this is what I do. I've written down 4 workout routines for every muscle group. 2 very high intensity, high weights, low reps, and 2 that are lighter weights, higher reps (called a maintenance workout). I do 1 of the high intensity workout, followed by 1 maintance, then the other high intensity then the other maintance. Basically it's a different workout every week of the month then repeated. I got this from my ISSA seminar that had some very good research and results behind it. It's used to increase limit strength when you've hit a wall.