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Beginning (gram on left) – Lay on your side on the ground with both knees bent and on the ground. Place one elbow down on the ground for support and reach knee up to the elbow. Keep your upper body on the ground.
Intermediate (mom in middle) – Place elbow on the ground for support, tuck in both knees to elbow, keep repeating.
Advanced (me on right) – Lift both upper body and legs to each other in pike position, crunching your side/oblique.