When you do a typical bench press rep, it's a little known fact that a good percentage of the last part of the movement (as you come to lockout) is used by the body to decelerate the bar. The lighter the weight you use, the greater this percentage is. The heavier you go, the lower this percentage is.
This is a safety mechanism used by the body to prevent joint injury. It sense the load on the muscles and joints and will actively work against the movement in order to slow down the resistance and protect the joints!
This nervous system inhibition, while useful for not wrecking your joints, will actually reduce your strength in heavier lifts. Even though the weight is heavy and basically slows itself down, your body still tries to actively work against the movement as you come to the top.
This means as you get to the lockout in a powerful bench press attempt, your body is trying to slow the bar down and you may not be able to lock it out!
There are a number of ways to train the nervous system to stop doing that...bands, chains, plymetrics, etc. But this particular method is something you can use in your warm-ups to help get your body out of the inhibition pattern.
It's basically an explosive push-up type of movement but you don't do it on the floor...you do it kneeling on the bench, and you pop up off the bench press bar.
I use it every time I do barbell bench press and find it really helps "train up" the nervous system to perform the movement more effectively.
The setup is simple - the bench with the barbell means you're already set up and ready to go!
Just kneel on the end of the bench facing the bar.
Then let yourself fall forward, catching yourself on the bar.
Let your chest come all the way down to the bar then explode up, popping yourself right back to vertical with your hands fully off the bar.
By popping off the bar, the nervous is tuned to NOT slow down. The nice thing is, it's an easy movement - you can do about 8 to 10 reps of it and get some blood into the muscles without taxing your body at all.
I find it to be a very effective warm-up for benching.