"Forever" - Chris Brown
"Love the Way You Lie" - Eminem, feat. Rihanna
"Jump Around" - House of Pain
"Smells Like Teen Spirit" - Nirvana
"Whoomp! (There It Is)" - Tag Team
The most surprising tune Chelsie works out to?
"Slow Dancing in a Burning Room" - John Mayer
"I actually like doing the elliptical to sad music," she says. "I can connect with the story and choreograph a dance to it in my head."
Originally published in FITNESS magazine, September 2010.