From Zac Efron to Mario Lopez, see these sexy stars take their shirts off
"I don't have a strict thing that I do every time. I just get a little cardio in, do a little weights," the 90210 actor (in L.A. in September 2010) tells Us Weekly. "Lately, I've been jumping rope. That works so well."
Credit: Kevin Perkins/PacificCoastNews.com