Loop a long resistance band around a secure anchor point close to the floor. Ensuring a good distance between yourself and the anchor point come into a high plank position on the floor with the other end of the resistance band gripped firmly in one hand. Extend the arm holding the resistance band directly out in front of you. There should be a good amount of tension on the band. This is your start position. Keeping your core braced and hips still, pull the resistance band back and in towards your torso, squeezing your middle back as you do so. Maintaining control reverse the movement back to the start position. Repeat this movement for the requried number of reps (or time) on one side before changing to the other