The chair squat is a very basic exercise that is useful for almost anyone. It is also important that you are able to do a proper chair squat before progressing to any of the more advanced ski conditioning exercises that will be shown in the upcoming weeks (including the tuck jump and the lateral jump progression).
A chair squat is the name of an exercise that we all do each day: the act of sitting. With the chair squat, however, you lower yourself so that your bottom just barely touches the chair, and then you stand back up with control.
Correct performance of this exercise involves the knees tracking directly over the feet. There should be no inwards movement, and the knees should not go in front of the toes. Your back should remain neutral, with your stomach muscles engaged slightly.
If you get good at this, you can progress it to a one-legged chair squat. This is similar to the single leg squat that we featured on the blog a few weeks ago http://ascentpt.wordpress.com/2013/10/23/exercise-of-the-week-single-leg-squat/
You will feel this primarily in the front of your thighs (quadriceps) and the butt muscles (glutes). Once you can do this for 2 sets 12-15 times with correct form, you can progress to the tuck jump and lateral jump progression that will be shown over the next couple weeks.