Come into an all fours position on an exercise mat with your hands directly under your shoulders and your knees directly under your hips. Hold one end of a long resistance band in place with both hands whilst placing the other end round the sole of your left foot. Brace your core and maintain a flat back as you kick your leg back and up, squeezing your glutes as you do so and exhaling. Slowly return your leg to the starting position, inhaling as you do so. Repeat all the required reps on one leg before changing to the other.