Side Double Oblique Crunch
Lie on your right side with your right arm extended straight above your head. Put your left arm behind your left ear. Keeping your ankles together, raise your legs off the ground, and crunch your legs and core into each other, keeping your right hand on the ground. You should be balanced on your hip/glute. Slowly return to start but don’t let your feet touch the ground. Repeat to muscle failure on both sides.