Lie face up, with your back flat on an exercise mat, the soles of your feet firmly on the floor and holding a dumbbell in each hand. Your arms should be extended directly above you, at a 90 degree angle to your torso, with your palms facing in towards you. This is the start position. Keeping your elbows and upper arms still, bend at the elbows and slowly lower the dumbbells towards your head. Inhale as you do this. Reverse the movement and extend your arms back to full extension. Squeeze your triceps as you do this and exhale. Repeat for the required number of reps (or time).