In situations of stress, there is increased activity of the sympathetic nervous system, which leads to the “fight or flight” response. Physiologic changes include increased heart rate, blood pressure, rate of breathing, blood supply to the muscles, and dilation of the pupils. It has been proposed that frequent stressful situations may lead to negative effects on health, such as high blood pressure, raised cholesterol levels, gastrointestinal distress, or depression of the immune system.
In contrast to the stress response, relaxation is characterized by reduced sympathetic nervous system tone and increased parasympathetic activity. This may include decreased metabolism, blood pressure, oxygen consumption, and heart rate, as well as a feeling of calmness. Increased brain wave slow wave activity (measured on EEG) has been reported. Alterations in the immune system may also play a role (such as changes in cytokine activity).
It has been theorized that by learning how to self-initiate the relaxation response, negative effects of chronic stress may be counter-balanced. There are some reports that states of relaxation can be achieved after several seconds with practice. Massage, deep meditative states, mind/body interactive techniques, and certain types of music and sounds have been suggested as means of establishing a state of relaxation. Rhythmic, deep, visualized, or diaphragmatic breathing may be practiced. Mental imagery, biofeedback, desensitization, cognitive restructuring, and adaptive self-statements may also be included in techniques.
Jacobson muscle relaxation or “progressive relaxation” involves flexing specific muscles, holding that position, then relaxing the muscles. This technique often involves progressing through the muscle groups of the body one at a time, beginning with the feet, spending approximately one minute on each area. Progressive relaxation may be practiced while lying down or sitting. This approach has been suggested for psychosomatic disorders, for pain relief, to ease physical tension, to relieve “inner unrest,” to overcome psychosomatic disorders, and to relieve pain.
The Laura Mitchell approach involves reciprocal relaxation, moving one part of the body in the opposite direction from an area of tension, and then letting it go.
No formal credentialing or licensure exists for these relaxation techniques. Courses are offered at institutions including the National Institute for Clinical Applications of Behavioral Medicine (NICBM), the American Holistic Medical Association (AHMA), and the Center for Mind-Body Medicine (CMBM).