No.

Looking at it pragmatically, being out of shape has a pretty good correlation with a reduced lifespan, and a *big* correlation with higher quality of life as you get older.

Compare that with a chance of an accident (with a car or wildlife), and it's easy to make a choice.

Looking at it more spiritually, I cycle and I downhill ski for the sheer joy of it. Giving that up really isn't an option.