I see guys wanting to switch routines around every 3-4 months??? Man, it takes 10-20 years to build a physique that you really are proud of and switching around after 3 months.........UNLESS YOU ARE OVER TRAINING.........is silly. IF you are overtraining, then you should be on a DIFFERENT PROGRAM ALL TOGETHER.......train hard, heavy, recover, not overtrain, avoid injuries, compound movements.......why change? THe only thing that SHOULD CHANGE is the weights getting heavier and heavier....so do that. DOes that come with changing from bench presses to flies? From squats to extensions? No way.........dont fool yourself. IF you are stronger from not benching or squatting for a period, then you were overtraining......period.