“Muscle confusion” has been (and continues to be) one of the hottest buzzwords in the fitness industry since the early 2000s when P90X exploded the home fitness training market.
The truth is that the concept of muscle confusion is far older. It was one of Joe Weider’s 31 core training principles, aptly titledThe Weider Principles, used by golden era bodybuilders including Franku Columbo and Arnold Schwarzennegger.
While the term is carelessly thrown around these days in order to sell gimmicky fitness programs or give trainees the illusion of progress, the truth is that muscle confusion was born out of a way to help individuals shatter plateaus in their training and continue to build strength and size.
Let’s now take a deeper look at what muscle confusion is and what it isn’t.
What is Muscle Confusion?
Like most things in life, the human body has a certain set point or equilibrium that it maintains on a day to day basis. This is also referred to as homeostasis.
The body likes to be comfortable, meaning it is resistant to change.
This is why if you want to build muscle and strength, you have to make the body “uncomfortable” by engaging in progressive resistance training.
Simply performing the same exercises for the same amount of sets and reps while using the same amount of weight will work for a short time, but if you fail to change your training parameters and increase the challenge on your muscles you will plateau.
This is from where the concept of muscle confusion arose.
Fortunately for us, muscles aren’t that smart. It’s really easy to “confuse” them, and no it doesn’t involve doing 12 different variations of curls in a back and biceps workout.
You can “confuse” your muscles (and break through the plateau) by simply progressively overloading them.
This can be accomplished a multitude of ways including:
- Increasing weight on the bar
- Completed more reps
- Adding sets
- Increasing training frequency
- Slowing down the lifting tempo
- Incorporating pauses
- Doing 1.5 reps
- Reducing rest periods
- And more
Each of these provides a unique stimulus to the muscle than what it has previously experienced, which forces it to adapt and become stronger.
Now, changing the exercises that you train a given muscle group with in your workouts is another way to implement muscle confusion.
But, there are more appropriate (effective) ways to implement new exercises than constantly changing up exercises from one week to the next or doing 10 different versions of the same movement pattern in a single workout.
For instance, let’s say you are laying out a 12-week training program for your chest divided into three 4-week blocks.
Here’s an “appropriate” way to enact muscle confusion by alternating exercises.
- Flat Barbell Bench - 4x6-8
- Incline Dumbbell Bench - 4x8-10
- Cable Crossover - 4x10-15
- Incline Barbell Bench - 4x6-8
- Flat Dumbbell Bench - 4x8-10
- Pec Dec - 4x10-15
- Flat Barbell Bench - 4x6-8
- Incline Dumbbell Bench - 4x8-10
- Push Ups - 4xAMRAP
As you can see, we’ve given a range of reps to complete for each exercise and we make subtle tweaks to the exercises from one block to the next. But, you do perform a core set of exercises for each 4-week block.
The reason for this is that it takes time for the CNS to obtain movement proficiency and stability. In other words, your body needs to figure out how to perform an exercise in the most stable and efficient manner possible.
Once it has this down, you can then go about overloading it with more sets, more reps, more weight, etc.
Here is how to not implement muscle confusion from a week to week basis:
- Flat Barbell Bench - 2x6
- Incline Barbell Bench - 2x8
- Flat DB Press - 2x10-12
- Cable Crossovers - 2x15-20
- Decline Push Ups - 2xAMRAP
- Standard Push Ups - 2xAMRAP
- Incline DB Bench - 2x6
- Flat Barbell Bench - 2x8
- Chest Press Machine - 2x10-12
- Dips - 2xAMRAP
- Pec Dec - 2x15-20
- Standard Push Ups - 2xAMRAP
Sure, your muscles will be “confused” from one week to the next, but you really have no idea whether you’re progressing from one week to the next. In order to create overload, your body has to become proficient in a movement, and when that has occurred, you can then implement overload, which serves the “confusion” they need to change and adapt.
You could also keep all the exercises the same between two different training blocks, but alter the order in which you perform them.
For instance, using cable crossovers to pre-exhaust the chest before hitting your flat or incline press will feel entirely different than training presses before crossovers.
The take home here is that muscle confusion is real, and it is necessary to a certain point in your training. But, as with most things, there are better and worse ways to implement it.
Use it to drive progression and break a plateau, not as an excuse to try to be cute or make up some overly complicated workout scheme.
Now that we’ve covered muscle confusion thoroughly, let’s dive into another “muscle” buzzword -- muscle memory.
What is Muscle Memory?
Remember above when we said that muscles weren’t all that smart and they could easily be “fooled” by simply being forced to lift heavier weight or perform more reps?
Well, it turns out muscles may actually be a bit smarter than they’re given credit for.
Scientists have found evidence that muscle cells have a “memory” of sorts.
The concept of “muscle memory” has been around for decades, but only until recently did researchers find evidence of how it occurs.
The basic thrust of muscle memory is that it is easier for muscle to be regained after being lost than it is to build muscle from the ground up.
Case in point, the former high school or college athlete, who at one time was a physical specimen of size, strength, and speed. However, after their playing career they stopped training, but still ate like they did.
Their muscles would atrophy to a degree, while their waistlines expanded.
After a few years of slacking, they decide to get back to training and dieting seriously and voila!
They’re back to their “fighting weight” in a matter of months.
Contrast this to the individual who does not have an athletic background and is trying to build muscle and strength for the first time. It will take them longer to build the same amount of muscle since building new muscle is substantially more difficult and time consuming for the body than “resurrecting” it (in the case of the former athlete).
Essentially, a muscle remembers its previous size and strength levels, and it can adapt more quickly when you return to the gym following a prolonged absence.
So, how does this happen?
As you build new muscle tissue, the muscle fibers grow in size.
To grow, muscle fibers recruit satellite cells that surround the fiber and bind to it following exposure to stress and inflammation (like what happens after a hard training session).
The satellite cells donate myonuclei to muscle fibers which ultimately allows them to grow bigger.
The bigger and stronger your muscles get from weeks, months, and years of training, the more myonuclei they contain, as the myonuclei are the real drivers of how large a muscle cell can get.
The most efficient way to get muscles to grow and obtain more myonuclei is by exposing them to powerful stressors, like those found in resistance training (mechanical tension, metabolic stress, cellular swelling, and muscle damage).
This stress leads to an inflammatory process that recruits satellite cells to the muscle cell, leading to the donation of myonuclei which “prime the pump” for increased protein synthesis and muscle growth.
Now, let’s say that you suffer an injury, get sick, or just feel like taking some time away from training.
As a result of this time away from training, muscles become detrained and reduce in size.
This is perfectly normal and expected.
The reason for this is that the body always seeks homeostasis and preservation of life.
It’s not going to support metabolically demanding tissue (i.e. muscle) if it’s not being used on a regular basis.
However, while the muscle fibers may shrink, the myonuclei that were contained within that muscle cell do not go away. They remain intact and unaffected. They also remember how big they used to be.
Therefore, when you get back to training consistently, your muscles will bounce back and return to their previous size more quickly than if you were trying to build them up for the first time.
But, there’s more.
Muscle memory isn’t relegated to just your actual muscle cells. It also occurs in the neurons of your brain too.
You see, any time you learn a skill, be it squatting, deadlifting, jumping, or playing a musical instrument, regions of your brain that are responsible for that movement, such as the motor cortex, develop stronger connections between neurons that serve as the representation for a specific motion.
The more times a specific motion or activity is performed, the stronger these neuronal connections become. This is why it’s easier to come back to certain physical activities (riding a bike, for instance) and pick up basically where you left off.
Once your brain has learned a specific set of movement patterns and performs them consistently it becomes more and more proficient at carrying them out, even after a long layoff.
This is yet another reason why you shouldn’t be constantly changing up exercises each week in your workouts.
You need to give your neurons time to learn a movement pattern and then become stronger, more proficient in it.
So, as you can see, muscle memory not only occurs at the muscle cell level, but also at the brain too!
- Robert A. Seaborne, Juliette Strauss, Matthew Cocks, Sam Shepherd, Thomas D. O’Brien, Ken A. van Someren, Phillip G. Bell, Christopher Murgatroyd, James P. Morton, Claire E. Stewart, Adam P. Sharples. Human Skeletal Muscle Possesses an Epigenetic Memory of Hypertrophy. Scientific Reports, 2018; 8 (1) DOI: 10.1038/s41598-018-20287-3
- Elbert, T., Pantev, C., Wienbruch, C., Rockstroh, B., & Taub, E. (1995). Increased cortical representation of the fingers of the left hand in string players. Science (New York, N.Y.), 270(5234), 305–307. https://doi.org/10.1126/science.270.5234.305