This plyometric movement can take some practice to master, but is sure to recruit all of the major leg muscles and is great cardio. Keep the front knee in line with the ankle. Try not to let your knee jut in front of the ankle or too much to either side. Put your weight into the front heel to propel yourself upward, then switch legs in the air and land gently. It's not necessary for the back knee to touch the ground as you lunge.