There are literally only four reasons for a grown man to engage in exercise and physical training:
to further your career as a professional athlete
to prevent early death or poor health by counteracting the effects of gluttony, indolence, and addiction
to enhance your appearance because of difficulty attracting a mate
to gain the ability to suck your own dick
It must be incredibly embarrassing and unfulfilling for people who spend significant time working out yet are unable to suck their own cocks.