/lit/ - Literature

Looking for recommendations for the /fit/lit/ master race. Any books about pushing yourself to be better. Fitness books, self help, pop science, fiction where the main character has to grow and persevere, samurai bushido (fiction or non) where warrior and philosopher are one in the same.

Bonus points if somebody can hit me with the source for that quote from some philosopher saying what a pity it is for man to grow old without seeing the beauty his body is capable of.