Muscle Confusion: Fact or Fiction

“Muscle confusion” is a regular practice of changing things up within your workout routine, claiming to keep your muscles “confused” to illicit more results. The theory is your body never gets used to one thing, so it is constantly adapting. When our body adapts correctly, we become stronger.

The term "muscle confusion" came onto the scene in the 70’s when bodybuilding pioneer Joe Weider included it amongst his training principles. It has been re-popularized by the P90X workout series and has been on the lips of many clients and trainers alike. However, muscle confusion is more of a buzzword than it is an actual physiological principle. There are several physiological principles which are time tested, researched and approved, for which we can compare this concept to see if it holds up.

Overload Principle

The Overload Principle states that greater than normal stress or stimulus on the body is required for a training adaptation to take place. A stimulus needs to be challenging enough for the body to change. Once the body has adapted fully to the stimulus a change is required to continue improvement.

How it compares: As long as the stimulus is greater than which the body is accustomed to in muscle confusion-style training, an adaptation will occur. However, if the routine is changed drastically, then the adaptation will be short lived. A stimulus must be consistently applied, otherwise results will be lost.

Principle of Specificity

This principle states adaptation is specific to the stimulus placed on the body. In order to become better at a particular exercise or activity, training must resemble that exercise or activity. If you want to get better at running, you should run. If you want to get better at bench press, you need to do bench press.

How it compares: If the workout is changed each time in muscle confusion-style training, then it does not meet the specificity principle standards. A person doing training this way may never get better at any one thing within the training program. If muscle confusion is applied more systematically and changes of variables (sets, reps, weights, speed, slight body position changes) are slightly changed, muscle confusion can become more specific.


Periodization is an organized approach to training involving proper progressions of exercises. There is an optimal level of overload in an optimal time frame which will cause proper adaptation. If overload is increased too slowly, results will be unlikely. If they are progressed too fast, injury is likely.

How it compares: Periodization doesn’t sound as sexy as muscle confusion, but, essentially, periodization is muscle confusion done right. Periodization, takes the physiological principles into account to develop a progressive training program that applies the proper stimuli in a planned amount of time to maximize results. It also plans for plateaus and program design change.

In summary, much like any style of training, it is all how “muscle confusion” is applied. First, any training must apply a greater stimulus than what the body is accustomed to in order to get results. Second, training must progress properly so the changes that occur within training are not so drastic, but more incremental. If these two are followed, then “muscle confusion” can be quite effective. If the program is changed drastically, with no system or structure, results will be slow to come by.

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