The Easy Challenge:
Basic stretches followed by 15 lunges, 15 squats and 10 toe touches.
The Advanced Challenge:
Basic stretches followed by 3 sets: 20 lunges, 10 pushups and 25 squats.
How to do lunges: http://exercise.about.com/…/lowerbodywork…/ss/howtolunge.htm
How to do squats:
http://exercise.about.com/cs/weightlifting/ht/Squat.htm
Learn proper form for static lunges without hurting the knee as well as mistakes that can cause knee pain and problems.
EXERCISE.ABOUT.COM