In this video, Michael Phelps looks like he's ready to rip this guy apart. Chad le Clos is a South African swimmer and is apparently either doing one of two things:

  1. Messing with Michael Phelps, trying to get into his head.
  2. Just a tool, who, for some reason decided that shadow boxing has anything to do with swimming.

My guess? A little bit of both, probably.

Later on, when Phelps was asked about the warmup routine, he played it off, and remained a consummate professional.

"Hey guys, let's avoid drama, and focus on the fact that I'm the best swimmer in the world. By far."