Murs enjoys a rip-roaring time
Olly Murs let rip when he started showing off his training tips for people signing up for a charity run.
The singer, who came second in the sixth series of the X Factor, was filming a warm-up routine to help runners doing the Sainsbury's Sport Relief Mile when he tore his trousers.
Red-faced Olly, who co-presents X Factor spin-off show The Xtra Factor, told viewers: "So when you do it make sure you're not wearing tight trousers, make sure you've got a nice pair of loose shorts on."
More than one million people are expected to take part in this year's run on Sunday March 25, which raises money for good causes around the world.
Other celebrities supporting the cause include comedian John Bishop, who is attempting to cycle, row and run 290 miles (467km) from Paris to London in five days; Ulrika Jonsson and Amy Childs, who are among the names taking part in Let's Dance For Sport Relief; and Blue Peter presenter Helen Skelton, who completed a gruelling 500-mile (805km) expedition across Antarctica last month.