I'd characterize it as, there are things that can make you stronger that people don't want to do, e.g. fasting, undergoing stress, temperature variation, intens

I'd characterize it as, there are things that can make you stronger that people don't want to do, e.g. fasting, undergoing stress, temperature variation, intensive exercise. There are things that make you stronger that people already like to do (eating food, moving, etc), but we haven't made the effort as a society to automate those things out of our lives.