Arnold Press

Stand with feet shoulder width apart, back straight, and a dumbbell in each hand with elbows bent, dumbbells in front of shoulders at chin level, and thumbs facing out.

Press dumbbells straight up in the air while simultaneously twisting the arms so that when the elbow is locked at the peak of the movement the thumbs are now facing inwards.

Reverse the twist of the arms to lower dumbbells back to the starting chin level thumbs out position.