What is the pause. The pause is your bodies ability to hold weight. I first ran into the pause while working out with a professional arm wrestler. He worked in 30 second pauses into his routines. How do you do the pause. Well lets call this guy Fred. Fred would do 10 reps on the curl bar then hold the bar half rep for 30 seconds, then repeat the cycle until failure. Fred rotated between heavy and light weight days. On a heavy day he would do 5 sets on light days he would do 3 sets. This seemed a little strange to me at until I tried it. Light day less sets - Heavy day more?? With the light day you get a lot more reps and the pause make it a real work out. On the heavy day you may only get one set of 10 reps and 1 pause. On the last set you may not be able to do the pause.
He explained benefits of the pause. Fred said there was 3 distinct things the pause would do. 1. Improve your muscles ability to hold. 2. Improve your muscles recovery time. You are not stopping after the pause, you continue with more reps. 3. Builds your mental toughness and let you know the real limit to your muscles.
I didn't pay much attention to the pause until I started doing submission wrestling. In the gym one day (after about a year of SW) I remembered the pause Fred used to do. A few months later

The pause really works! I do it a little different the Fred did. I will maybe do a few less reps and longer hold times. I try to mix it up. You want to throw new stuff at your muscles. When you first start doing this you may be surprised by the muscle burn during the pause. It can be painful. I think Fred's number 3. "real limit to you muscles" is a very important thing. When you think that you are about done, your really probably have way there:) When you are in the clinch or on the mat and get the same feeling, you will know you still have much more left. I use it with triceps, quads, hamstrings(got to be careful with these) and biceps.