Is “Muscle Confusion” Better For Strength and Hypertrophy?
Haven’t You Heard?
As a dude that tends to not sleep a lot due to having family responsibilities (I have a beautiful wife and three kids), obtaining my doctorate in physical therapy school, managing my business as a remote strength coach, pretending to be a doctor on the internet, and training myself, I’ve heard plenty of those late night infomercials about “confusing the muscles” in order to get your body more shredded than shredded cheese, and how easy it is to get strong just as long as you keep changing your workouts. So the question is: what is “muscle confusion”, and can it help me get jacked and tan? Also, for all of my fellow strength oriented peeps out there, can it make me stronger? Let’s look into the literature!
Nerd Article:
Comparison of Periodized and Non-Periodized Resistance Training on Maximal Strength: A Meta-Analysis. (Williams et al. 2017)
What Did They Do Man?
The research nerds looked at the research of a bunch of other research nerds and compared the strength gains of the subjects maxing out in the squat, bench press, or leg press. Each subject was assigned into one of the three groups for an average of 14 weeks, with the total volume of training typically equal between the groups. Some of the studies did a better job of equating the weight in addition to the sets and reps:
- Daily/Weekly Undulating Periodization - Switching between heavy weight/low reps and light weight/high reps every session/week.
- Linear Periodization - Starting with light weight/high reps and building up to heavy weight/low reps.
- Non-periodized programming - Same sets and reps for all the sessions.

Say What!?
So before I go on, I’m sure you are asking: “Hey handsome Dr. Al, what the hell is ‘periodization’ and how does that differ from programming?!”. Well, I’m glad you asked, but please, just call me Handsome Al, as I am currently completing the final year of my clinicals before I graduate. However, an official Ph.D in exercise physiology named Mike Zourdos said it best with “periodization is the long term trend of what you’re doing”. It is the manipulation of training variables to maximize performance at a specific time frame. Think about how an Olympic athlete would structure different volume and intensity within four years in order for the athlete to have peak performance come competition day. Programming, on the other hand, is short term fluctuations in sets and reps that you are currently doing. Periodization dictates programming because with programming, the short term nuances are in place to accomplish the overall goal in the given time frame, whether its performing cluster sets to achieve higher volume in the beginning of a powerlifting meet prep, or performing heavy singles two weeks out from the competition.
Dude, What Happened?
So in the meta-analysis, (an examination of independent studies to see if there’s a trend), the authors found that from the 18 studies that fit their criteria, the magnitude of improvement in strength for each of the two types of periodized resistance was greater than the non-periodized training. In the data analysis, the relationship between two variable results are measured by the “effect size”, or “Cohen’s D”. A small effect would be a Cohen’s D value of around 0.2, with a moderate effect being around .5, and anything larger than .8 being considered a large Cohen’s D (insert inappropriate joke here). The authors found that there was a moderate effect size of .43 in favor of periodization.
Why The FAQ Should I Care?
So how exactly does muscle confusion get you your shredded abs and the strength to match the impressive physique?
In Terms of Strength
Well, the answer is dependent on whether you think structuring changes in sets and reps should be labeled as “muscle confusion”. Personally, I do not, as I view those changes as the timing of volume and intensity, whereas the late night infomercials talk about constantly changing exercises every day in order to keep the stimulus novel. However, any decent strength coach knows that this is blasphemy, as it contradicts the core principle of The Law of Specificity, which states that training should be relevant and appropriate to the desired sport. In simple terms, if you want to be good at squatting heavy weight, then squat heavy weight! Cue the mind blown sound effect. In addition, the more advanced the athlete is, the more specificity the athlete will need in order to continue to make progress. One thing to note is that of the 18 studies that were included for analysis, only two reported the subjects being “resistance trained”, (Monteiro et al. 2009 & Baker et al. 1994) with the subjects benching and squatting an average of their body weight.
For Benching and Squatting
In an article written by Greg Nuckols, he conducted his own unofficial systematic review and found that linear periodization and undulating periodization affected bench press strength when compared to non periodization. For the squat, however, the opposite was true. Nuckols believes this is due to the likelihood that the subjects perform the bench press in their own training, compared to the squat (that’s absolutely apparent when going to any globo gym on Mondays). So, the subjects basically would have had significant squat gains no matter what kind of program they were on due to their squats being undertrained.
For Getting Jacked and Tan
Now, when it comes to hypertrophy with periodization, this study did not mention it as one of its outcome measures. However, another systematic review (Grgic 2017) investigates the effects of periodization vs. non-periodized training on hypertrophy, and found that there was no significant difference between the two, meaning that total volume is the primary factor for hypertrophy (shouldn’t be a surprise). One thing to note about Grgic’s study is that these were based on research conducted on untrained subjects, as subjects had beginner gains with as high as 7% lean body mass in 8 weeks in one of the 12 studies included.
In Terms Of Feelings
As a strength coach, sometimes you can increase a client’s total by 150 lbs in a matter of 3 months, but they can still not be satisfied. That is why subjectively, one of the studies (Hoffman et al. 2009) had an interesting survey after the study was conducted. They asked:
- Were you able to maintain the prescribed intensity/volume of my workouts throughout the study?
- Do you feel stronger and more powerful than I did at the start of the study?
- Do you feel that I had sufficient recovery between each workout session?
- Do you feel that the program I was on provided me the best opportunity to increase my strength and power?
Non periodized training scored the highest agreement for question one, linear periodization for question two, and undulating periodization for the last two questions.
The Actionable Take-Aways
-If muscle gain is your priority, then volume is king despite periodization.
-Daily/weekly undulating periodization is great for bench strength in general.
-If you are relatively new to squatting, any program organization will work for you.
-If you are an intermediate lifter, I personally program my clients with daily/weekly undulating periodization alternating heavy deadlifts for the first week and heavy squats/bench for the next week with great results.
-Subjectively, people tend to feel more recovered and satisfied from changing sets and reps more often, and a great coach would be able to program around life events as well.
Cherry Picking!
Like I stated in my last article on “Does Squatting Like An IG Thot Increase Gains?”, the different literature mentioned in this article are just a few of the vast majority on the given topic and methods the researchers use. Currently, there is no unanimous “scientifically proven” way to program for strength and hypertrophy. But, that’s the whole point of science, as it’s not about “proving” anything, but rather gathering enough evidence to tentatively come up with the best possible explanation in order to weigh the pros and cons of the reasons on why we do certain things in the gym. Please feel free to comment below, or ask any physical therapy, powerlifting, and programming questions that you want answered in the next blog!
References:
Grgic J, Lazinica B, Mikulic P, Schoenfeld BJ,