Stand up straight with a dumbbell in each hand at arm's length. Keep your elbows close to your torso and rotate the palms of your hands until they face up toward your head.
Keeping the upper arms stationary, exhale and curl the weights up while contracting your biceps. Continue to raise the weights until biceps are fully contracted and the dumbbells are at shoulder level. Hold for a brief pause as you squeeze your biceps.
Lower the dumbbells back to the starting position.