ok, i'm getting conflicting info about when to quit on a set. lets take a set of bench presses and i will walk though my set. i keep hearing the only growth is the last couple sets where you put all the strain on the muscle. then ive heard you need to quit two sets before failure. so i grab the 75 lbs dumbells and lay down on the bench with the target range of 10 in my mind. 1...2...3...4....5.... slowing down....6 still comes up easy....slowing a little more and with 87 i can feel the muscle start to burn. 8 has started to slow down and a lot of effort goes into getting it up. 9 his a strain and barely travels up...but goes all the way to the top and the elbows lock out...barley made it. 10 goes 1/4 the way up, then the real struggle begins...half up...half way there...up a little higher to 5/8 and thats as far as she goes...i struggle with everything i have, but the wall is hit. the weights come back down and for shits and giggles, i squeeze out a couple partial reps...maybe 1/6 of the move...just to send the muscles a message. is this to far to take a set? i usually do 3-5 sets per body part of one exercise per training session. i try to push each set to this level of intensity. should i stop at 8...or perhaps the 9th rep as described above?