Your whole health: exorcise your stress.

while human intellect has developed rapidly since our species first walked upright, the physiological mechanisms that maintain our survival have evolved comparatively little. Unfortunately, the body's traditional fight-or-flight response to stressful situations seldom offers the best way to deal with the problems we encounter daily in modern times. The bulk of today's stress is cognitive, not physical, in origin, yet the body is still reacting as it was millennia ago when physical attack was high on the list of concerns.

When the once widely-needed stress response overstays its welcome--as it often does these days, in which our work-related worries, for example, seem never to entirely resolve--unhealthy and often chronic stress results. The physical and emotional manifestations of the stress response, such as increased heart rate, blood pressure, blood sugar levels and muscle tension, as well as anger and anxiety, are designed to dissipate when an immediate physical threat is over. When they stay on due to the complex set of worries we now face, they can turn against the body. Our bodies cannot distinguish between life-threats and other, far more common sources of stress, from traffic jams to marital spats. Over time, the hormones causing these responses may wind up causing heart disease, hypertension, suppressed immunity, colitis, irritable bowel syndrome and even depression.

Since the fight-or-flight response is designed for physical action, regular exercise is a great way of dissipating the physical manifestations of stress hormones in the body. Exercise, even regular stretching, can relieve tension in the muscles. Furthermore, while fight-or-flight mode often taxes the immune system by readying the body for physiological warfare against an outside force, studies show that moderate physical activity can bolster the immune response.

Exercise can also counteract the anxiety adrenaline and cortisol may cause when they flood the bloodstream for prolonged periods. Most obviously, exercise is an outlet for excess adrenaline, and has been shown to blunt cortisol production. But another way it achieves this is by releasing serotonin, a neurotransmitter that stimulates the brain's "happy centers." This occurs most dramatically within the first 30 minutes of physical activity, then tapers off. Exercise also induces the release of endorphins, which block pain messages and can enhance mood. Finally, there are peripheral benefits to physical activity as well. The self-confidence that comes with weight loss and improved body image affects our outlook, and so our interactions with others, which in turn further improve our mood.

(J. Appl. Physiol., 2004, Vol. 97, No. 2, pp. 491-498; J. Psychosom. Res., 2004, Vol. 56, No. 3, pp. 363-370; Reducing the Burden of Stress, Harvard Women's Health Watch, 2003, Vol. 10, No. 1; Stress Control: Techniques for Preventing and Easing Stress, Harvard Health Publications, Palm Coast, FL, 40 pp. $16; Psychopharmacology, 2001, Vol. 155, No. 3, pp. 234-241; Acta Physiol. Scand., 2001, Vol. 173, No. 2, pp. 223-230; Neurosci. Lett., 2001, Vol. 301, No. 2, pp. 143-146; Amino Acids, 2001, Vol. 20, No. 1, pp. 35-47)