Bring yourself to the ground and enter a high plank position with your hands directly under your shoulders. This is your start position. Keeping you core braced, lower your chest towards the ground by bending your elbows until your chest is just above the ground. At the same time bring one leg off the ground and bend your knee out to the side towards your elbow. Inhale as you do so. You should maintain an unbroken line from your head to yours toes throughout this lowering phase. Pause at the bottom of the movement, then press upwards from your chest and shoulders, straightening your arms and extending your leg to return to the start position. Exhale as you do so. Repeat the same sequence but bending the opposite leg up towards the elbow this time. Repeat this alternating pattern for the required number of reps (or time).