Stand with your back straight, feet hips width apart and knees slightly bent.
Reach one arm forwards and the other back to shoulder height.
Keep your hips and lower body square by activating your core stability muscles, but allow your upper body and shoulders to rotate with the arms.
Turn your head to look at your back arm.
Swing your arms to change positions, rotating your upper body with the movement.
Turn your head at the same time to look at the other back arm.
Continue this movement, increasing the speed at which your swing your arms.
Make sure you hips and lower trunk remain square.
