Muscle Confusion Isn't A Real Thing (Kinda)

Can muscles be confused?

Let’s look at the Merriam-Webster definition of the word confusing.

  • archaic :  to bring to ruin
  • to make embarrassed,  to disturb in mind or purpose
  • to make indistinct: <stop confusing the issue> b:  to mix indiscriminately, to fail to differentiate from an often similar or related other <confuse money with comfort>

Hm, well, muscles can’t be made embarrassed or indistinct. They cannot be disturbed in mind (they don’t have a mind), or mixed indiscriminately. They do not fail to differentiate from an often similar or related other.

You get the point.

No, muscle confusion isn’t a real thing, at least not in the way people say it is.

“Wait wait. You said ‘the way people say it is.’ What does that mean?”

You might have noticed, or heard other people say, that whenever you change up your workouts, you get stronger quickly. You might even notice that you get super sore like when you first started lifting.

There’s a reason that people see quicker progress when changing up their workouts, but it ain’t because their muscles get confused. It’s because their nervous system is freaking out.

“Why would someone’s nervous system freak out because they changed up an exercise or two?”

Because the nervous system is highly adaptive. Remember when you first started driving? You had to think before every move you made. A couple of months down the road and you’re using your turn signal without thinking twice. You don’t have to think because your nervous system has adapted to the act of driving a car.

The same thing happens when you start doing a new exercise. Your nervous system doesn’t know how to handle the stress, so it freaks out.

When exposed to a new stress, the nervous system freaks out, and then quickly adapts to make sure that new stress doesn’t get you killed. As your nervous system adjusts, you get “stronger.”

“Why’d you put ‘stronger’ in quotation marks?”

Because you’re not REALLY getting stronger, you’re only adapting to the movement. In other words, your nervous system is becoming better at performing that particular exercise, and so, of course, you can lift more weight.

But, varying your workouts IS important.

Changing up your exercises every workout is a good way to stay a beginner forever.

The REAL Way To Use Exercise Variety To Keep Building Muscle

Yes, you should change up the exercise, but only under certain time constraints. If you’re a complete newb (0-6 months), then hangs the exercises after a minimum of 10 weeks. If you’re a somewhat newb (6-18 months), wait eight weeks to change the exercise.

“Why 8-10 weeks?”

Some studies demonstrate that it takes about 8-10 weeks for neurological adaptation to occur for a beginner weightlifter. Once your nervous system has adapted to the exercise, you can safely assume that you getting stronger at that movement is the result of muscle growth.

But there’s one more thing you HAVE to keep in mind. All the circumstances around the exercise MUST BE THE SAME for you to assume that your muscles got bigger. If the circumstances are different, it’s very likely that the change is what made the difference in your strength.

For example, let’s say the night before you bench press you got 5 hours of sleep instead of the 8 hours that you got the last time you bench pressed. See where I’m going with this?

There are quite a few cases in which something can throw off your strength.

Here’s a list of examples,

  • Amount of sleep.
  • Amount of food before lifting.
  • Warm-up (or lack thereof).
  • The weights you use (if you use different plates then they may be heavier or lighter than the plates you used before).
  • Form improvement (or break down).

Here’s How to Use Rep Ranges to “Confuse” Your Muscles

If you decide not to change the exercise after ten weeks, changing the rep range is a good option.

After ten weeks of doing an exercise within a certain rep range just modify the rep range.

For example, let’s say you were doing sets of 8-12 reps on the bench press. After ten weeks, change the rep range to 4-8 or 1-5.

Then, work within that rep range for another 8-10 weeks.

“Why does changing rep ranges help spur new muscle growth?”

First of all,

Strength guys and bodybuilders like to act like muscle size and strength are entirely different, but they ain’t. Across research, strength and muscle size are HIGHLY CORRELATED.

Two things increase strength, neurological adaptation, and muscle size, period.


Your muscles have a fixture of fiber types. There are a few fiber types, but the main two you need to know are FAST and SLOW twitch fibers.

These two categories of fibers fatigue in different ways (keep in mind that muscle fibers must be fatigued for them to grow).

Fast twitch fatigue requires quick, explosive movements (like sprints or high amounts of weight for low reps). Slow twitch fatigue requires long non-explosive movements (like running a mile or lifting light weights for high amounts of reps).

So changing the amount of weight, and the number of reps will change which fibers you’re recruiting, and which parts of the muscle you’re training.

Click here to check out a study that discovered evidence that suggests that an exercise only stimulates parts of a muscle.

So, yeah, changing the load absolutely counts as “muscle confusion.”

Here’s what you need to know in a nutshell,

  • Change the exercises you are doing after a minimum of 10 weeks if you are completely new to the gym (0-6 months) or relatively new (6-18 months) in order to optimize muscle building.
  • If you don’t change the exercises, change the rep ranges after about 10 weeks.


  • Kenney, W. Larry; Wilmore, Jack; Costill, David (2011-11-18). Physiology of Sport and Exercise, Fifth Edition. Human Kinetics. Kindle Edition.
For BeginnersWilfredo Thomas