electric: Yeah, I use a full ROM on both movements but for different reasons. There is nothing wrong with coming a little short to keep contenuous tension either. I do this sometimes as well if I am using the movement for a pumping exercise. For explosive mass training I prefer to come out of it with dead weight and explode the weight up. Then lower it controlled and slow. For a shaping movement I want the full stretch at the lower end. This would be my approach to any explosive mass building exercise. As heavy a weight as I can control. A full ROM for a dead weight start with an explosive concentric followed by a smooth controlled excentric. Not snail slow but 1/2 tempo for explosive movements. I do not pause at the concentric peak on mass movements as the weight is normally too high to do much of a contraction anyway. The goal is to build explosive power. A bench press, squat, deadlift, military press, barbell curl, french press all fall into this category. Big lifts with a lot of weight on the bar. For shaping movements I use a moderate weight. This is your typical lifting for isolation work. I will slow the rep speed down a bit. These are normally isolation exercises with a good stretch at the bottom of the ROM. I will use 2/3 tempo or 3/4 tempo even for some lifts. So things like flys, dumbell concentration curls, tricep rope extensions, dumbell rows, latpulls, leg extrensions, leg curls etc. I treat as shaping movements. I will focus on a brief pause at the peak of the movement for these. The pause is brief enough to get a full contraction is all. I am not looking to do a static hold just a full squeeze. For peaking movements I use a lighter weight and higher reps. I would choose to use a reduced ROM to maintain contenuous tension. I do not come all the way down with the weight but will come all the way up and squeeze. I will use a variety of rep speeds for peaking movements but typically stay with a 1/2. Sometimes I go a little faster for the pump and occlusion. I really focus on a concentric peak for these. Maybe as much as 2 seconds or more depending on the feel. Each of these types of lifting have different benefits and results. It would depend upon my goal at the time. A nice mix of all three is a good way to go in my opinion. I would start with the mass work then go to a shaping movement and finish off with a peaking movement if I were using a solid split routine where I would exercise only one or two muscles per day. For full body work I stay away from peaking exercises. My goal for full body work is hyper-trophy so I would stick with mass movements and a little bit of shaping movement technique. Sorry I cant be more scientific but these are all great variations that each have there merits. You can use any of the three techniques for virtually any movement. Some just lend themselves better to each. I would keep my compound movements as mass movements or shaping movements though. Bingo to electric on his post. Use your preacher work as a shaping movement or peaking movement. Nice slow negatives with a full ROM. Save the explosive lifting for the mass building movements like the barbell curl. The hyper-extension would come from slightly too much weight or a fast descent like electric says. Since there is a break off point at the top of the preacher curl, you can implement a nice static contraction for peaking. Squeeze em good and hold it for a second or two before lowering it controlled and smooth. Remember you can use a low pulley to keep the tension over the full ROM or simply reduce the ROM to keep the tension on the muscle if you are peaking.