Huh. Well let's assume causality points in only one direction, genetics->tissue->ability, then I'm screwed and there's nothing I can do about it. Let's assume that it at least points partially in the other direction, ability->tissue, now I can keep my tissue healthy by exercising.
Since I don't know for sure which direction causality points, I'm going to take the path of maximal self-determinism and try to stay fit as long as possible.
Since I don't know for sure which direction causality points, I'm going to take the path of maximal self-determinism and try to stay fit as long as possible.