Cardiorespiratory fitness

Being physically fit is a good thing. Any number of studies have shown that it carries benefits for both cardiovascular and non-cardiovascular systems.

But can one take it too far? Is there a point where vigorous exercise leads not to better health but to stiffening of heart muscle, aortic dilation (stiffening of the major blood vessel, the aorta), and coronary artery hardening? Probably not, according to a follow-up study of more than 100,000 people who had exercise testing on a treadmill. The highest aerobic fitness was associated with the longest survival, regardless of age, sex, or other medical conditions.