Why We Need Exercise

Physical activity is a form of tension that teaches the body how to handle stress. Regular aerobic activity raises the alarm reaction of the body and in doing so, fortifies the nerve cells by activating the production of proteins that protect cells from damage and disease. Similar to a dose of inoculation, exercise raises the body's stress threshold by building the body's resilience.

In a recent experiment done at the National Institute of Mental Health, a group of mice subjected to intense stress developed anxiety-like behavior. They froze, hid in dark corners, refused to eat and acted in a depressed way.

However, another group of mice that had been allowed access to running wheels and passageways weeks before being subjected to the same stress, did not show signs of trauma at all. They appeared to have been immunized against the intense agitation they experienced. Somehow, the exercise they had on the running wheels made them stress resistant.

In short, exercise worked like a dose of inoculation with this second group of mice, providing them with a vaccine that primed their bodies, preventing them from falling apart.