Remember when Rocky Balboa's cross-training in preparation for his rematch against Clubber Lang included swimming?
Well, Michael Phelps added boxing to his regimen before the 2012 Olympics in London. Time just republished this video feature that shows Phelps doing various out-of-water exercises, which includes lacing up the gloves and trying to put together some combinations.
More Michael Phelps:
-- Michael Phelps Teaches Katie Ledecky Proper Medal-Wearing Technique
-- Watch 15-Year-Old Michael Phelps Predict He'll Win Gold Medals
-- Why Did Michael Phelps Laugh During the National Anthem? Blame the Orioles