There are many ideas and beliefs about what the best method is to follow for building the greatest muscle size (hypertrophy).
There are concepts such as every exercise must manage a prolonged muscle tension time for atleast 40 seconds or that a "secret" exercise you haven't heard of will grow a particular muscle group.
There are many questions about hypertrophy. Any method has to be established on research of muscle anatomy and mechanics. Some of these findings are:
1) The most important stimulus in all strength and muscle hypertrophy is heavy physical loading.
2) Increase in strength and size occurs during the recovery period after physical loading.
3) Not all tissue (muscle, tendons, bone etc) hypertrophy or strengthen at the same speed or to the same extent.
4) There is little increase in strength or size unless a minimal threshold is enforced.
5) The minimal threshold increases with new levels of adaptation so physical loading needs to be advanced to progress.
6) Changes in strength and size are not continuous. Some changes may be delayed.
7) Training for strength and size does not always need to result in fatigue.
8) An increase in strength is not always linked to an increase in size and vice versa.
9) Muscle tension is not fixed throughout movements but varies between zero and a specific maximum as joint angles change.
10) Strength and Size decline if physical loading is not executed within a certain time period (generally around 5-6 weeks a gradual loss will occur).
Progressive overload is far more important than time under tension.
Long periods of muscle time under tension are seen in endurance running and cycling and are not known to build large increases in strength or hypertrophy.
