Anthony Joshua and Wladimir Klitschko in a classic battle of youth vs. experience

— -- Former heavyweight champion Wladimir Klitschko is philosophical about his 2016 in which he did not fight because twice he had his rematch with lineal champion Tyson Fury called off due to Fury's personal problems and failed drug tests.

It led to what will be a 17-month layoff for Klitschko, the longest of his decorated 21-year professional career. He has had two heavyweight world title reigns, the most recent one ending against Fury by unanimous decision in a dreadful November 2015 fight in which Klitschko looked as bad as he ever has.

But now Klitschko (64-4, 54 KOs) sounds like he has a new spring in his step as he prepares for perhaps the biggest fight of his career when he challenges young and powerful British star Anthony Joshua (18-0, 18 KOs) for his heavyweight world title on April 29 at Wembley Stadium in London, where a British-record crowd of some 90,000 is expected.

It's such an enormous fight that it could shatter British pay-per-view records on Sky Box Office and American networks Showtime, with ties to Joshua, and HBO, with a long relationship with Klitschko, which are locked in a bidding war to secure American television rights. It may be the biggest heavyweight fight since the 2002 showdown between then champion Lennox Lewis and former champ Mike Tyson.