Old. Athletes often shrink from the word because arenas are primarily the land of the young. Old may be how their bodies feel but they'd rather not say. Old can be a curse and it's the easy weapon that critics use as they nudge athletes towards a retirement they're not ready for.
But old is fine with Roger Federer who wears age like his shirts. Comfortably. A reporter even asks if his win in Miami on Sunday is a neat way to say goodbye to the event and never return, insinuating a perfect ending. The Swiss doesn't take umbrage but grins. He will play till he cannot.