do endurance athletes live longer beause of voluminous exercise or because their genes predispose them to high 02 oxygen uptake in later years?

If data show that endurance athletes live longer than non endurance athletes is it  so because of the life prolonging effects of endurance exercise performed over many years or is it the case that the endurance athletes genetic inheritance allows them to not only run long and fast but to survive longer. By survive longer I mean in part that for example  an octogenarian with an 02 maX of 30 is more likely to withstand the physiological trauma of septsis or major trauma better than an age cohort with an 02 max of 19.

A person',s maximal oxygen uptake(v02Max) is a strong predictor of life  expectancy. A major part of frailty in the elderly  is a low 02 max.