STARTING POSITION:
Select the appropriate weight of the bottles. Stand straight with your feet shoulder width apart with a bottle on either side of your hips. Contract your pelvic floor and core while keeping your chest up.
MOVEMENT:
Contracting your biceps, fully bend your elbows while you exhale. Extend your arms to push the bottles straight up until your elbows are extended. The palms should face forward. Slowly lower the weight until your hands are just above your shoulders. Then return to the starting position.
TIPS: The exercise key is quality over quantity. The trick is to perform the exercise using proper form.