Lie facedown on your forearms with the elbows aligned with your shoulders, and the knees about hip-width apart.

Tilt the hips into a posterior pelvic tilt (pointing the tailbone down towards the ground). If it is no longer possible to maintain the posterior pelvic tilt before the completion of the desired time, end the set.

During the entire set, tighten the core and glutes as much as possible.