This week’s exercise gives the traditional ballet moves, the plié and relevé, a cardio-toning fitness twist. Tacking on a shoulder press with light dumbbells adds resistance to the entire exercise while also engaging more muscles, two simple tweaks that help you burn more calories in less time. “Women tend to have weak inner thighs and let their knees get lazy, caving towards the center,” explains Prevention’s fitness expert Chris Freytag. Ensure proper form—and ward off knee pain—by making sure your knees track over your toes, and thinking about pressing your thighs to wall behind you during the squat. “It’s a simple way to make sure the knees stay in proper alignment.” And don’t forget about your abs! Keeping your core engaged throughout the exercise is a belly-toning bonus that also protects your lower back. “Just keep thinking ‘abs-thighs-abs-thighs’ throughout,” Freytag says. Watch the video to learn how to do the Plié Squat and Shoulder Press with perfect form! (For dance moves, check out our 25-Day Ballet Boot Camp Challenge.)