This is a quote from Mike Mentzer
I did notice this thing with me if I look back on it this is the only way I ever gained …anyone else noticed it?
''While you should come to expect strength increases regularly, not everyone should expect a regular, attendant increase in mass or body-weight. For the majority, strength increases precede size increases. In other words, you will get stronger for a while without getting bigger.
I don’t want to mislead anyone on this point. It is important that you understand this for reasons related to motivation. As you continue to grow stronger, however, your strength increases will eventually yield a muscle mass increase. Just how much muscle you gain, and how long it lakes, is a matter dictated by genetics.
I was just such an individual who gained weight and mass cyclically. I can remember numerous stretches during which my strength increased regularly, for up to a few months, without an accompanying size increase. Not knowing that for many, strength increases precede size increases, this was very frustrating to me. In fact, I was tempted to give up entirely more than once, but I persisted, and my burgeoning strength always finally yielded an appreciable mass increase. I have observed this same pattern with many of my personal training clients. They will gain regularly in strength for months, with little or no mass increase, and then boom! within a short period, they’ll find themselves four, five or six pounds heavier.
On the other hand, some bodybuilders experience consistent, proportional strength and mass increases. An outstanding example of this was one of my personal training clients. During a four-month period, his strength increased (he went up either in reps, weight or both) on every set of every exercise, for a total of almost 400 sets. In that time, he put on 35 pounds of bodyweight, most, if not all, in the form of lean muscle mass, as evidenced by his improved definition. This individual was all but ecstatic, as he gained more muscle in that four-month period, with his three weekly workouts averaging 17 minutes, than he had gained in the preceding four years, working out two hours a day, six days a week. (At the time I started working with this individual, he was considering giving up training entirely because he thought he didn’t have the genetics to build any more muscle!)’’