Considerable evidence documents the countless benefits of a sound exercise program. Some of these benefits are obvious: an improved level of muscle tone, a leaner body, a radiant glow that often occurs when individuals feel a sense of accomplishment, etc. Many of the positive consequences of regular exercise, however, are not outwardly apparent. When considering the mind/body connection, there is definitely "more than meets the eye" for the benefits of exercise.

Physical activity has been shown to affect a person's mental and emotional processes, both during and after exercise. While the degree to which these processes are influenced varies with the individual, type of exercise modality and specific features of the program (how long, how hard, how often), exercise can have a meaningful impact on the various facets of the mind/body connection. The many benefits attributed to exercise include the following:

• May enable a person to think more clearly
• May improve short-term memory
• May relieve stress
• May influence a person's mood state
• May decrease depression
• May enhance a person's level of self-esteem
• May influence addictive behavior
• May promote brain-cell growth
• May increase creativity

Clearing mental clutter

Research indicates that regular exercise enhances an individual's ability to think clearly and to perform certain cognitive tasks. How exercise influences these factors is not known. One plausible theory is that exercise increases body temperature, which speeds catalytic occurrences that facilitate cognitive functioning and performance.

Exercise can improve short-term memory by energizing and revitalizing the mind. The reason for this may be simply because exercise increases the flow of both blood and oxygen to the brain. This benefit may be especially consequential for older adults, who can have memory problems with advanced age.

Coping with the demands of life

Data on physical activity indicate that individuals have reduced levels of stress as a result of exercise. Regular exercise can reduce stress response and boost a person's ability to recover from stress. There are several theories to explain why stress reactivity diminishes following exercise. The "opponent process theory" hypothesizes that the physical stress of exercise may elicit an opposing response (reduced stress) after exercise. Another theory, the "sympathetic toughness concept," suggests that repeated exposure to physical stress may train the body to be less affected by demands on it, and to recover more quickly from psychological stress.

Brightening up

Individuals who exercise often report that they "feel better" after working out. This may result from several factors, including physiological responses (increased energy), perceptual responses (enhanced self-esteem) and affective responses (reduced level of negative thoughts and feelings). Whatever the combination of factors, it seems clear that exercise has a positive influence on the level of anxiety and general mood. To explain the effect of exercise on anxiety and mood, several theories have been advanced. One popular theory hypothesizes that exercise triggers the release of mood-altering chemicals, such as endorphins and serotonin, in the brain. Another theory suggests that simply taking a break from the daily routine can reduce anxiety and improve mood.

Improving mental health

Recent studies show that exercise can have a significant effect on depression. Sedentary men and women are more than twice as likely to be depressed as physically active people. In reducing depression, exercise has been found to be effective for all ages, for men and women, and for varying degrees of depression. But the reason for the antidepressant effect of exercise has not yet been identified.

Feeling good about yourself

Exercising on a regular basis is associated with improved self-esteem. The data suggest that physical self-esteem may encompass different factors, including perceptions of sport competence, bodily attractiveness, muscular fitness and development, and baseline physical conditioning. Thus, the impact of exercise on self-esteem depends on which factors an individual feels are important, and on the perceived impact of their exercise. The more importance a person places on the physical component of self-esteem, the greater the degree that exercise can influence their level of self-esteem. Unfortunately, attempts to research the precise cause-and-effect relationship between exercise and self-esteem have produced inconclusive findings.

Changing addictive behavior

Although a limited number of studies have attempted to identify the psychological changes produced by regular exercise in individuals with addictions, there are some promising findings. Significant decreases in anxiety and baseline depression levels, as well as enhanced levels of self-esteem, have been found in addictive individuals who exercise regularly. Positive changes in dysfunctional behavior patterns have also been reported. Although no explanation exists for the possible positive influence of exercise on addictive behavior, exercise does offer hope as an effective intervention for some individuals who suffer from addiction.

Stimulating brain-cell growth

Recent studies involving animal experiments have found that regular exercise may spur the growth of new brain cells responsible for learning and memory. In addition, the findings show that exercise can measurably prolong the survival of existing brain cells. Although the research only involved animals, the results have obvious implications for humans. If vigorous exercise stimulates brain-cell production in people, all forms of exercise can offer individuals viable tools for revitalizing their minds.

Getting the creative juices flowing

Engaging in physical activity on a regular basis may increase a person's level of creativity. Some researchers suggest that the heightened level of creativity is simply a byproduct of increased oxygen flow to the brain. Others suggest that enhanced mood and creativity result from the release of hormones in the brain that are triggered by exercise. Still others hypothesize that exercise suppresses activity in the left hemisphere of the brain (responsible for logical thought), and stimulates activity in the right hemisphere (the part of the brain that regulates intuition and creativity).

A state of mind

As exercise psychologists continue to learn more about the mind/body relationship of exercise, the behavioral consequences of regular exercise will become more well-known and appreciated. In the future, health/fitness professionals may be asked to develop detailed exercise prescriptions to address specific psychological objectives, in addition to particular physiological goals. The mind does, and will continue to, matter in exercise.