Training the body to put on more muscle size is really tough business - and there is no way to get around it. If you get to see the photographs of the champion bodybuilders working out (an actual workout, not an easy "staged" photo shoot as some magazines employ) you will quickly notice one primary thing - these people look like they are in pain. And they are. It is hard work to add more muscle! For a good example of the intensity involved to add and shape the muscles of the human body, rent the movie Pumping Iron from your local video store.
Look at the process of putting on muscle mass from a conceptual basis - you are trying to take up more space here on planet earth, and that is not an easy task. If it were, everyone would be running around with a fantastic physique. But it is painful to train at the level required to build more muscle mass. Pain is the guardian of great bodies! The ability to handle pain is crucial if you want to carve out some muscle mass. This translates into intensity. You have to be willing to work out at a highly intense level to add muscular body size.
There are many differences between champion bodybuilders. They have different theories on what time to lift, how much, how often, and what to eat. But one thing that the top ten bodybuilders, the really big guys, have in common is a strong work ethic when they step into the gym. They may take it easy all day and not appear to be hardcore workers on their day off, but when they step into the gym they really get down to the heart of the matter. They enter another world - a new zone, a fourth dimension. They are all serious business when it comes to the core workout. A strong work ethic is a key factor in making noticeable changes in the body.
There is no way around it - if you want to get big you will have to work hard. You will have to use your mind as well as your body to make it i happen. In fact it is the mind that forces the body to move ahead when the going gets tough. The mind has to be willing to accept the pain that intense training produces. It also has to coax the body through those grueling workouts in order to build muscular body mass.