Mass is just size.......I wanted pure muscle, no fat. I wanted to gain as much muscle as fast as possible.......you do this staying under 10% bodyfat year round. With that in mind, structure your training in such a way that recovery allows you to train that muscle 2-3 times a week. Training is secondary to nutrition and supplements.......but a VERY CLOSE second..........you need all 3 to be up to par to be YOUR best.
From a PURE training standpoint, do just enough to recover in time, what ever youur schedule allows. If you train once a week, you will need more sets as you do not need to recover as quickly..... and visa versa. There are many ways to structure this, but the more you can train a bodypart, the better. An example is prison workouts. These guys blow up on pushups EVERY DAY, not once a week. I used my time as an experiment and I saw many different training styles in there. The good thing was that we were all equal, NO STEROIDS. The best looking guys, biggest, leanest, worked out every day and the muscle 2-3 times a week at LEAST. Add AAS and peptides to this and the recoverability is twofold.