Instructions
Sit on a flat bench holding a dumbbell in each hand with an underhand grip.
Keep your back straight and shoulders back.
Keep your arms fully extended with your elbows close to your sides.
Rotate your palms so that they are facing in towards you. This is the start position.
Keeping your upper arms upper arm stationary, start to curl the dumbbells upwards in a smooth arc.
As you curl the dumbbells upwards rotate your wrists, so that your palms face in towards you at the end of the movement.
Continue the movement until the dumbbells are at shoulder level and your biceps are fully contracted.
Hold for a count of one as you squeeze your biceps.
return to the start position, rotating your wrists back to an underhand grip position.
Repeat.