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Excerpted from The Expectation Effect: How Your Mindset Can Change Your World by David Robson with permission from Henry Holt and Company. Copyright © 2022 by David Robson.
The power of the mind-body connection has long been known among professional athletes.
The middle- and long- distance runner Paavo Nurmi (1897-1973)—a nine-time Olympic gold medallist nicknamed the Flying Finn—expressed as much when he said, “Mind is everything; muscles, pieces of rubber. All that I am, I am because of my mind.”
This is also the philosophy of Eliud Kipchoge of Kenya, arguably the greatest marathon runner of all time. “I always say I don’t run by my legs, but I run by heart and my mind,” he explained. “What makes a person run more is their mind. If your mind is calm, and well concentrated, then the whole body is controlled.”
Scientists are now catching up with this thinking. Recent findings may help professional athletes win world records, but they are even more relevant for reluctant exercisers who struggle to maintain a fitness regimen. By adopting the right mindset, even a devoted couch potato may enjoy more gain, and less pain, from their workouts.
Mind over muscle
Much of this new understanding stems from studies of the placebo effect. Consider the research on caffeine—a muscle stimulant that is thought to enhance performance in many sports. In one study, bodybuilders were given a shot of a bitter-tasting liquid, which they were led to believe contained a high concentration of caffeine. In reality it was a dose of decaf—but they still managed to increase the number of repetitions by around 10 percent above their previous limit.
Other researchers have examined the influence of expectations on participants’ “maximum aerobic capacity” (VO2 max)—the peak oxygen consumption during intense exercise. To find out if positive feedback could alter this basic measure of fitness, researchers at the University of Nevada, Las Vegas, asked a group of participants to undergo two VO2 max tests. Although the first test was accurately measured, some were given false positive feedback about their performance. This resulted in a significantly better result on a second VO2 test a few days later. In other words, how fit someone appeared changed according to how fit they thought they were.
Our expectations of our physical abilities interplay with our genetic disposition for exercise, according to a paper published in 2019. The scientists first performed a genetic test to identify whether their participants were carrying a certain version of the CREB1 gene, which is thought to reduce people’s aerobic capacity and increase body temperature during exercise. The test was real, and the researchers kept a record of the results. The outcome given to participants, however, was random, creating expectations that they either were or were not “naturally” good at exercise. Those with the negative expectations showed reduced stamina, with lower air flow in and out of the lungs and the transfer of oxygen and carbon dioxide. On some of these physiological measures, the effects of expectations appeared to exert more of an influence than the actual gene type did.
Some of the most striking expectation effects concern our perceptions of our fitness outside of the gym. Many everyday tasks can strengthen the body, even though they look nothing like a typical workout. According to groundbreaking research, the meanings that we attach to those activities may determine whether or not we reap the full benefits of exercise.
The existence of “invisible exercise” should not be a surprise—our understanding of it dates back to the very first study to examine the benefits of physical activity. Soon after World War II, the British physiologist Jeremy Morris wanted to understand why some people are more prone to heart disease than others.
Men working on London’s buses proved to be the perfect population to study. Drivers spent most of their day sitting, while conductors climbed up and down the stairs to collect fares and help passengers with their luggage. Although this was relatively gentle exercise, Morris found that the daily activity roughly halved the bus conductors’ risk of heart failure.
Morris’s findings inspired an avalanche of further research on the benefits of exercise. The much-touted recommendation that we should aim for 150 minutes of moderate exercise (or 75 minutes of vigorous activity) per week can be traced back to those bus conductors. But many of us are still not clear about what actually counts as moderate or vigorous exercise, and that is important when it comes to the formation of our fitness mindsets.
To compare the intensity of different activities, physiologists use a quantity known as “metabolic equivalents” (METs). Moderate exercises are between 3 and 6 METs, and vigorous exercises anything above 6 METs. Many everyday activities and pastimes meet these requirements:
|Washing the floor||3|
|Making the bed||3.3|
|Carpentry (e.g., hammering nails)||3|
|Mowing the lawn||6|
|Walking the dog||3|
|Outdoor play with children||5.8|
How many of us play with our children or dance the night away without even realizing that we’re working out? At the very least, a greater appreciation of these kinds of activities should lead us to be more positive about our level of fitness—a changed expectation that could reconfigure the prediction machine so that other, more formal workouts feel like less of a strain.
Even more remarkably, this shift in mindset might determine the long-term benefits of the activities themselves, according to a study by Alia Crum and Ellen Langer at Harvard. By thinking of everyday activities as exercise, rather than work, we can become healthier.
The participants were cleaners from seven different hotels. Crum and Langer suspected that few of these cleaners would be aware of the sheer amount of exercise that their job entailed, and, given the power of expectation to shape our physiology, that this might prevent them from gaining the full benefits of their daily workout. To test the idea, the scientists visited four of the hotels and gave the cleaners information about the kinds of physical activity that count as exercise, and then offered some details about the energetic demands of the cleaners’ work, which, over the course of the week, should easily add up to the surgeon general’s exercise recommendations.
A month later, the scientists visited the cleaners again to measure any changes in their health. Despite reporting no alterations to their diet or increased physical activity outside work, the cleaners who received this information had lost about two pounds each, and their average blood pressure had dropped from elevated to normal. The shift in expectation—and the meaning that the cleaners ascribed to their work activities—had changed their bodies, while the cleaners at the remaining three hotels, who had not received the information, showed no difference.
It was a relatively small study—and there was always the possibility that after they’d been given the information, the cleaners had put a bit more “oomph” into their work. But a follow-up by Crum, who is now at Stanford, and her colleague Octavia Zahrt provides much more compelling evidence that people’s expectations really can influence the long- term benefits of exercise through the mind-body connection. Their study used data from health surveys monitoring more than 60,000 people for up to 21 years. Crum and Zahrt found that the “perceived physical activity” of the participants—whether they felt they did more or less exercise than the average person—could predict their risk of mortality, even after the researchers controlled for the amount of time the subjects said they actually spent exercising, and other lifestyle factors, like diet.
Importantly, some of the participants in these surveys had worn accelerometers for part of the study period—yet the influence of their perceived physical activity remained, after the researchers had taken these objective measures of physical activity into account. Overall, people who took a more pessimistic view of their fitness were up to 71 percent more likely to die during the surveys, compared with those who thought they were more active than average—whatever the status of their actual exercise routine.
Summing up the relevant evidence to date, a recent review paper concluded that our expectations of exercise can shape the perceived exertion, mood, gains in self-esteem, cardiorespiratory fitness and blood pressure—all important outcomes from any workout.
What this might mean for you
There are many ways that we can apply these expectation effects ourselves.
The first step is to be honest about your current assumptions. You might have formed negative beliefs about your inherent aptitude to fitness, based on bad experiences in gym classes; if so, you could try to question whether they reflect an objective truth—and remind yourself that everyone has the potential to improve their fitness, no matter what the baseline is.
Secondly, you can try to reframe the feelings of exercise itself. For many people, being out of breath and sweaty triggers negative patterns of thinking—the beliefs that you are “hopeless” and “weak” and are destined to fail. Instead, remind yourself that aches and pains are a sign you are building the strength of your muscles, increasing blood flow and expanding your lungs.
Thirdly, you should avoid “upward comparisons.” Instagram and TikTok are full of “fitspiration” accounts—but studies suggest that looking at these pictures before a workout can result in worse body image and greater feelings of exertion during exercise.
We can’t achieve immediate miracles when applying this research, but even modest expectation effects can make it much easier to keep to your fitness goals. The end result will be a longer, happier, healthier life—a much better prize than a gold medal.
David Robson is an award-winning science writer based in the United Kingdom. A graduate of Cambridge University, he previously worked as an editor at New Scientist and a senior journalist at the BBC. His writing has appeared in the Guardian, the Atlantic, Men’s Health, the Psychologist, the Washington Post, and many other publications. His first book, The Intelligence Trap, was published in 2019 and has been translated into fifteen languages.