite workout is walking might need less than they think to reach an exercise sweet spot, other new research suggested. As I wrote in July, the familiar goal of 10,000 daily steps, deeply embedded in our activity trackers and collective consciousness, has little scientific validity. It is a myth that grew out of a marketing accident, and a study published this summer further debunked it, finding that people who took between 7,000 and 8,000 steps a day, or a little more than 3 miles, generally lived longer than those strolling less or accumulating more than 10,000 steps. So keep moving, but there’s no need to fret if your total doesn’t reach a five-figure step count.
Of course, exercise science weighed in on other resonant topics this year, too, including weight. And the news there was not all cheering. Multiple studies this year reinforced an emerging scientific consensus that our bodies compensate for some of the calories we expend during physical activity, by shunting energy away from certain cellular processes or prompting us unconsciously to move and fidget less. A study from July, for example, that examined the metabolisms of almost 2,000 people concluded that we probably compensate, on average, for about one-quarter of the calories we burn with exercise. As a result, on days we exercise, we wind up burning far fewer total calories than we might think, making weight loss that much more challenging.
On the other hand, exercise seems essential for weight maintenance, according to other research this year. A new scientific analysis of participants from TV weight-loss contest “The Biggest Loser” found that those who exercised the most in the years after the program ended were the least likely to have regained all of the pounds they shed during the show.
Exercise also has a disproportionate effect on our odds of enjoying a long, healthy life. According to one of the most inspiring studies this year, overweight people who started working out lowered their risk of premature death by about 30% even if they remained overweight, with exercise providing about twice as much benefit as weight loss might.
Exercise enhances our brain power, too, according to other memorable experiments from this year. They showed physical activity fortifying immune cells that help protect us against dementia; prompting the release of a hormone that improves neuron health and the ability to think (in mice); shoring up the fabric of our brains’ white matter, the stuff that connects and protects our working brain cells; and likely even adding to our creativity. In a nifty study from February, physically active people tended to dream up more inventive ways to use car tires and umbrellas, a standard test of creativity, than people who seldom moved around much.
Taken together, this year’s exercise neuroscience research makes “a strong case for getting up and moving” if we hope to use our brains with ongoing clarity and in imaginative ways deep into our golden years, as one of the researchers said to me.
Still, the study that stuck with me most this year had less to do with the myriad ways exercise remodels our bodies and brains and more with how it might shape our sense of what matters. In the study, which I wrote about in May, active people reported a stronger sense of purpose in their lives than inactive people.
“A sense of purpose is the feeling you get from having goals and plans that give direction and meaning to life,” the study’s lead researcher told me. “It is about being engaged with life in productive ways.” The study found that exercise amplified people’s purposefulness over time, while simultaneously, a sturdy sense of purpose fortified people’s willingness to exercise. In effect, the more people felt their lives had meaning, the more they wound up moving, and the more they moved, the more meaningful they found their lives.
It’s a result worth remembering as we look ahead with wary optimism. So stay healthy, active and in touch in 2022, everyone. Here’s to a happy new year!