To work on lateral glut strength in a open chain position and core stability/strength together. Great exercise for runners who need both
Demonstration and Instructions
Lie on the ground on your side resting on your forearm with your bottom knee bent, and the top leg straight. Keep your elbow directly under your shoulder. Push through your forearm and knee and drive forwards up into a side plank position with your core tight and spine straight. Hold, and start to perform hip abduction by lifting your top leg up and slightly backwards, squeezing your lateral / side glutes to perform the movement. Return to the start position and just before your leg touches the floor, repeat the exercise.