How Will Exercise Capacity Gain Enough Respect?

Abstract

In July 1984, Jim Fixx collapsed suddenly during a run, dying at 52 years of age of autopsy-proven coronary atherosclerosis. Fixx had popularized interest in the benefits of exercise, in part through his writings about his own self-transformation from a sedentary to a physically active life. In the wake of his sudden death, medical professionals and public followers were confused, and in some cases, dumbfounded. It can be argued that Fixx had beaten the odds by quitting smoking, losing weight, and becoming fit, thereby gaining years of life over what his genetic background foretold. Still, how was it possible that he should succumb to heart disease at a relatively young age, when, through his own hard work, he had realized the highest levels of physical fitness? Fixx and others had argued that physical activity and fitness were powerful promoters of good health and long life, and they had scientific data to back them up. Or so they thought. In one of the many newspaper articles that appeared after Fixx's death, Dr Robert Ascheim, a Cornell University cardiologist, admitted, “Does running benefit you? Nobody really has a clear answer.”1 Article see p 1377 In the 27 years since Fixx's death, scientists from many disciplines have published an enormous body of work on the physiological and metabolic effects of exercise. Higher levels of physical activity and exercise capacity are correlated with lower levels of blood pressure, heart rate, and tendency to thrombosis, and with higher levels of parasympathetic tone, cardiovascular reserve, endogenous thrombolysis, and endothelial function.2 Population-based and clinical epidemiological investigators have consistently observed a strong and inverse association between exercise capacity and adverse health outcomes.3 Scientists from the Cooper Clinic have been among the leaders in showing that men and women with greater exercise capacity have lower rates …