Fitness and Longevity: Cause and Effect

A classic study from the 1950s entitled “Coronary heart-disease and physical activity of work” illustrates how difficult it can be to tease out causality between physical activity and longevity. London bus drivers appeared to have twice the risk of dying from heart disease compared to bus conductors, who were presumed to be protected by their climbing up and down 500 to 700 steps a day in the famous double-deckers. However, it was later revealed in a follow-up paper “Physique of London busmen” that based on the measurements of their starting uniforms, the bus drivers started out significantly heavier. Similar issues surrounding reverse causality continue to haunt observational exercise studies to this day. Is exercising enabling good health in seniors or is good health enabling exercise in the first place? Is inactivity leading to chronic disease or is chronic disease leading to inactivity? 

Then there are the confounding factors, the ark-typal one being less smoking among active individuals. With the exception of elite male power athletes who may die at up to nearly 5 times the normal rate, perhaps due to the use of anabolic steroids, athletes tend live longer than their sedentary counterparts… —as much as 4 to 8 years longer. But think of all the complicating elements, especially among professionals. Major league baseball players… Tour de France cyclists, and champion skiers all live longer than the general population but that doesn’t mean it necessarily has anything to do with home runs, bee-sea-klates, or the slopes. Maybe it’s partly the superior genetic constitutions that allow for such physical feats in the first place, or the socioeconomic status bestowed upon the winners?

Yes, Olympic medalists live longer than the general population, but so do Grand Masters of chess, as revealed by a study subtitled “Mind versus Muscle,” suggesting it’s the afforded status rather than the muscular exertion. Winners of a Nobel Prize or an Oscar Award similarly have superior life expectancy.