If you're in the business of adding muscle mass, you know, in order to gain muscle you have to pick up weight... No kidding. But, how much weight is the question? I get asked consistently, once a week, 365 days a year how many reps I'm doing for a particular workout, and I love it. Rep ranges are very important in the pursuit of muscle gains. After all 10 reps of squats with 365 pounds elicits far better muscle building fibers that a set of 40 at 95 pounds. The point is to train for hypertrophy, pick a weight that you can only preform for 8-10 reps and go to absolute muscle failure (meaning you can't do anymore). This is a traditional style of training that has been used since Arnold Swarzenegger was in the gym. Do this and you will grow!