an exceptionally masculine and muscular man. A compliment used in the gay community to refer to a man. It is not used lightly, usually for unusually sexy and muscular men. A mix of beefy (perhaps how the term was created), masculine, and sexy.
Wow. That man is on the hoof.
Some would say Thomas Jane in Punisher, or Hugh Jackman in X-men 3 were "on the hoof".