10 Celebrities Who Do CrossFit: Feel the Burn! (PHOTOS)

“I love it! It’s like boot camp,” American Idol alum Kelly Clarkson gushes to SELF magazine (via People). “You never work out more than 35 minutes, but it’s so intense. [...] It makes me feel like G.I. Jane. It's very empowering. I feel like I can whup ass!”