In a commentary published in The Journal of Physiology, Dr. Michael Joyner -- a physiologist at the Mayo Clinic in Rochester, Minn. -- wrote that physical inactivity affects the health not only of many obese patients, but also people of normal weight, such as workers with desk jobs, patients immobilized for long periods after injuries or surgery, and women on extended bed rest during pregnancies.
Joyner said prolonged lack of exercise can cause the body to become deconditioned, with wide-ranging structural and metabolic changes. The heart rate may rise excessively during physical activity, bones and muscles atrophy, physical endurance wane and blood volume decline.
"I would argue that physical inactivity is the root cause of many of the common problems that we have," Joyner wrote. "If we were to medicalize it, we could then develop a way, just like we've done for addiction, cigarettes and other things, to give people treatments, and lifelong treatments, that focus on behavioral modifications and physical activity."
Several chronic medical conditions are associated with poor capacity to exercise, including fibromyalgia, chronic fatigue syndrome and postural orthostatic tachycardia syndrome -- better known as POTS, a syndrome marked by an excessive heart rate and flu-like symptoms when standing or a given level of exercise, Joyner said.
His commentary is published this month in The Journal of Physiology (http://jp.physoc.org/).