How the Body Knows Its Mind_The Surprising Power of the Physical Environment to Influence How You Think and Feel

by Sian Beilock

  Not only did the children perform better on the cognitive tests when they exercised rather than rested, but their brain functioned more fluently after exercise. Neural activity emanating from frontal and parietal brain areas, activity known to reflect our ability to control our attention (something of dire importance in school), was enhanced after the kids had exercised compared to when they had been sedentary.

  For a long period in human evolution, our ancestors lived as hunter-gatherers. Moving across plains and mountains to hunt game and gather nuts and berries was necessary to our survival. This means that our minds and bodies evolved in the setting of an active lifestyle. Physical activity seems to be programmed into our genes.5 But the amount of activity that young kids, adults, and senior citizens get today is usually well below what we are genetically predisposed to do. The consequences of a sedentary existence are evidenced by ill health in body and mind. Children who are more physically fit perform better on academic tests. Elderly people who are active have a lower risk and incidence of memory loss and loss of other important cognitive functions. Providing kids with opportunities to be active and to exercise helps hone their mental as well as their physical muscles. And a regular exercise regimen for adults helps prevent mental decline.

  As testing becomes an increasingly larger part of our academic culture and school budgets continue to be tightened, recess, gym class, and physical activity are targeted for elimination in the mistaken belief that getting kids to spend more time in the classroom is a cheaper and better way to boost test scores than giving them breaks to run around. Yet discoveries in brain science tell a different story. If we want to produce kids with the most brain health, ability to focus their attention, and superior thinking and reasoning skills, then we need to add a fourth “r,” recess, to the curriculum. We also need to make sure that kids are getting the opportunity to exercise outside of school, as it’s not atypical for a child to have no physical activity outside of school hours. Knowing that the fitness of the body has a big impact on the fitness of the mind provides us with a clear prescription for children: get them moving.

  Adults

  Physical activity is also key to a better brain after adolescence, although we know less about how fitness relates to brain function in young adults. Our cognitive functioning is at its peak in our late teens through our thirties. Of course, even at the peak of our mental capacities, we don’t always perform at our best. We have all experienced situations where the stress of an important test, speech, or job interview robs us of the brainpower we would normally have to perform well. Exercise can help us get access to all our cognitive resources.

  Short bouts of exercise specifically benefit the functioning of a network of brain regions that include the prefrontal cortex, the parietal cortex, and the hippocampus, which support thinking and reasoning and especially working memory. You can think of working memory as a kind of mental scratch pad that allows you to work with whatever information is in your consciousness. It helps you focus on what is immediately relevant to a task and to screen out what is irrelevant. Working memory is one of the major building blocks of IQ.6

  An important detail about working memory is that it is limited. We have only so much of this brain resource at our disposal. In pressure-filled situations—taking a test, pitching a client, or interviewing for a job—we have even less. Stress drains our working memory, but exercise jump-starts the brain regions that support working memory, so it improves thinking, elevates mood, and reduces stress. And this exercise boost tends to be biggest for those people who come to the table with lower amounts of working memory to begin with.

  Some people naturally wield more brainpower, more working memory than others. One way for those with less working memory to perform as if they have more is by taking part in a short bout of exercise. Ben Sibley and I discovered the advantage of exercise for those with less working memory several years ago, when we were both on the faculty at Miami of Ohio University. Ben had recently found that a short bout of exercise had an immediate and positive impact on people’s ability to focus their attention. Since focusing on some information while keeping irrelevant information out of consciousness is at the heart of working memory, we wondered if the benefits of exercise might be most extreme for those people who had the most trouble focusing to begin with.7

  We began by inviting about fifty undergraduates to Ben’s lab in the basement of the kinesiology building at the university. We first asked them to take a number of tests that gauged their working memory. An important point about measuring working memory is that it doesn’t much matter what people are holding in mind; what’s important is that we can measure their ability to focus on some bit of information when they are distracted.

  In one task, called the Operation Span Task,8 participants were asked to solve aloud a math problem that appeared on a computer and was followed by a word:

  Is (10 ÷ 2) − 3 = 2? SEA

  Is (10 ÷ 10) − 1 = 2? CLASS

  Is (5 × 2) − 2 = 8? PAINT

  Is (4 × 1) − 1 = 3? CLOUD

  Is (6 ÷ 3) + 3 = 5? PIPE

  After reading aloud and solving each math problem, the students were told to read the word aloud and remember it. Then the math problem and the word disappeared from the screen. Deciding whether the math problem is correct was not the main goal of this task; we wanted to know how good they were at remembering the words at the end. After a number of math-word pairs (usually between three and five), we asked the students to recall all the words in the order in which they appeared. Even though the students knew they were going to have to recall the words, they didn’t know when the recall task was coming, so they had to keep the words in mind while they were doing the math problems. Holding information in memory while doing something else is really what working memory is all about.

  After getting measures of working memory, we asked everyone to run for thirty minutes on a treadmill set up in the lab. The running was self-paced, but we asked everyone to try to work out at about 60 to 80 percent of what they would consider their max. After that, we asked them immediately to take part in some more working memory tasks, but we replaced the math problems and words with new ones so they couldn’t use what they remembered from the first tests to help them out on the second.

  What we found was that those folks who came to the table with less working memory to begin with benefited most from a short but moderate bout of exercise. This finding was exciting because, it’s not just that adults differ in their working memory from each other, working memory is also something that changes across the lifespan. Young children tend to have less working memory because brain areas such as the prefrontal cortex, which support our ability to hone our attention, are still developing. Working memory also tends to decline in senior citizens. This means that exercise programs that target younger and older people might be especially beneficial, boosting the power of developing and waning working memories.

  Being active and working up a sweat can even help you negotiate better. In a study recently conducted at MIT’s Sloan School of Management, researchers found that people negotiated better in a deal for a used car or even a compensation package for a new job when they got their heart rate up by walking at a quick pace on a treadmill.9 But there was a catch. Exercising led to better negotiating only when folks went into the negotiations from the outset confident in their powers of persuasion. For those who came to the table already flustered, pushing up their heart rate with a short bout of exercise led to worse deal making (both in terms of their feelings about the negotiation and how they objectively performed). How we perform has a lot to do with how we interpret our bodily reactions. Confident negotiators viewed their beating heart as a sign they were thriving, but those who dreaded negotiating thought their physiological state was a sign that they were failing, so they performed poorly. Whether we view our racing heart and sweaty palms as a sign of excitement or anxiety has a lot to do with whether we will clutch or choke.

  Thankfully, we c
an all learn to view our ramped-up symptoms in a more positive light. For several years, the psychologist Jeremy Jamieson and his colleagues at the University of Rochester have been exploring the benefits of having people reappraise their higher heart rate or other physical stimulation in potentially stressful situations, such as test taking, public speaking, and having an anxiety-producing social encounter. For instance, Jamieson and his colleagues have shown that getting students to think of a racing heart or sweaty palms as an energy resource can actually help them perform better on tests. Most striking, when provided with tips for rethinking their physical signs, people’s views of potentially stressful situations change. If they were nervous to begin with, they still report the situation as demanding, but they now believe that they possess better ability to cope compared with folks who don’t get the reframing tips.10

  Of course, moderation is key in using exercise to boost thinking, reasoning, and negotiating. While some physical activity boosts working memory—especially for those with less to begin with—and may make you better able to cut a favorable deal, more than an hour of intense physical activity before an intellectual challenge is not necessarily advantageous. Long bouts of exercise that lead to dehydration, for example, can deprive the brain of important nutrients you need to function at your best. But exercise can boost your ability to think on the fly and perform optimally, especially in response to stress. When asked directly whether exercise is beneficial before conducting negotiations, one of the MIT researchers involved in the treadmill study cautioned, “I wouldn’t suggest doing a marathon.”11

  Long-term fitness is also associated with enhanced thinking and reasoning in young adults. In a recent study that tracked more than a million eighteen-year-old men in the Swedish army, better fitness was related to higher intelligence and more job success. The fitter the soldier, the higher his IQ and the more likely he was to go on to a successful career than his less fit counterparts.12 Physical fitness is linked to enhanced functioning in important frontal and parietal areas of the brain, which help support working memory and our focus of attention,13 so it’s easy to see how physical fitness could translate into mental fitness. Being fit allows you to recruit more brainpower when high levels of mental effort are required.

  Fitness does more than simply give people extra mental computing power. Exercise can also enhance the type of creative smarts for which companies like Apple and Google are known.14 Not coincidentally, these companies are very into fitness, with in-house gyms and trainers for employees, and they’re famous for coming up with new ways to use a product, such as the iPhone and Gmail. Exercise helps the brain see things in new ways. Success in the workplace is not always about putting your nose to the grindstone and pushing through masses of data, paper, and problems. Sometimes it’s about knowing when to take a step back so that you can see something from a different perspective, find an unplumbed corner of the market, enhance an old tool in a unique way.

  Short bouts of aerobic exercise help a neurotransmitter, dopamine, circulate in our brain. Dopamine plays an important role in many aspects of brain function, such as control of movement, sensitivity, feelings of gratification, and focus of attention. A gradual decline in dopamine generally occurs with aging, but this decline is significantly smaller in exercising animals, even if an animal doesn’t begin exercising until later in life. Dopamine also plays an important role in creativity, our ability to think flexibly about a problem from multiple perspectives. An exercise program helps stave off the natural decline in dopamine.15

  Yet another reason to lace up those sneakers and get out for a walk or run during lunch is that our body and our fitness give us more positive views of the world around us. Compared to their fit counterparts, people who are out of shape and have poor fitness levels judge hills to be steeper. People who experience chronic pain when walking think objects are farther away than folks of the same age who don’t have difficulty walking. Older adults who become less fit and less mobile as they age estimate a hallway to be longer than do fit college students.16 If being unfit leads to judging distances and hills as less traversable, this could lead you to be more sedentary. A vicious cycle emerges, in which an unfit body influences the mind and makes it harder to get moving in the first place.

  Later in Life

  Before the fitness gurus Richard Simmons and Bob Greene held sway, there was Jack LaLanne, who is often called the father of the modern-day fitness movement. As a teenager, he discovered the power of nutrition and exercise, which gave his life meaning and direction after he had been through a rough childhood. In 1936 in Oakland, California, LaLanne opened what might have been the first health club, complete with a gym, juice bar, and health food store. (He later sold his chain to Bally.) In the 1950s, The Jack LaLanne Show first aired locally in northern California and then went national. It still runs today on ESPN Classic. LaLanne preached the benefits of exercise and good nutrition at a time when no one—not even those in the medical profession—paid much attention to the influence of the body on how people felt, thought, and behaved. A walking testament to the impact of exercise on physical health, LaLanne was incredibly fit, with bulging biceps, a wry smile, and an engaging wit. As he famously remarked, “I can’t die. It would ruin my image.”

  LaLanne did eventually pass away, in 2011, at the age of ninety-six. Yet even in his final years he continued to exercise regularly, for up to two hours a day, swimming and lifting weights in his home on California’s central coast. In his sixties he made the treacherous swim from Alcatraz to Fisherman’s Wharf in San Francisco while pulling a thousand-pound boat. In his seventies he performed another amazing feat in the water, this time swimming over a mile and a half in the Long Beach Harbor while pulling boats that held more than seventy people. LaLanne set an example for aging people, encouraging them to exercise and proclaiming that gyms are not just for the young.17

  Jack LaLanne may have been one of the first advocates of the power of exercise, but he isn’t alone in believing that fitness is important for people of all ages. You can see people in their forties, fifties, and sixties circling the local track or walking the mall in the morning, but you can also find athletes in their seventies, eighties, and nineties. Masters athletic programs can be found around the country. You have to be at least thirty-five to take part in masters competitions, but some of the most exciting competitors are much older. It’s estimated that some fifty thousand people worldwide call themselves masters track and field athletes.

  Consider Olga Kotelko, a ninety-three-year-old Canadian track athlete, who has a habit of setting world records. It’s true that there aren’t that many women competing in her age group, but Kotelko is killing her competition. At the World Masters Games in Sydney, Australia, in 2009, her 23.95 seconds time for the 100-meter dash put her squarely with the finalists who were two age brackets younger.

  People eighty-five and older are the fastest growing segment of the world’s population, so researchers are turning to them for clues to what promotes health and longevity. Most of the work targeting these individuals looks at what foods they eat and their social lives. But in Kotelko’s case, scientists are quite interested in how long-term exercise alters the body and the mind.

  Unlike LaLanne, who found physical fitness in his teenage years, Kotelko didn’t start masters track and field until she was in her late seventies.18 She grew up on a farm in Saskatchewan, where she was always an active child, feeding chickens and milking cows rather than playing sports. Organized sports weren’t readily available, and the ones that were around weren’t open to girls. After she retired from her career as a teacher, she got involved in slow pitch softball, and when her softball career was ending in her early seventies, a friend suggested that she might like track and field: it would give her something to do and could be a great way to meet other retired people in her area. She found a coach, and the rest is history—literally—with Kotelko breaking world records at every turn of the track.

  Kotelko’s case illus
trates that exercise prolongs life and promotes health. Scientists have taken samples of her muscle fibers and found that exercise seems to have rolled back time in terms of her cellular health. Usually mitochondria, cell structures that generate energy for cells and muscle, decay in senior citizens, but there is little sign of that in Kotelko. Scientists are extremely interested in why her body doesn’t seem to be aging very quickly. They also want to know how exercise prolongs mental health. Striking new research shows that exercise does indeed benefit cognitive functioning in later life. There are clear differences in brain health in fit older adults compared with their more sedentary counterparts, and these differences carry consequences for thinking and reasoning as well as for memory.

  Several years ago, scientists averaged the results from roughly two dozen studies in which researchers had randomly selected adults over the age of fifty-five to participate in an exercise training program or to serve as a control group (which did not exercise). Despite all of the differences in the exercise programs that people took part in, when the results were tallied, there was a clear pattern: the exercise groups had greater cardiovascular fitness and mental fitness. Exercise clearly helped improve their working memory too. Older adults who had taken up an exercise regimen performed markedly better in tasks in which they had to focus attention, concentrate, or think quickly.19