Sometimes I like to utilize paused reps for certain exercises because it keeps the muscle being trained under tension for a long period of time which is great for muscle gain, and by pausing you will not be allowed to use momentum which is great. How does a paused rep work? Lets say you are doing a flat bench press, when you get the weight to your chest you will pause for 2-3 seconds and then eplosively press the weight back to starting position. Be sure to lower the weight in a controlled manner for at least 2 seconds. Pause for 2 seconds and press. When you first start doing these you will probably have to lighten the weight just a tad, but building muscle isn't about the amount of weight. Its about the amount of stress on the muscle. The greater the stress the more growth you can expect. You will notice not only muscle gain from this, but also strength gains. My favorite exercises to do paused reps with:
Chest: The flat barbell bench press.
Back: Pull-ups. Pause for 1-2 seconds at the top, go all the way down and pause for an additional 1-2 seconds.
Quads: Leg presses. Simply pause for 2 seconds when your knees are at your chest. Lower the weight for 2 seconds.
Hamstrings: Seated leg curls. Simply pause at the bottom and hold the contraction for 2 seconds. Let the weight up slowly and pause at the top for 2 more seconds.
Biceps: Concentration dumbbell curls. Simply pause at the bottom for 2 seconds, and hold the contraction at the top for 2 seconds. Lower the dumbbell for 2 seconds as well.
Triceps: Over head dumbbell or barbell extension. Simply pause at the bottom for 2 seconds, hold the contraction at the top for 2 seconds, lower the bar/dumbbell for 2 seconds.
Delts: The barbell or dumbbell shoulder press: Simply pause at the top of your upper chest for 2 seconds, hold the contraction at the top without locking out your elbows for 2 seconds, and lower the bar for 2 seconds.
Traps: EZ bar upright rows with inside grip: Simply pause the bar just above the chest for 2 seconds, lower the bar for 2 seconds, and hold the bar at starting position for 2 seconds. This is basically a 2-2-2 tempo, but the difference is you must pause. Give pasued reps a shot. They will be an ego buster at first, but I'm positive as long as you're eating correctly you will make gains by doing this!