Lay down on a bench with a dumbell in each hand, arms pointing straight up
Slowly lower the dumbells to your side, ensuring you keep your arms straight (your arms should be very slightly bent, avoid locking at the elbows)
Using control, return the dumbells to the very top, be careful not to lock your elbows
Repeat steps 2 and 3 until you can no longer maintain the correct technique
Tips
To get the most from this exercise, be sure not to change the angle of your elbows, your arms should stay almost straight throughout each repetition
This exercise should ALWAYS be performed under control, be sure to raise and lower them slowly, ideally 2 seconds up and another 2 seconds to come down