Mix-and-Match Boot-Camp Workout

Credit: Chris Fanning

Core: Ab roller

Lie on your back, with knees bent and toes on a sturdy ball (like a basketball). Tuck tailbone and pull abs in; keeping your lower back on the floor, lift shoulder blades off the floor and reach arms forward. Keep them lifted as you roll the ball forward until legs are straight; bend knees to roll the ball back in. (To make it easier, hold onto your outer thighs instead of reaching arms forward.)

Next: Core: Curl with dumbells