Not surprisingly, smoking had the greatest impact on lifespan. It substantially shortened lives.
But low aerobic capacity wasn’t far behind. The men in the group with the lowest VO2 max had a 21 percent higher risk of dying prematurely than those with middling aerobic capacity, and about a 42 percent higher risk of early death than the men who were the most fit.
Poor fitness turned out to be unhealthier even than high blood pressure or poor cholesterol profiles, the researchers found. Highly fit men with elevated blood pressure or relatively unhealthy cholesterol profiles tended to live longer than out-of-shape men with good blood pressure and cholesterol levels. (Source)