Exercise and the mind

Fitness enthusiasts usually say that they feel better after vigorous exercise. Some runners even tell of a heightened transcendence of time and space during the run. Close to 75 percent report that they have experienced this "runner's high" at least a few times, and some say that they experience the high nearly 30 percent of the times they run.¹

Since the beginning of time many have believed in the cerebral satisfaction of exercise. The Greeks maintained that exercise made the mind more lucid. Aristotle started his Peripatetic school in 335 B.C., so named because of his habit of walking while lecturing to his students, who walked with him. Plato and Socrates also practiced the art of peripatetics, as did the Ordo Vagorum, or walking scholars of Rome. When com posing the talks that gave rise to Methodism, John Wesley found that brisk walks of 20 and 30 miles a day put "spirit unto his sermons." ²

Former United States president John F. Kennedy perpetuated the Greek ideal of a "healthy mind in a healthy body" with his statement that "physical fitness is not only one of the most important keys to a healthy body; it is the basis of dynamic and creative intellectual activity. Intelligence and skill can only function at the peak of their capacity when the body is strong. Hardy spirits and tough minds usually inhabit sound bodies." ³

Results of mental state

For a long time we have known that psychological states can have a profound effect on one's physical health. Many studies have shown that being chronically anxious, depressed, or emotionally distressed is associated with the deterioration of health. In 1985 Dr. D. E. Girard reviewed the literature on this subject and concluded that repressed feelings of loss, denial, depression, inflexibility, conformity, high levels of anxiety and dissatisfaction, and many life-change events are associated with increased cancers, heart disease, and infection. ⁴

Stress is the organism's response to those external factors or stimuli that demand some reaction or change in behavior. If unrelieved stress is present early in life and of sufficient magnitude, it can lead to increased heart disease, mental illness, and suicide later in life. Dr. Girard has concluded that unrelieved stress and negative psychosocial events are positively correlated with increased illness.

Dr. George Vaillant, of Harvard University, tracing the 40-year history of 204 men, found that poor mental health was associated with increased disease and death over and above the effects of drug abuse, obesity, or family history of longevity. Dr. Vaillant concluded that "good mental health facilitates our survival." ⁵

A growing body of evidence suggests that negative life stress and a lack of social and community ties are also associated with increased disease and early death. Dr. William Ruberman recently showed that socially isolated male heart-disease patients (few contacts with friends, relatives, and church or club groups) with a high degree of negative life stress had more than four times the risk of dying from heart disease compared to men with low levels of isolation and stress. ⁶ This supports William Harvey's statement in 1628 that "every affection of the mind that is attended with either pain or pleasure, hope or fear, is the cause of an agitation whose influence extends to the heart."

Exploring the converse association, that a physically fit body would lead to a sound mind, researchers have conducted more than 1,000 studies to determine whether or not exercise really results in measurable improvement in depression, anxiety, intelligence, self-concept, and other psychological parameters.' Unfortunately, in their eagerness to prove what so many already believed, most researchers have followed poor research procedure. Only recently has strong evidence emerged.

Exercise relieves stress

Dr. James Blumenthal, of Duke University, was the first researcher to show that Type A behavior can be lessened with exercise training. ⁸ People who exhibit Type A behavior lead rushed lives, often being hostile, aggressive, and driven to prove themselves. Some studies have found that, compared with calmer, more easygoing persons, Type A's have twice the risk of suffering a heart attack by age 65, though not all research supports this concept. ⁹ Dr. Blumenthal found that middle-aged men who walked and jogged three miles three days per week for 10 weeks decreased their Type A behavior, and a recent study by Dr. Charles Lobitz, of the University of Colorado, reported similar results.

During the past 15 years a large number of studies have shown that life events of all types (getting married, getting divorced, buying a house, being fired, moving to a new home, undergoing surgery) are significant stressors, with predictable resultant physical and psychological health problems. Two recent studies have shown that such life stress has little impact on the health of physically active individuals. ¹⁰

Dr. J. H. Howard conducted a four-year longitudinal study of 278 managers from 12 corporations. The data indicates that physical activity buffered the relationship between life events and illness. ¹¹ Dr. D. L. Roth's study of 112 students showed that a high level of life stress was related to poorer subsequent physical health for subjects with a low level of physical fitness, and that students with a high level of physical fitness were buffered from the ill effects. ¹² Dr. Roth concluded that fitness moderates the stress-illness relationship, and that increasing fitness may be a way of diminishing the effects of unavoidable stress.

A team of researchers at Duke University has shown the importance of exercise on various psychological traits. ¹³ The subjects of their study were 16 middle-aged men and women matched with 16 control subjects. After 10 weeks of walking and jogging 45 minutes, three times per week, the exercising adults showed significant improvement in overall psychological function. Exercising subjects showed elevated vigor and less anxiety, depression, fatigue, and confusion. This study shows that, by exercise, even basically healthy, well-adjusted, middle-aged persons can increase their sense of well-being.

Exercise does more than decrease anxiety and depression and elevate mood. It also improves self-concept, which strongly correlates with exercise in most studies. ¹⁴ Dr. James Hilyer, of Auburn University, studied three groups of 40 college students; he divided them into a 10-week exercise group, 10-week exercise-plus-supportive-counseling group, and a control group receiving no exercise or counseling. Dr. Hilyer found that combining running with supportive counseling effectively helped persons with a low self-concept gain more positive views of themselves. ¹⁵ In another study, Dr. J. Eickhoff demonstrated that a 10-week aerobic dancing course increased self-esteem and self-concept, especially in subjects who were in the lowest fitness category to begin with. ¹⁶

Recent results also show that memory and intellectual function improve with exercise. Dr. R. W. Bowers, of Bowling Green State University, found that after 10 weeks of a walking/jogging program, formerly sedentary middle-aged individuals markedly reduced their reaction time in a mental task involving memory. ¹⁷ Other studies show that mental cognition improves during and immediately following exercise. ¹⁸

Special population groups have shown surprising responses to exercise programs. Mentally impaired and autistic children who jog show a decrease in inappropriate behavior and an increase in appropriate behavior following the exercise session." Hemodialysis patients who exercise experience less anxiety and depression. ²⁰ Clinically depressed subjects show elevated mood with aerobic activity. ²¹ Postcoronary patients decrease depression with physical activity. ²² Psychiatric patients decrease anxiety with jogging. ²³ Alcoholics on exercise programs reduce depression. ²⁴ Exercise programs have been related to improved mental performance among geriatric mental patients. ²⁵ One study showed that physically active persons over 50 had better mental health than physically passive ones. ²⁶

Thus mounting evidence backs up the Greek ideal of a "strong mind in a strong body." Regular exercise, such as walking, jogging, and swimming, is associated with better mental functioning, decreased anxiety and depression, a reduction in Type A behavior, improved self-concept and self-esteem, and an improvement in mood, increase of vigor, and decrease of fatigue.

How exercise helps

How and why exercise improves psychological fitness, however, is still a matter of speculation.

The body has an amazing hormonal system of morphinelike chemicals, called endogenous opioids, whose receptors are found in the hypothalamus and limbic systems of the brain, both associated with emotion and behavior. Endogenous opioids like beta-endorphin have been associated with decrease of pain, increase of memory, and regulation of appetite, sex drive, blood pressure, and ventilation. ²⁷

During exercise the pituitary increases the concentration of beta-endorphins in the blood. Several laboratories, including those at Loma Linda University, have measured this increase of betaendorphin. ²⁸ Some researchers now speculate that exercise of high enough intensity may open up the blood-brain barrier, allowing access of the betaendorphin from the blood into the brain, helping to decrease pain, elevate mood, and decrease feelings of fatigue. ²⁹ This may be the cause of the runner's high.

In addition, beta-endorphin appears to help decrease the normal exercise-induced rise in adrenaline and noradrenaline, which may make the exerciser feel better. ³⁰ So the elevation in mood and decrease in anxiety and depression associated with exercise might occur in part because of the influence of beta-endorphin.

Both Dr. James Wiese, of Alberta Hospital, and a research team at Arizona State University discovered that during exercise, the brain increases its emission of alpha waves. These brain waves are associated with a relaxed, meditation-like state. ³¹ The alpha waves appeared 20 minutes into a 30-minute exercise and were still measurable after the exercise was over. Researchers speculated that the increased alpha-wave power could contribute to the psychological benefits of exercise, including reductions in anxiety and depression.

Other researchers suggest that exercise decreases muscle electrical tension. ³² One new theory is that exercise may enhance neurotransmitter activity in the brain, increasing the levels of norepinephrine and serotonin in the brain and decreasing depression. ³³ Some support the idea that exercise increases oxygen transport to the brain. Whatever the real reasons for the positive effect of exercise on the brain—increase in betaendorphin, increase in the brain alphapower, or enhanced brain neurotransmission—the evidence of increased mental well-being is very compelling.

Running addiction

Dr. Morgan has described persons with running addiction. ³⁴ Such persons have so powerful a commitment to exercise that commitments to work, family, interpersonal relationships, and medical advice suffer. They also tend to be compulsive, to use running as an escape, to be overcompetitive, to live in a state of chronic fatigue, to be self-centered, and to be preoccupied with fitness, diet, and body image. Certainly this is taking exercise too far, negating any psychological benefit that more moderate exercise might bring.

One of the amazing facts to come out of all the recent research is that the same amount of exercise that helps the heart also helps the brain. The American College of Sports Medicine has established that three to five 15 to 30-minute exercise sessions per week of a hardintensity aerobic activity such as jogging, swimming, bicycling, or brisk walking is necessary to develop the heart, lungs, and blood vessel system. Most of the studies referred to in this article used these very same exercise criteria, showing that as the heart is strengthened, so is the brain.

In exercise we have a strong weapon to help counter the never-ending onslaught of stress, anxiety, and depression associated with our modem era. Exercise acts as a buffer, decreasing the strain resulting from stressful events. It fortifies the brain, helping to alleviate anxiety and depression while elevating mood.

Exercise also appears to help the brain function better intellectually. What this means for busy students and mental workers everywhere is that time spent in exercise is not lost. Instead, the half hour exercise session could mean enhanced mental functioning and thus greater efficiency. The allocation of curricular time to physical exercise does not hamper academic achievement as some school boards have thought. Including exercise breaks for normally sedentary mental workers may actually help enhance the productivity of a business.

Exercise is good for both the body and the brain. Through regular, active use of the body one can discover a greater sense of well-being and develop greater vitality and a calmer, more relaxed attitude toward daily pressures.