Pilates Workout - Warm-Up

Pilates Exercise- Hip Mobility Exercise 

This exercise can be conducted in sets of 4 while alternative legs between repetitions: 
Lie on your back with your legs bent and feet face-down on the floor so that you are in the preparatory position.
While breathing in, open one knee to the side and slide the foot away from you. Straighten the leg and try to keep both hips on the floor without arching your back.
While breathing out, rotate your leg inwards and withdraw the heel, while keeping your pevis anchored to the floor and your abdominals flat.
Repeat steps #2 and #3 on the other side.