Los Angeles Mar 5: Pop sensation Justin Bieber has posed shirtless for the cover of Men's Health magazine. The Canadian heartthrob who just turned 21 shows off his muscular physique for the magazine's April edition reported Ace Showbiz. In an accompanying interview the singer opens up about reinventing himself and growing up. I do aspire to be a class act. This has really been a big year for me as far as figuring stuff out. This is almost like a full 180 from how I was. Yesterday - a year from yesterday - I was in jail Bieber said. Bieber
