STARTING POSITION:
Place a flat bench in front of you. Lie on the floor face down and place your hands on the bench slightly wider than shoulder width apart while holding your torso up at arms length. Support your weight on your toes and hands. Keep the shoulders far from the ears retracting your shoulder blades. Contract your pelvic floor and core while keep your body straight. Put your right hand behind your back.
MOVEMENT:
Start lowering yourself by bending your left elbow until your chest almost touches the bench while you inhale. Press your upper body back to the starting position strengthening you body while you exhale. Make sure your shoulder blades are always retracted. Repeat the movement for the specified amount of repetitions and then switch sides and repeat with the other arm.
TIPS: The exercise key is quality over quantity. The trick is to perform the exercise using proper form.