Once you have mastered all types of squats(as listed above), you may proceed with the single leg squat. It is pretty challenging, thus you need to be consistent and patient. To begin with this one, you first need to stand up straight. Plant your right heel slightly in front of your left foot and keep your right leg straight. Slowly bend your left knee to squat keeping your back straight, and extend your right leg slowly as you squat (as shown in the image). Stand back up, and repeat this with the other leg. Do a set of 3, consisting reps of 10 for each side.