Prone Iso Abs On hands and knees, without straining your neck (I should probably be looking down in this photo), pull your bellybutton up towards your spine. Hold and release. Repeat 15 times. Alysa Bajenaru Thanks for reading! If you like this post, use the social buttons above to share it with your friends. I'm grateful for your support! Previous Post Dynamic Arm Swings Next Post Cat/Camel