You're going to lay down on your mat, keep both legs out in front of you, out to the side. You're going to take your top leg and place it right in front of your bottom leg. This exercise is really going to target the inner thighs here. You're just going to be lifting your bottom leg up and down underneath the top leg. All you're doing is make sure your foot is flexed. You're going to take that leg up and down, up and down, just like that. This is really going to target that inner thigh area. As you press that leg up, I want you to think about squeezing the inner thigh. Bring it up as high as you can. The higher you bring the leg, the more you're going to feel that deep squeeze in that inner thigh. You're just taking that leg up and down. You want to make sure that your upper body stays stable so you're not rocking back and forth as you do the exercise. Your core is tight and engaged. You're just taking that bottom leg up and down, up and down, just like that.I usually recommend doing 10-12 reps on either side, doing 10-12 on one and then 10-12 on the other. That's how you do the Pilates side lying leg lift.