Changing your workout every now and then is needed, it gives you a chance to do a workout that targets different muscles then the workout prior to it. It gives you a chance to align your current goals for your body, be it getting ripped where you would be engaged in more cardio than your bulking oriented workout or a workout that is more focussed at increasing specific body part such as shoulders, chest, arms (this does not mean you do not work out your other body parts) etc.
I like changing my workout plan but not too often because I like to at-least do a certain workout long enough to see if it brings about any changes in strength, muscle growth or fat burning. If you don’t give a workout enough time, you may never know its true potential, some workouts work better than others, whereas others just take more time depending on the body-part you are targeting. It is hard to see the progress in body-parts such as your legs and back in the early days, if you are working a certain body-part out most growth is not noticeable but then one day it becomes what to want it to be because all that little growth adds up.
Sometimes we become obsessed with the scale and notice that our mass has not changed and we often think the workout is not doing anything, in the early stages you may gain muscle and lose fat and some water so even though the workout is working you would not notice because you still weigh the same the last time you weighed yourself.
A couple of weeks ago I was getting bored to my old workout which was a 5 day split, and I also felt it was not best suited for my current goals so I changed it to a 3 day
compound exercise focused workout plan, one similar to the workout I used to gain my first 10kg(22lbs) before I switched to body-part per day workout.
And lastly I like changing my workout every now and then because I get bored easily, especially if I’m always doing the same workout for more than 8 weeks. I do not want my body to get used to the workouts and stop responding, I want my muscles to continue developing. Yes I can challenge my muscles using the same workouts by changing rep ranges and increasing weight but I can only do that for so long.
I like change, I like new things and experimentation but most of all I’d like to continue developing, both physically and in the acquisition of new knowledge