Olympic Skier Lindsey Vonn's Lower-Body Workout

Hamstring Curl

Targets: Butt and hamstrings

-- Lie faceup on ground with arms slightly out to sides, knees bent and calves resting on center of stability ball, feet flexed.

-- Lift hips off ground and bend knees to bring stability ball toward you.

-- Keeping hips lifted throughout, extend legs to roll ball back to start and repeat curl.

-- Do 3 sets of 12 to 15 reps.