I've been doing further experiments using rest-pause or max-stim mixed with Matrix movements and doing bilateral comparisons. Doing a set of curls using a weight that produced around 20 reps with 5-10 sec. rest doesn't feel(not very scientific) the same as doing Matrix procedure using rest pause. I found doing a Matrix pattern of: 1/2 rep up, 2 1/2 reps down, 3 1/2 reps up finishing with 4 1/2 reps down, repeating this for 5 cycles with 10-15 sec. rests produces more inroads, more contractions(50) over a shorter period of time than conventional rep patterns. I had been trying to do 10 cycles, but that was too much. I've started doing full body workouts three days a week using squats, SLD, bench press, rowing, overhead press and supinated pulldowns. I've dropped direct arm work due to the significant effect on this area from the upper body work. The vascular effect that occurs after you finish the cycles is amazing. If one of the causes of hypertrophy is the micro-tearing that occurs during the ratcheting of muscle fibers under a load, then this procedure may be useful. This may be easier on those of us who have been lifting for over 40 years and want to use weights that are less joint challenging. I found using 80% of 1RM load difficult on old injuries after a period of time and found in the Max-Stim writings of 60% of 1RM being useful. Overfiftylifter-would like to see the moderator's view on having more contractions between rest periods.