Long-lasting effects of exercise

Philip J. Goscienski, M.D.

November 2010

For decades, runners have described a feeling of euphoria known as "runner's high." Some considered this to be an elitist athletes' myth, but no longer. Modern imaging technology has revealed that specific areas of the brain that regulate mood appear to respond for several hours to chemicals that are released during intense exercise.

Persons who engage in regular but less intense physical activity also experience a feeling of well-being, but this usually occurs after two or three weeks. It may be due to improved muscle tone, enhanced blood flow to all organs and the sense of well-being that follows the successful adoption of a new healthy habit. As fat melts away and muscles increase in size and strength it becomes easier to keep up the exercise routine. Older individuals especially appreciate the improved appetite and sleep pattern.

Some benefits of exercise can last for years. Australian researchers found that those at high risk of type 2 diabetes were able to lower their risk of developing the disease by as much as 59 percent. Similar results were obtained by pre-diabetic persons in the U.S. who engaged in 3 to 4 hours of brisk walking every week. Among the exercisers from down under, the incidence of type 2 diabetes continued to be depressed for many years, even after they had drifted away from their earlier healthy lifestyle.

Perhaps the longest-lasting benefits of exercise affect the bones. Humans have only a limited period during which they can develop a fully mature skeleton. This bone-building window lasts from about the time they enter kindergarten to their graduation from college. If they fail to take advantage of that interval they will arrive at early middle age with less than optimal bone density. After the mid-twenties it's possible to maintain bone mass with regular, moderately intense physical activity but no amount of calcium from mid-life onward can substitute for energetic sports and games during the K-through-college window. Entering the thirties, the typically sedentary adult will not preserve his or her bone mass and is likely to develop osteoporosis, a condition that has already reached epidemic proportions.

The ultimate in long-term benefits of exercise occurs in pregnancy. The woman who is active in childhood, adolescence and young adulthood and therefore maintains normal body weight and skeletal development will help her child to avoid obesity, heart disease, type 2 diabetes, early-onset kidney disease and osteoporosis. What a jackpot!

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.