Begin seated with your legs out in front of you, knees slightly bent and feet flexed so your toes point up and your heels are on the ground. Hold a dumbbell up by your collarbone in both hands and lean back just slightly onto your tailbone, keeping your back straight as you tighten your core.
Pull your abs toward your spine and twist slowly to the right. Keep the movement smooth and controlled, initiating it from your ribs and not from your arms swinging.
Twist back to the centre and repeat on your left side.
Twist back to the centre starting position, making sure to keep your abs tight and your back straight throughout the whole movement.