Hard-wired for Exercise

Philip J. Goscienski, M.D.

May 2006

Exercise will make you more fit but that's only a small part of the story. Humans are designed for much more physical activity than most of us get and every cell of the body benefits from it. Barely 20 percent of Americans are physically active enough to enjoy those benefits. But talk about misperception! More than 80 percent of us think that we do.

Those of us who savor the soft life now will have to endure a hard life later. The human body evolved under conditions that involved lots of activity for so many thousands of years that it depends on moderate physical stress in order to function well.

If we don't stress our bones with fairly heavy lifting, carrying, pushing and throwing, those bones will become thinner. After all, why should the body maintain a strong, heavy skeleton if it doesn't need it to support a lot of muscle? Thin bones are fragile, a condition we all know as osteoporosis. That's a pretty obvious example, but there are lots of subtle ones.

Most people would be surprised to learn that there is a connection between exercise and gallbladder disease. The more you exercise, the less likely it is that you will ever have to undergo surgery to have your gallbladder removed. In a study of more than 60,000 women, those who exercised 2 or 3 hours a week had 20 percent fewer gallbladder operations than their inactive counterparts.

Calling someone a musclehead is no compliment but if you maintain your muscle mass with exercise it's a good bet that your brain will work better, too. Exercise not only improves short-term memory, it will improve your mood and protect you against depression. Persons who are physically active throughout their lives are less likely to suffer from stroke or Alzheimer's disease, so that their last decades truly become their golden years.

Ever notice that athletic individuals don't get colds as often as couch potatoes? Regular, moderate exercise powers up the immune system. That becomes a life-and-death matter in the elderly, few of whom get much exercise. It's no wonder that hospital-acquired infection is so common among the senior population. By retiring from physical activity as well as their jobs, they lower their resistance to germs that younger, fitter persons are able to overcome.

You can lower your chances of getting several forms of cancer — breast, prostate and colon — by exercising throughout life. The reasons are not yet understood, although women who accumulate fat by being inactive raise their estrogen levels, which increases the risk of breast cancer.

From middle age onward, poor sleep patterns and arthritis become annoyances that interfere with lifestyle. Both will improve with regular exercise. Persons who exercise with moderate intensity, such as walking for at least 45 minutes several times a week, fall asleep more quickly and average about one hour more of total sleep than persons who never exercise. Osteoarthritis, which affects more than half of the elderly population, is less painful and limiting among those who engage in exercise that is appropriate for their age and condition.

Philip J. Goscienski, M.D. is the author of Health Secrets of the Stone Age, Better Life Publishers 2005. Contact him at drphil@stoneagedoc.com.