Olympic athletes, however, have a longer than average life expectancy.
We have to very careful with correlation/causation here. Olympic athletes are a select group of people who won the genetic lottery by certain measures. It might well be that their apparent longevity is a pure selection bias.
On genetic grounds, at least, I might actually expect a bias in the opposite direction. The "genetic lottery" as you put it works on specific traits; there's no general qualityOfPerson attribute (though see below). We might expect a few of those traits (like those relating to cardiovascular resilience, say) to contribute both to athleticism and longevity, but I'd expect some to involve tradeoffs between the two: we could imagine a trait that improved metabolic efficiency at the cost of adding oxidative stress, for example, or one that made musc...
The question is - am I doing enough exercise?
I intend to provide a worked example for you to work alongside with your own calculations and decide if you should increase or decrease your exercise.
The benefits of physical activity are various and this calculation can be done for one or all of them; some of them include: