Quote[/b] ]Now, you want to know how many sets you have to use to grow your muscles. If you understood the principles as outlined above you would already know the answer to that question. If you want research on the matter, mechanical-overload studies show that a muscle can be loaded for days to weeks without being unloaded and experience tremendous growth. So ask yourself, will any number of sets you could possibly do in one workout equal even 1 hour of constant load? So asking whether you should do 1 set or 2 sets isn’t really relevant unless you are simply interested in how to set up your routine. As far as muscle growth goes, the more time under tension the more potent the growth stimulus. Once again, if you understand the principles of hypertrophy, you should be thinking, “My CNS could never handle loading the muscle for even 30 minutes in one session and still allow me to train again in 48 hours.” So, you must find the amount of volume you can handle and still train effectively in 48 hours. For someone who isn’t conditioned, 1 - 2 sets per exercise (~3-6 sets/week) is sufficient to cause muscle growth. If you have been training for many years (5+) consistently then it might take more time under tension. This person will either need to take more time training in order to accommodate more sets per exercise, or split up their workout into two sessions and train either twice per day, or 6 days per week. This is how guys like myself, Blade, Boris, and others train. I have been training for over 25 years, and it takes a bit more strain and time to overcome years of RBE. Does this mean that the principles of load and time under load have changed for me, as opposed to the new guy? Absolutely NOT!