Balance and Stretching

Chair Pose
Standing with your feet shoulder-width apart, raise your arms until they're straight out in frount of you at shoulder height. Without lifting your shoulders toward your neck, point your tailbone to the back of the room, arch your lower back and lift your chest as you slowly bend your knees as if your were about to sit on a chair. While you hold this pose, shift your weight to your heels, lifting your toes up. Hold for 10-20 breaths, then rise back to a standing position. Repeat.
This exercise builds strong quads since it works your muscles the way skiing does.
Leg Extension
Standing upright with quads and abs tightened, feet parallel and shoulder-width apart, shift your weight to your left foot. Bend your right knee and clasp underneath your right arch with your right hand. Stand up straight and keep your right hand clasped around your foot. Extend your left arm out at shoulder level for balance. If you're balanced, kick your right heel to the side and straighten your leg as much as possible. Try to hold it just above hip level. Support the pose by contracting your left buttock and abs, making your standing leg firm and your back straight. Hold for 10 breaths, then lower the leg and repeat for the other side. This pose gives your core, abs and lower back, a strength workout and sharpens your balance skills.