Lie down on a flat bench with your upper back and portion of your head and neck resting on the bench. Hold the barbell above your upper chest line at shoulder-width apart(or less than) with your arms fully extended. This is your starting position. If you're a beginner you may need a spotter to help you get into position.
Lower the barbell down until it's past and above your head. Then, raise it back up again to the starting position.
Repeat entire movement for the desired or prescribed number of repetitions.
Perform this exercise in a smooth and fluid motion
Keep your arms straight for the duration of the entire movement
Don't arch your back too much
Don't rush the movement
SPECIAL NOTES & LEVEL of DIFFICULTY VARIATIONS
To increase the level of difficulty, slow down the movement or load the barbell with more weight.
This exercise is great for your back. Some bodybuilders swear by it in fact! However, we must point out that the execution of this movement has to be on point for the exercise to have impact on the intended group of muscles - your back (lats to be more specific).
The positioning for this exercise is very important. You have to get into the right position on the bench first. The second thing that is important is your arms. For this exercise, imagine that your arms are just part of the bar. They are straight and rigid as if they are welded onto the bar and have become one with it.
If you execute properly and perform this exercise well, you will most definitely feel some soreness in your lats the next day. That is a good thing because that will mean that you did the exercise right.