I run, but boxing conditioning is different, so you have to get used to running in the ring. Boxing movements are very different. Swimming is one of the best because every single muscle is working. I swim a lot. I train very hard at things that mimic boxing. I have to do mostly sport-specific training, such as lots of sparring.

My goal is not getting hit and to knock the other guy out. Some people might complain because they want to see boxers beat up on each other, but you cannot last long in professional boxing if you take a lot of punches.

Wladimir Klitschko Quotes