Weighted Single Leg Box Squats are a phenomenal exercise and ski workout that Heather McPhie uses to develop explosive strength and dynamic balance during the preseason. You can mimic this exercise at home to prepare for ski season. This routine requires heavy use of the glutes, quads, hamstrings, calves and core. This a great exercise for skiing because it requires eccentric strength (lengthening of the muscle while contracting) on the way down and good balance and control coming up.
On one leg, slowly lower yourself down to the box. It's important when doing this lift that your knee doesn't cave in toward the mid-line of your body. Focus on keeping your head up, chest out and pushing through your heels. Pay particular attention to pushing with your glute. Start with three sets of eight repetitions per leg for this exercise.