ive developed some good mass but im getting stuck not going up in weight at all and kinda platueing the mass also usually i just go in the gym and have somewhat of a set routine usually 6 or 5 rep range and do like 3 to 4 working sets. do about 3 to 4 exercises per primary muscle and then like 3 sets seconday muscle. anyone have some routine suggestions i need to change it up but im used to working out quite a bit so 4 days a week is pretty ez.