listening and learning from people who have been working out for 20 some years is great.
But realize, if you've only been doing it for a little bit, you won't have the experience to know, this doesn't work, this does and so on.
You can read and learn all you want, until you do it, you won't know.
I usually change my routine up every 10 weeks or so. Sometimes it's not that drastic of a change, sometimes it is.
Sometimes I'll go 10 weeks on one routine, do some crazy routine for 1 or 2 weeks, then take a week off, then start another routine.
it all depends on what works for you.
But if you stay with the same routine, over and over and over, year after year.
What normally happens is, your muscles won't be working as hard because its just like anything else, they become accustomed to do the same thing over and over again.
ANd many people become tired, bored, and burned out doing the same routine at the same time week after week, year after year.
Try to stick with a routine for at least 8 weeks I think. Just to see if it works and how it works on your body.
Trying something new everyweek will most likely get u frustrated because, Nothing works in a week.
Remember again, people like Ronnie Coleman not only are on insane amounts of substances, they have also been bodybuilding and working out for a very very long time. So they already know what works and doesn't work for them.
I'd recomment flipping up your routines every once in a while though, just so your body doesnt get used to the same thing and your mind doesnt turn working out into just another "task" to complete.