Monkey D. Garp is not above boasting — it seems to run in the family — so take this with a grain of salt, but the vice admiral once claimed he crushed eight mountains as part of his training regimen to fight a mighty pirate. Yes, as in those gigantic piles of welded rock that can scale upwards of 29,000 feet high and weigh near-immeasurable tons. Is he fibbing, maybe just a little? Who's to say? What is known is that Garp the Fist can easily crumble brick, metal, and bone with his punches. Now, we've already established that Garp works hard for the strength he possesses, but it would be more than a little fib if we forgot to mention his mastery of Haki.
Haki is best explained as the art of channeling spirit energy into one of three aspects — mind control, a defensive and offensive aura, and a warrior's sixth sense. It's more complicated than that, but functionally, Garp can give you any order and know that you will obey it, increase his strength and durability, and read his opponents' internal stat sheet if he so chooses. And yet, he most often doesn't because he likes relying on his physical skills. It may seem strange, but it makes sense for a man who turns down promotions so he can stay where he feels the most control. That framework helps contextualize his "One Piece" Season 1 ending, where he easily defeats his grandson but permits him to continue a life of piracy simply because he believes in himself.
