Set-up: Begin on all fours with arms straight and both upper arms and upper legs perpendicular to your body.
Movement: Contracting your glutes, raise your working leg off the floor until your heel faces the ceiling. Pause at the top, focus on squeezing your glutes. Return to the start position under control. Movement should be generated in the hips, do not hyperextend your lower back.
Repetitions: Perform all prescribed reps on one side, then on the other. This counts as one set.