Whenever I do a few sets of 12 reps on any given weightlifting exercise with each rep being having a 2 sec. concentric phase and a 2 sec. eccentric phase (with no lockout and no pause at the botttom either), the most that I can lift is only about 42% of my 1 rep maximum on any given exercise. I know that that percentage of my 1RM is not the minimum percentage for optimal muscular hypertrophy and that the minimum percentage of one 1RM for muscular hypertrophy is 70%.
So, as of two weeks ago I decided to change my tempo to 1 sec. concentric, 1 sec. eccentric (with no lockout and no pause at the bottom) so that I could work with heavier weight while still doing a few sets of 12-14 reps for each exercise. However, I have realized that doing it that way would make the total TUT be about 24 sec. for each set. I've read that in order to maximize muscular hypertrophy, the TUT for each set is supposed to be 45-60 sec. for each set.
If I am not able to increase the TUT for weight that is significantly heavier than about 42% of my 1RM then what should I do in order to maximize my muscular hypertrophy gains?