Get in pushup position with the hands aligned with your shoulders, and the feet about hip width apart (widening the feet will create a more stable base to make it easier, and closing the width will make the exercise more challenging).

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.

Raise one foot about 6 inches, hold it up for 2-3 seconds and alternate.