U2 shook a packed Olympic stadium in the northern Italian city of Turin as Bono strutted, pranced, jogged and danced with little sign of being a 50-year-old rock star just 10 weeks off spinal surgery.

"I don't really know how to hold back, is the problem. You have to let the songs sing you at a certain point," Bono told Reuters just before relaunching the second leg of U2's 360 Degree Tour, so called because fans surround a giant circular platform. U2 and Bono, who said he had done rehabilitation work for three to four hours a day, kicked off a rousing set with "Beautiful Day" and "Magnificent."

They also played two new tracks called "North Star Acoustic" and "Glastonbury." Bono thanked the cheering crowd for letters and e-mails he had received wishing him a speedy recovery.

"This band is like a family. It's a family business, U2. I am the prodigal son. I would like to thank my brothers for their patience," the leather-clad Bono told the crowd, referring to his bandmates.