Start with dumbbells held in front of you, elbows in tight to your waist and palms facing your shoulders as though you’ve just finished a bicep curl.
Without letting the elbows flare out, push the dumbbells up overhead while rotating your wrists until your palms face away from you, so the dumbbells corkscrew upwards.
Straighten your arms, pause, then reverse the movement, ready to repeat.