Right Time for a Change
You've probably heard that you'll need to change up your workout routine to avoid weight loss and muscle gain plateaus. You might have also been told you need to keep your muscles guessing by changing things up every week.
But are these statements really true? The answer is both yes and no.
False: You don't need to confuse your muscles by constantly changing up your workout routine. Doing so will actually work against you, because the constant changes won't give your body the proper time to adapt.
True: You do need to make changes to your workout program in order to maximize your results. There will come a time when you hit the dreaded plateau and will need to change up your routine.
False: You don't need to make wholesale changes to your workout program. Even slight changes, including switching the order of exercises, changing your rep scheme, changing the angle of an exercise (flat bench vs. incline bench) or adding in more rest days, will all help you to avoid a plateau.
True: You can stick with the same routine for many weeks, and even months, before you need to change anything. For example, I've had clients continually progress using the same routine with only the slightest variations for as long as 6 months.
Adaptation is a slow process, and it needs a lot of consistent stimulus (exercise) to be able to make the necessary changes. For example, it takes months to build even just a few pounds of muscle. If you change your workout too frequently, there won't be a consistent stimulus and you'll lack results.
So how do you know when to change things up? I wish there was a secret formula, but there's not. It's really based on feel. The more experienced you are, the better you'll get at knowing when it's time to make a change.
One good rule of thumb is to run your program until you stop noticing progress for 3-4 weeks. At that point, you can either try making a small change or a wholesale change. It all depends on how you feel and what you want to accomplish with your workouts.