Lay on your back holding onto something heavy and stable. Slowly lift your legs off the floor, keeping your lower back into the floor as actively as you can. Pull your butt and back off the floor at the same time (as best you can). Think of keeping your lower back flat. Pull yourself up into a shoulder stand position, legs and hips vertically pointing. Fold back down trying to touch your butt to the floor before your lower/mid back, keeping the same slow speed and control.

Shoulders, Core - Abdominals

Miscellaneous