Move it or lose it.|
“Strength of mind is Exercise, not Rest.” —Alexander Pope |
The Effects of Exercise |
Research is catching up with folk wisdom. From Homer (“Too much rest itself becomes a pain”) to Shakespeare (“The labor we delight in physics pain”) to Alexander Pope, the contributions of physical activity to mental performance have been touted. But not until recently have research findings supported these claims. This chapter visits some of these findings.
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TOPIC 18.1 |
Jean Pierre Changeux (1997), professor at the Collège de France and Institute Pasteur, and Christopher Henderson, of the Center for Neurobiology and Behavior at Columbia University, found that simple movement of the muscles stimulates the growth of axons, which carry messages between neurons. The number of axons is directly related to intelligence, and people (infants as well as adults) who move about more benefit from greater axonal development. Less movement results in fewer axons. In recent support of Changeux’s findings, Carl Cotman and team at the University of California at Irvine show (Quartz and Sejnowski, 2002, p. 250) that regular exercise increases production of neurotrophins in the hippocampus. Moreover, a study of 500 schoolchildren found that those who spent an hour each day in gym class performed better on intelligence tests than those who were inactive, a finding that has been replicated in dozens of studies.” Hence, the couch-potato syndrome is associated with lesser intelligence.
Applications
Move it or lose it.
Encourage physical activity from the cradle to the grave. Even people confined to wheelchairs or with limited mobility should move whatever they can. (Contributed by Jane Howard)
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TOPIC 18.2 |
Aerobic (“with oxygen”) activity is also called “cardio” because it provides cardiovascular conditioning. Our breathing controls the amount of oxygen transported to the muscles so they can burn fuel to move. Aerobic exercise is a constant moderate-intensity workout. The body engages large muscle groups that consume oxygen at a rate at which the cardiovascular system can replenish muscles with oxygen, allowing the person to continue exercising.
Fitness can be measured by the volume of oxygen you can consume while exercising at your maximum capacity. More precisely, we measure the VO2 max, which is the maximum amount of oxygen in milliliters you can use in one minute per kilogram of body weight. Fit people have higher VO2 max values and so they can exercise more intensely than those who are not as well conditioned. You can increase your VO2 max by working out at the intensity that raises your heart rate to between 65 and 85 percent of its maximum for at least 20 minutes three to five times a week. You can calculate VO2 max using this formula: at the conclusion of exercising, your pulse should be 220 minus your age times 0.65 (or 0.8 for athletes). For me, that would mean a pulse of about 102 heartbeats per minute. This formula is intended for the average person (about two-thirds of the population).
Mentally, aerobic exercise has several remarkable effects:
1. It clearly improves speed of recall; it is not clear whether aerobic exercise has any effect on the quality of mental functioning or the amount of recall.
2. It releases endorphins, the neurotransmitters that relax us into a state of cortical alertness. This is not the only way to reach cortical alertness (other relaxation methods will work as well), but it is certainly one way. Johns Hopkins’s Dr. Solomon Snyder and others are concerned over the lack of substantive research on the so-called runner’s high, claiming that the increased endorphins in the blood after running never reach the brain. Calling this connection an urban legend, they contend that the association was an accident caused by the simultaneous popularity of running and the discovery of endorphins. On the other hand, Arne Dietrich (American University of Beirut) has found that a minimum of 20 minutes of aerobic exercise releases significant levels of the cannabinoid anandamide in your bloodstream, the same euphoria-producing chemical associated with marijuana. So you must bear with the initial discomfort of aerobic exercise in order to get the ultimate benefit of the runner’s high. (No pain, no gain.) We are awaiting clarification. Meanwhile, run on, and enjoy it.
3. As reported in a National Institute of Mental Health study of over 1,900 individuals, people with little or no recreational activity are twice as likely to have depressive symptoms as people who regularly do aerobic exercise.
4. In the 1990s we learned that aerobic exercise increases the number of neurotrophins (agents that stimulate the growth of nerve cells) available to the brain and nervous system, according to the work of Carl Cotman, director of the Institute for Brain Aging and Dementia at the University of California, Irvine. In a later study, Cotman also found that exercise elevates BDNF (brain-derived neurotrophic factor), which is an important member of a family of proteins that maintains cell infrastructure in the brain. John J. Ratey, MD, clinical associate professor of psychiatry at Harvard Medical School, identifies this as Miracle-Gro for the brain (p. 40), linking thought, emotions, and movement.
5. William Greenough, a professor at the Beckman Institute (University of Illinois) has determined that aerobic exercise results in an increase in capillaries around the neurons in the brain. This translates into more blood and oxygen reaching the brain.
6. Arthur Kramer, a research psychologist who is also with the Beckman Institute, has established that a 45-minute water aerobics class three times a week, lasting for 10 weeks, in people 63–82 years old, results in improved, faster reaction times. He further avows that declines in reaction time appear to be related to declines in fitness more than to aging. The last three studies were summarized in Brink (1995).
7. Young people with higher aerobic fitness as measured by the VO2 max show greater ability to behave safely while multitasking, as in crossing a busy intersection while using a cell phone. Such higher fitness levels are associated with heightened alertness. Note: Only 6 percent of high schools offer a daily physical education class (Ratey, 2006, p. 19).
Recent studies add:
• Water exercise continues to be an excellent modality, particularly for populations not well suited for land exercise.
• Deep-water running is an excellent alternative or supplement to treadmill running, in that the large upper leg muscles show similar impacts.
• In a long-term study, the two-year effects of water exercise indicate that older adults may benefit from increased confidence performing physical activities, in addition to the strengthening benefits.
Another series of studies concluded that hunger is inhibited when (1) the brain contains high levels of glucose and serotonin and (2) the blood contains high levels of epinephrine, norepinephrine, and dopamine. Exercise tends to raise levels of all five of these neurotransmitters.
There are three factors to keep in mind when designing an aerobic exercise regime:
1. Intensity, which is the speed and power required for an activity. Walking is lower in intensity than running.
2. Duration, where the American College of Sports Medicine (ACSM) recommends 20–60 minutes of continuous aerobic activity. Of course, this depends on the person’s fitness level and the advice of a physician. You should start at a duration that is safe and without undue fatigue, even if it is less than 10 minutes! Training can increase as health and safety permits.
3. Frequency, or the number of times per week.
Ideally, the routine would progress to five days per week of continuous activity using the large muscle groups at the intensity where your breathing was increased to the point that you could talk but not sing. For maximum benefits, John Ratey recommends 30–40 minutes of moderate-intensity exercise five or six days per week.
A few words of caution. First, exercise appears to be more effective in preserving mental function that could decline with aging, rather than in improving function among people who have always been sedentary and who, later in life, try to make up for lost time. For example, “according to a 2012 article on the website Science Daily,” David Bucci at Dartmouth finds that the effects of exercise are different for adolescents and adults in areas of memory and the brain. He concludes, “The implication is that exercising during development, as your brain is growing, is changing the brain in concert with normal developmental changes, resulting in your having more permanent wiring of the brain in support of things like learning and memory. It seems important to [exercise] early in life” (Dartmouth College, 2012). Second, the benefits of exercise are associated with long-term exercising, rather than brief episodes of several months’ duration. And we lose the benefits of having exercised when we stop.
Applications
For maximum benefit, exercise after the most stressful part of the day is over and before a period in which mental alertness is required or desired. For some of us, this may have to be an either-or situation. High stress nullifies the effect of aerobic exercise. You must exercise again after a stressful episode. (Stress releases the toxin cortisol, and aerobic exercise dissipates it. For more discussion of this relationship, see topic 33.1.)
Avoid exercising immediately before bedtime, unless that is the only time you can exercise. It tends to interfere with sleep.
Don’t ride when you can walk; don’t sit when you can stand.
Learn deep-breathing exercises (breathe in for six counts, hold for four counts, expel for six counts) and isometric exercises for times when you must be sedentary for long periods.
Ensure that you and all your family members get aerobic exercise (brisk walking or its equivalent) for 30–45 minutes a day, at least five days per week.
Exercise your influence to ensure that your local schools are providing daily aerobic exercise for students. According to the President’s Council on Physical Fitness and Sports, only 36 percent of kids in grades 1–12 get a daily 30-minute aerobic workout. (Forty percent of five-year-olds already show at least one heart disease risk factor!)
For the maximum benefit of aerobic exercise, engage in the following nonstop activities for an average of 30 minutes, five times weekly: running, bicycling, jogging, brisk walking, distance swimming, skating, jumping rope, rowing, treadmill, dancing, and so forth. Realize that many exercises, while being healthy, are, for a variety of reasons, nonaerobic—for example, basketball (not continuous), sprinting (too brief), golf (low exertion). For a more complete listing, see Bailey (1991).
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TOPIC 18.3 |
Norman Cousins (1989) writes of studies that emphasize how choice influences the degree of health benefits of exercise. If an individual is forced to engage in an exercise against his will, the health benefits tend to be reduced. Cousins cites the ineffectiveness of walking on a treadmill, as he had been directed, versus his dramatic improvement after he chose instead to walk on a track. Apparently the stress of engaging in exercise that is not of our choosing can outweigh its health benefits. As another example of this, my wife’s first husband loved playing tennis, especially during hot summer afternoons. She hated it and often sustained headaches when she was pressured into playing with him. Eighteen years later, she still avoids tennis. (See chapter 33 for further discussion of the importance of personal control in managing stress.)
James Gavin, director of the graduate program in applied human sciences at Concordia University in Montreal, has developed a model for prescribing exercise regimens based on personality characteristics. This is related to Cousins’s notion of choice in that Gavin maintains that some kind of exercise will appeal to everyone. In his book The Exercise Habit (1992), he includes a seven-dimension psychosocial scale to help match exercise with personality.
Related to these findings is the work of Charles Emery, professor of psychology and medicine at Ohio State University, who found (Prevention, September 2004) that middle-aged and older cardiac patients (both men and women) experienced cognitive performance boosts when using upbeat music (especially Vivaldi’s Four Seasons) to accompany their workouts on a treadmill. Those exercising to upbeat music performed twice as well on verbal fluency measures (e.g., how many words can you list in the next two minutes that start with the letter w?) as those who exercised unaccompanied. Emery argues that the upbeat musical accompaniment appears to provide an extra boost by organizing mental resources. I suspect that the music may force a quicker tempo that makes more oxygen available to the brain, as well as making the exercise more playful, less punishing, hence less stressful. I am not ready to argue that the music in and of itself caused the boost in performance. However, ’tis a small bother to exercise to upbeat music, so why not? For me, I’ll take Bach’s Brandenburg Concerti—the fast movements, that is.
Applications
Avoid engaging in an exercise for its health benefits if you don’t really have a positive attitude toward it. Choose an exercise that appeals to you. I’ve had many friends try to encourage me to take aerobic dance classes. For me, personally, that is a distasteful proposition—I don’t like the music most aerobics instructors use to motivate their participants, don’t like the follow-the-leader format, don’t like the emphasis on dressing out for the event, don’t like having to drive there (all this, even though our younger daughter is a jazzercise instructor, and we certainly love her!). Instead, I walk. I love to walk. I could write an essay on why I like walking, but I’d better resist. . . .
Read Gavin, The Exercise Habit (1992).
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TOPIC 18.4 |
In a study of 16 addicted smokers and 18 regular snackers, Robert Thayer (1989) reported that brisk 10-minute walks reduced their cravings and improved their mood. The walking smokers reported an average increase of 50 percent over the control subjects in the time before they craved a smoke. Those in a poor mood who walked instead of snacking reported significantly higher and longer elevations of mood than nonwalking snackers. In subsequent studies, Thayer and others have found that an intensive workout (a 45-minute jog) has no more effect on mood than a 10-minute brisk walk.
Gregory Mondin, Boise Veterans Administration Medical Center sport psychologist, tested 10 volunteers who were accustomed to working out six days a week. After skipping two workouts, all experienced one or more of various mood swings, including anxiety, depression, confusion, and that “blah” feeling. Resuming their exercise routine fixed things right up.
Michael Gallagher, vice-dean of the School of Osteopathic Medicine at the University of Medicine and Dentistry of New Jersey in Newark, has found that participating in regular, nonjarring (that is, not jogging) aerobic exercise (such as swimming, using a stationary bicycle, or walking) improves the chances of avoiding migraine headaches among those prone to suffer from them. Apparently, one precursor of migraines is muscle tension, and the endorphins released by aerobic exercise decrease that tension.
One explanation of exercise’s benefits comes from the research of the University of Georgia’s Rod Dishman, professor of exercise science, who has identified an increase in epinephrine levels as a result of sustained exercise. Epinephrine permeates the locus coeruleus, which is a kind of junction box for the several brain functions associated with mood and emotion. As a result, Dishman theorizes, the increased levels of epinephrine serve to lubricate the individual’s mechanism for coping with stress. Interestingly, he points out, several of the antidepressant drugs are associated with elevated levels of epinephrine. Mark Sothman, vice president for academic affairs and provost, Medical University of South Carolina, says that aerobic exercise, in effect, provides a workout for the body’s internal communication system so that when stress occurs, one’s physical coping mechanisms are in good order. Both Sothman and Dishman have confirmed these relationships in animal and human experiments (they are summarized in the July 1996 APA Monitor).
Dr. Madhukar Trivedi, of the University of Texas Southwestern Medical Center, Dallas, published a pilot study in 2006 describing how patients not responding to antidepressant medication dropped scores significantly on a depression test (by 10.4 points on a 17-point scale!) after 12 weeks of exercise. Working with the Cooper Institute, eight patients completed the exercise program. Five of those eight went into full remission. Although this is a small number of participants, when we consider that exercise regulates all of the neurotransmitters targeted by antidepressants, it is practical to conclude that for some people, exercise works to help depression.
Applications
During prolonged sedentary periods or periods of stress, take a brisk 10-minute walk every couple of hours—outdoors, if possible.
During coffee breaks, try taking a 10-minute walk outside instead. The resulting natural arousal will equal or better the arousal you would get from more caffeine and stale office air. Walk by yourself or with a group, whichever pleases you.
If not even a 10-minute walk is possible, at least do a few jumping jacks, sit-ups, push-ups, isometric exercises, or stretches, or just simply meditate, as a way to release the tension build-up accompanying lack of exercise.
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TOPIC 18.5 |
John Raglin, an Indiana University sports psychologist and kinesiologist, has tagged a condition resulting from continuing high athletic performance and workouts as the “staleness syndrome” (APA Monitor, April 1996; see also his “Overtraining and Staleness” in Singer, Murphey, and Tennant, 1993). Around 5–10 percent of athletes who train intensely develop a pattern of irritability, tension, anger, lack of desire to train, sleep disturbance, muscle soreness, decrease in immune function (and accompanying susceptibility to infectious diseases), depression, perceptual changes (for example, routines may suddenly seem harder), and general mental instability. The result is an abrupt halt in the ability to perform. Even short breaks or reduced workout schedules don’t relieve the pattern. Only complete rest for several months appears to restore the previous performance level, yet these levels are not always regained. About 60 percent of elite long-distance runners will suffer from staleness at some point. Staleness also affects about 30 percent of sub-Olympic athletes who train seriously, as well as some recreational athletes who train seriously.
Raglin has found that staleness can be avoided by monitoring athletes’ moods. In an experiment with swimmers, researchers administered a mood test, the Profile of Mood States (POMS) (McNair, Lorr, and Droppleman, 1971), and varied the swimmers’ workout schedules to keep their moods within an optimum range. For the first time in 10 years, no team member developed staleness. Raglin (personal correspondence) reports that scores on the POMS correlate nicely with relevant biological changes, such as muscle glycogen, cortisol, and neuromuscular function, suggesting that the psychological mood changes are symptoms of physical changes. Unfortunately, many athletes misinterpret the staleness symptoms and mistakenly choose to work out harder (with even worse results) rather than to lighten up.
Applications
If you train intensely or are associated with athletes who train intensely, consider taking this overtraining test developed by Raglin, at www.runnerspb.com/p/overtraining-test.html.
Raglin suggests that because athletes in intense training tend to be honest about physical symptoms and mood states, a simple seven-point scale that measures soreness, general well-being, and perceived exertion can serve as well for self-monitoring as the 72-item, five-minute POMS.
Staleness in exercise bears a remarkable similarity to burnout at work. See the discussion of burnout in topic 33.4 for further understanding and recommendations concerning this phenomenon.
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TOPIC 18.6 |
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A concussion occurs when the head sustains a strong blow that results in loss of consciousness, however brief. After the blow, the brain hits the skull in a “counterblow.” In more severe cases, often as the result of twisting the neck during the blow, pressure is put on the brain stem, where basic involuntary life functions are controlled. Bleeding or other damage may occur. Often, people who sustain a concussion cannot remember the events surrounding the blow.
Neuropsychologist Michael Collins, Henry Ford Health System in Detroit, reported (in Journal of the American Medical Association, September 8, 1999) that, in a study of 393 college football players, those who had suffered two or more concussions were significantly more likely to evidence problems with headaches, sleep, and concentration. They scored significantly lower on tests that measured word learning, thinking speed, and ability to handle complex tasks. Furthermore, those players who had learning disorders in addition to the two or more concussions performed even lower.
In a related study, amateur soccer players fared worse on tests of memory and planning ability than other amateur athletes. Blows to the head, including “headers,” accounted for the difference. In both the football and soccer studies, “concussion” was defined not just as being “knocked out,” but also to include blows to the head that resulted in dizziness, headache, confusion, difficulty with balance or memory, or even personality change (see description of grades 1 and 2 below).
Outside the realm of organized sports, similar effects are coming to light: roller coasters, no less! Since 1991, at least 13 documented cases of severe brain injury have been attributed to theme park rides traveling at speeds as high as 90 miles per hour, a speed creating G forces above five, which is greater than that experienced by astronauts on shuttle takeoffs. Injury in these cases comes not from being hit, but rather from the kind of whiplash that happens when severe forces cause the brain to slosh against the inner wall of its carrier. Look for symptoms such as vomiting, pupils that are different sizes, confusion, seizures, coma, muscle weakness, or unusual walking patterns.
Adrienne Witol, an inpatient psychologist at the Medical College of Virginia, and Frank M. Webbe, a professor in the School of Psychology at Florida Institute of Technology, studied 60 male soccer players who were at least 15 years of age and who played five times per week. They determined that players who engaged in “heading” the ball more frequently performed less well on tests of visual searching, attention, mental flexibility, general IQ, and facial recognition than did players who headed the ball infrequently or never. Because the study was not longitudinal, the researchers do not know if the loss of mental function associated with heading the ball is reversible once the players no longer participate in soccer.
Applications
The American Academy of Neurology has established guidelines for three levels of concussion (note that the examples are drawn from the sports world, which happens to have the highest incidence of concussion):
Grade 1: No perceptible loss of consciousness; mild confusion and loss of coordination; symptoms are gone in 15 minutes. (Check every 5 minutes for symptoms; if they have cleared after 15 minutes, the individual may resume normal activity. If a player in a sport has suffered multiple grade 1 concussions, she may return to play only after a neurological assessment and one symptom-free week.)
Grade 2: No perceptible loss of consciousness; mild confusion and loss of coordination; symptoms last more than 15 minutes. (Remove a player from the game; examine him frequently; conduct a brief neurological assessment. The player may return after one week with no symptoms after rest or exertion. If a player suffers multiple grade 2 concussions, he may return only after being symptom-free for two weeks.)
Grade 3: Loss of consciousness for either seconds or minutes. (Take the patient by ambulance for an emergency neurological examination. With brief unconsciousness, a player may return to a game after one symptom-free week; with longer periods of unconsciousness, the player may return after two symptom-free weeks.) These last two guidelines are for adults. The guidelines differ for young people.
If a young person in an athletic situation has a concussion, typically she should not resume athletics for three months. Immediately after the concussion, the person should be still and quiet. Brain injury rates are higher for those who have sustained prior concussions with unconsciousness. Repeated concussions have a cumulative effect on one or more mental functions. With uncomplicated concussions, full recovery is typical.
For a complete copy of the American Academy of Neurology guidelines, visit their site at www.aan.com/professionals/practice/guideline/index.cfm.
Stay current with information on concussions by visiting the National Institute of Neurological Disorders and Stroke website: www.ninds.nih.gov. Information is also available from the Brain Injury Association: 800-444-6443 or website www.biausa.org.
If you are a soccer player or associate with soccer players, support the practice of “heading” on an extremely limited basis, if at all. Or wear soccer headgear. Heads are not made for bashing.
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TOPIC 18.7 |
Charles Garfield (1984) has described a process that guides athletes into superior performance using mental training. In fact, he reports that one can reduce one’s physical training (for example, running laps) and, by replacing physical training with mental training, increase levels of performance. His process includes visualization, mental rehearsal techniques, goal setting, and volitional self-awareness.
In a separate development that clearly relates to Garfield’s approach, researchers at the OptiBrain Center, a joint project of the University of California, San Diego, and the Naval Health Research Center, have identified the insula (or insular cortex; see illustration in Appendix A, Cross Section—viewed from front; left) as a common ingredient among high-performing athletes such as NBA stars and Navy SEALs. The insula is the seat of interoception—that quality of being aware of internally generated sensations. In short, stellar athletes have insulas that are more active and that have more gray matter than lesser performers. This advantage gives them the ability to use their limited resources better—when to hold or expel breath, when to be hypercalm, when to be hypervigilant. The good news: apparently the insula can be trained to be more active through an age-old regimen called mindfulness (see discussion at topic 20.29). The Buddhists were onto something—mindfulness isn’t just religion, it is a key to peak performance.
Applications
If you desire to be a peak athletic performer, read Garfield’s Peak Performance.
Another “mental training” approach to peak athletic performance has been developed by Carol Ann Erickson and Arlene Berkman of the Brain-Body Center for Performance Enhancement, Scarsdale, New York (914-725-2458). See more at eggballboys.blogspot.com/2007/06/concentrations.html.
The Internet is replete with resources for mindfulness training. When OptiBrain publishes its findings, I am sure you will see mindfulness training purveyors popping out of the woodwork. In the meantime, check the Internet for what is available, and get on OptiBrain’s mailing list. Visit optibrain.ucsd.edu.
A good review of effective mindfulness practices is Davis, D. M., and J. A. Hayes (2011). “What Are the Benefits of Mindfulness? A Practice Review of Psychotherapy-Related Research.” Psychotherapy 48(2), 198–208. A pdf version is available at: www.apa.org/pubs/journals/features/pst-48-2-198.pdf.
SUGGESTED RESOURCES
Brink, S. (1995, May 15). “Smart Moves.” U.S. News & World Report, 76–85.
Changeux, J.-P. (1997). Neuronal Man: The Biology of Mind (L. Garey, trans.). Princeton, N.J.: Princeton University Press.
Coop, R. H. (1993). Mind over Golf: Play Your Best by Thinking Smart. Old Tappan, N.J.: Macmillan.
Garfield, C. A. (1984). Peak Performance: Mental Training Techniques of the World’s Greatest Athletes. Los Angeles: Tarcher.
Gavin, J. (1992). The Exercise Habit. Champaign, Ill.: Human Kinetics.
Morgan, W. P. (Ed.). (1997). Physical Activity and Mental Health. Washington, D.C.: Taylor & Francis.
Neeper, S. A., F. Gomez-Pinilla, J. Choi, and C. W. Cotman (1995). “Exercise Raises Brain Neurotrophins.” Nature, 373, 109.
Ratey, J. (2008). Spark: The Revolutionary New Science of Exercise and the Brain. New York: Little, Brown.
Singer, R. B., M. Murphey, and L. K. Tennant (Eds.) (1993). Handbook of Research on Sport Psychology. Old Tappan, N.J.: Macmillan.
Spirduso, W., L. Poon, and W. Chodzko-Zajko (2008). Exercise and Its Mediating Effects on Cognition (volume 2). Champaign, IL: Human Kinetics.
Websites
American College of Sports Medicine: www.acsm.org
American Council on Exercise: www.acefitness.org/?creative=14787453084&gclid=CKqh36K2xbQCFQcHnQodkgIApA
Let’s Move—First Lady Michelle Obama’s initiative: www.letsmove.gov