Step-ups for firming up: Try This! By Jeannine Stein, Special to the Los Angeles Times Taking a stroll? Here's a move that makes a walk in the park, well, less of a walk in a park. Jackie Warner (www.jackiewarner.com), star of Bravo's fitness reality show "Work Out" and author of the new book "10 Pounds in 10 Days," demonstrates step-ups that you can do on a bench. Why you should try it: The step-up focuses on the glute, hamstrings and quads. "It's a fantastic, full lower-body exercise," Warner says. What to do: Step up onto the bench with your right leg and pull your left knee up, to waist height, then return it to the ground. Hands clasped in front, back straight. How much: Keep going without pause for 15 repetitions. Repeat on the other side. Do three sets on each side.