One of my favorite strength coaches says that you cannot stop adaptation. The body is always learning. It is always getting better at what it does the most often. If you sit in a chair all day, you will eventually become chair-shaped. If you only perform one exercise for a year, you will eventually be shaped like that exercise.
Adaptation is something that rewards us–when we reinforce good habits–or punishes us if we do things that are not optimal for our body.You are always getting better at something, even if you are getting better at getting worse.
This is in sharp contrast to what many of the bodybuilding magazines preach. In the commercial world of bigger muscles, “no pain no gain” is the law. If you want to build muscle, you have to be willing to suffer it. You must force an adaptation. If you work a muscle hard enough, it will adapt (and grow) in order to survive.
According to conventional, advertisement-based fitness magazines, muscular hypertrophy is about forcing adaptation. But if adaptation cannot be stopped, I believe that it would be possible to build muscle without forcing it. I have done it myself.
Performing a weight lifting movement is simply imposing a stress on the muscles that are used during the movement. The body literally creates new tissue along the lines of the stresses we impose on it so it can get stronger. This is true whether the effort is maximal (think of someone lifting with a purple face and veins bursting out everywhere), or minimal (think of someone lifting in a calm state).
The interesting thing is that if you always lift in a calm state without maximal exertion, you will be able to move more weight during the course of a workout. Ultimately, the volume of the poundage moved during a training session is what leads to bigger muscles, not the amount of pain endured during a lift.
I have experienced this and my results have been wonderful (for me). If you are experiencing plateaus in your quest for more muscle, I would urge you to consider trying less effort rather than more. Try lifting calm for a while and see if it jump-starts your gains. I believe it will.