Relationship between alertness, brain and body performance
A RESEARCHER IN WALES IS CURRENTLY trying to improve the stationary bike performance of a group of volunteers using a program of vigorous training, 45 to 90 minutes a day, five days a week . . . playing a cognitively challenging computer game. Training the brain, he believes, will translate into improved physical performance. However the results turn out, the fact that such an experiment isn’t simply laughed out of the lab shows how much our understanding of the link between brain and body has changed in the past decade.
For decades, exercise physiology has struggled to pin down the limits of physical performance by studying the heart, lungs, and muscles of athletes. New experiments show that the brain plays a fundamental and often surprising role. And it also works the other way around: exercise shapes your brain, stimulates growth, and enhances memory and cognition—and some types of exercise are better than others.
If my brain is tired, will my body’s performance suffer?
Many people spend their workdays sitting on a chair in front of a computer, with physical exertion limited to an occasional stroll down the hallway. From a purely physical perspective, it’s hard to imagine a cushier existence. But if you head to the gym after work, you might notice that your performance suffers when you’ve spent the afternoon wrestling with a particularly complicated problem. In 2009, researchers from Bangor University in Wales published the first rigorous investigation of this phenomenon in the Journal of Applied Physiology. They asked 16 volunteers to ride a stationary bicycle to exhaustion under two different conditions: once after taking a challenging 90-minute cognitive test and once after passively watching 90 minutes of documentaries about trains and cars. Sure enough, the subjects who had been using their brains reached exhaustion after 10 minutes and 40 seconds on average—a full minute and 54 seconds before the movie-watchers.
It’s possible that thinking actually burns up enough energy to affect your physical performance: the test-takers recorded slightly higher heart rates (65 beats per minute) compared with the movie watchers (62 beats per minute), likely due to the brain’s heightened demand for glucose. But the data taken during the cycling test suggest that this wasn’t a significant factor. The two groups produced identical physiological responses to exercise, as measured by quantities such as heart rate, oxygen consumption, and blood lactate. The only difference was in their subjective rating of how hard the exercise felt: right from the moment they started pedaling, the mental-fatigue group rated their perceived exertion a few points higher on a scale of 6 to 20. Both groups stopped pedaling when their perceived exertion hit 20—which means the mental-fatigue group stopped earlier, with lower physiological measures of fatigue than the control group.
For the researchers, this finding offers powerful evidence that our traditional understanding of exhaustion as the result of reaching some physical limit in the body’s capabilities is flawed. “Overall, it seems that exercise performance is ultimately limited by perception of effort rather than cardiorespiratory and musculoenergetic factors,” they wrote. Intriguingly, our perception of effort during exercise is regulated in a part of the brain called the anterior cingulate cortex—which is precisely the part of the brain activated by the 90-minute cognitive test used in the experiment. This suggests that a bout of hard thinking might disrupt our sensation of physical effort, even though the muscles themselves are completely unaffected. The most eyebrow-raising implication of this study is that it might be possible to improve physical performance through brain training, without leaving your armchair, by postponing fatigue of the anterior cingulate cortex. The Bangor research team is in the process of testing this remarkable hypothesis.
For elite athletes, the study highlights the benefits of a period of mental relaxation before particularly hard workouts or competitions. In general, though, the researchers are careful to point out that exercising after work is still a great idea: the effects of mental fatigue will have only a minor effect on moderate exercise, and the workout is a great source of stress relief. Still, it’s worth bearing in mind that if you’ve been pulling an Einstein at work, you might need to cut yourself some slack at the gym.
Does it matter what I’m thinking about when I train?
For many people, heading out for a run or a bike ride offers a mental break—a chance to think about the events of the day, or about nothing at all, while the legs navigate on autopilot. But for those who are looking to lower their best race times, a growing body of research suggests that what’s going on in your head during training sessions can make a big difference in how effective those sessions are. “It’s not just physical intensity that counts, it’s mental intensity,” says Joe Baker, a researcher at York University in Toronto.
Over the past few decades, psychologists have reached the remarkable conclusion that your level of achievement in fields ranging from sports to music to science depends less on natural talent than on the number of hours you spend doing “deliberate practice,” a term coined by Florida State University cognitive psychologist Anders Ericsson. In one of his seminal studies, Ericsson found that the virtuosos at major philharmonics had averaged 7,400 hours of deliberate practice by the age of 18; typical professionals had averaged 5,300 hours; and those who ended up teaching violin instead of performing had spent only 3,400 hours.
Not all practice is “deliberate” practice. Rather than simply repeating tasks over and over, it involves setting specific goals and monitoring how well you perform, constantly adjusting and improving your technique. This seems like the opposite of most training for endurance sports—heading out the door and running for an hour at a comfortable pace, say, with no specific goals, minimal feedback, and no thought about technique.
But top endurance athletes rely on a number of training techniques that do fit the definition of deliberate practice. In a study of the training practices of elite runners by University of Ottawa researchers Bradley Young and John Salmela, what separated the highest-performing group from their less accomplished peers was how much they incorporated elements like interval training, tempo runs, and time trials, all of which require ongoing attention to pace and other feedback. “High quality and high intensity, rather than long slow distance, is at the heart of deliberate practice,” Baker says.
Deliberate practice also involves monitoring your training and progress over the course of weeks and months and making appropriate adjustments, rather than just doing what you’ve always done. A study of Ironman triathletes by Baker and his colleagues found that the most experienced athletes planned their training year carefully, taking regular easy weeks to allow their bodies to recover so that they could steadily build their training to a peak. The novices, in contrast, simply trained as hard as they could until cumulative fatigue or injuries forced them to back off, resulting in less training overall.
Traditionally, researchers have divided the mental strategies used by endurance athletes into “associative” and “dissociative.” When you’re associating, you’re concentrating on the task at hand: your breathing, your pace, and so on. When you’re dissociating, you’re thinking about anything but the task at hand: the weather, or last night’s TV show. A series of studies over the past few decades has demonstrated that faster runners have more associative thoughts during competition than their slower rivals, who have more dissociative thoughts. “But there’s an important message,” Baker notes. “No one has suggested that top runners associate all the time.”
Similarly, psychologists don’t suggest that you try to make all your training deliberate. Even the virtuoso violinists, famed for spending 10 or more hours a day practicing, managed to average only a few hours a day of deliberate practice. For most people, the majority of exercise time should remain relaxed, a mental diversion. But adding a segment of deliberate practice a few times a week could make a big difference in your race performance. And there may be an added bonus. Young and Salmela’s study of elite runners produced one very unexpected result: they found that the types of training that took the most effort and concentration—the most deliberate, in other words—were rated as the most enjoyable sessions by the runners. So deliberate practice may be hard, but it’s satisfying—especially on game day.
Does listening to music or watching TV help or hurt my workout?
In a study published in 2009, researchers at Britain’s Liverpool John Moores University secretly sped up or slowed down music by 10 percent and observed the effect on subjects riding exercise bikes. Sure enough, like marionettes on musical strings, the riders unconsciously sped up or slowed down. The study confirms what gym-goers have known for a long time: music can have a significant impact on your exercise performance, and its influence extends far beyond the simple psych-up provided by motivational lyrics.
The dominant theory about why music boosts exercise performance is that you have a limited ability to pay attention to the information your senses gather. Focus on sounds and sights, the theory goes, and you’re less aware of the distress signals your muscles are sending you. A 2007 study by Vincent Nethery of Central Washington University offered support for this theory. Subjects exercising at a constant workload reported less discomfort when listening to music or watching a video. In contrast, an earlier study by Nethery found that subjects wearing earplugs and a blindfold reported greater levels of discomfort during exercise, presumably because they had nothing to focus on except their fatigue.
The British study adds a new twist by controlling the factors that usually confound studies of music and exercise: personal preferences, volume, pitch, duration, genre, lyrics, and so on. The researchers chose six tracks that “reflected current popular taste among the undergraduate population” and combined them into a single 25-minute program, then digitally altered it to create faster and slower versions without changing the pitch. The subjects exercised to the three versions with a week in between each session, and none of them noticed the differences in tempo. A 10 percent difference is quite small, lead researcher Jim Waterhouse says: “Compare the interpretations of Beethoven symphonies by Toscanini and Klemperer, for example.”
The link between musical tempo and effort confirms the findings of several earlier studies, albeit with greater rigor. What’s new, though, is the fact that the subjects reported greater enjoyment and higher levels of perceived exertion after the sped-up session. In other words, the faster music didn’t simply distract them from their discomfort; it motivated them to happily endure greater levels of discomfort.
This result—along with many other apparently conflicting studies in this area—suggests that the music-as-distraction theory ignores broader psychosocial factors, says Costas Karageorghis of Brunel University in Britain. He identifies rhythm, “musicality,” cultural impact, and the external associations of the song as the four key factors influencing a listener’s response. As a result, attempts to find universal effects of particular pieces, styles, or even speeds of music on exercise are doomed. Instead, Karageorghis says, people should tailor their play lists to their personal preferences, and gyms should play different types of music by the cardio machines (faster) and by the weights (motivational lyrics).
Interestingly, some researchers have found preliminary evidence that watching TV or videos is likely to slow your workout down, suggesting that too much distraction not only dulls your pain but also distracts you from putting forth an honest effort. The difference between video and music may have something to do with the active attention required to watch a video—holding your head in the right position, for example—compared to passively listening to music, Nethery says. “It may also highlight the value of rhythm associated with music,” he adds. That would mean listening to a podcast or to talk radio would be more akin to watching a TV show than listening to music, though this hypothesis has yet to be tested.
In 2007, headphones were banned at all major road races in the United States. Although that ban has since been relaxed, listening to music while running or biking remains a serious safety concern on roads and paths with traffic—be it cars, bikes, or simply other pedestrians. On empty trails where no one else is around, it’s still crucial to be aware of your surroundings, particularly for women exercising alone. The performance-boosting effects of music are best enjoyed indoors.
Of course, even the “wrong” distractions are still beneficial if they get you out the door or keep you exercising longer. But it’s worth being aware of the effects. Try paying attention to how different songs make you feel and perform during different exercises, and you may learn how to give yourself a boost when you most need it.
Will I perform better under pressure if I focus harder?
When you’re lining up a crucial putt, the last thing you want to hear is an impatient jerk in the foursome behind you yelling “Hey buddy, could you hurry it up a bit?” But new research suggests that the jerk might be doing you a favor. Psychologists and neuroscientists are finding that, when you perform complex motor sequences that you’re very familiar with, concentrating too much on the details of the task makes your performance worse. Too much concentration is what causes choking on the putting green or at the free-throw line—and it’s why a bit of distraction can be a good thing.
Even skills as simple as tying your shoes begin as a sequence of separate actions that you consciously execute in a certain order, explains Clare MacMahon, a Canadian researcher now at Victoria University in Australia. As you master the skill, the steps become combined into a single action that is stored in your “procedural” memory, beyond conscious control. “If you then try to consciously monitor yourself—‘Make two bunny ears, one bunny goes around the tree’ and so on—you break the skill back down into its components,” MacMahon says, “and you end up looking like a novice again.”
MacMahon was a co-author of a 2002 study in the Journal of Experimental Psychology that compared novice and expert soccer players dribbling a ball while either focusing on their technique or being distracted by sounds. Novices performed better when they focused on technique, but experts—for whom technique had progressed to subconscious control—performed better when they were distracted. As an added twist, the researchers repeated the experiment with the subjects using their non-dominant foot. In this case, both novices and experts performed better while focusing on technique: even the best players weren’t truly expert with their non-dominant feet.
Sian Beilock, the University of Chicago researcher who was the lead author of the soccer study, published another study in 2009 in which novice and expert golfers were asked to putt either as quickly as possible while maintaining accuracy or taking as much time as they wanted. Again, novices and experts responded differently. The novices performed best when they took their time, while the experts performed best when they were told to hurry up. “It’s really clear that paying too much attention to your step-by-step actions can disrupt fluidness,” Beilock says. “And this is what happens under stress, what people call ‘choking.’”
Other researchers have extended these results to basketball, hockey, and even darts. More surprisingly, a 2009 study in the Journal of Sports Sciences found that focusing too intently was even disruptive in running, a task whose mechanics most people consider fairly straightforward. Researchers found that runners focusing on their form or their breathing consumed more oxygen and burned more energy than runners who simply watched their surroundings. If nothing else, this is a reminder that walking and running are complex tasks that your subconscious mind executes very efficiently. (“If you don’t believe walking is complex, why can’t we program a robot to walk normally?” Beilock points out.)
Of course, you still need your conscious mind to master skills in the first place. But once you’ve become proficient, it’s worth remembering that, when the pressure is on, scrunching up your forehead and focusing on your mechanics is more likely to hurt you than help you. And you can also use this knowledge as an offensive weapon, MacMahon points out. If you’re playing tennis and your opponent aces you, compliment them: “Wow, that was a great serve. Are you doing something with your wrist?”