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Guest Post: The Truth Behind Muscle Confusion

Today’s post comes from a friend of mine and very talented Strength and Performance Coach. Cory Kennedy, M.Sc. You can find Cory on His Website at

I love broscience…I used to smile every time I heard something exceptionally ‘unfounded by science’ at Extreme Fitness back in the day. Muscle confusion is one of those great terms. It seemed so ridiculous to me then, but it didn’t really bother me, because most of those bro’s didn’t know any real science…

Then I started looking around to many strength and conditioning programs I see and I get the same kind of feeling…Yet our profession is founded by science, so it shouldn’t happen right?

I’m being a little harsh, but hear me out really quick.

Let’s just imagine our body is not too bright…(which is contrary to the truth since it is a magnificent machine, capable of change, learning, and complex coordination!)..and in order for you to make a lasting change to your body, from a training session, you need to be really clear about what you hope to get. Like going to the movies, and at the end of this crazy, action-packed thriller, the director comes on the screen and makes sure to explain it all so everyone in the theatre gets those plot twists (that would be a bit of a buzzkill wouldn’t it?)… Sounds like I don’t give our body much credit!

muscle confusion, bodybuilder, confusion, broscience, training, fitness

Back to my train of thought with muscle confusion. Our body is super-smart, but because of this it is doing a million things at a time. This doesn’t leave it many resources to learn new things. So if I want to teach a specific lesson today, I need to be very clear about what i’m teaching. I need to enunciate.

So why are people training 10 different exercises in one workout? They likely start getting into different qualities..How is the body supposed to know which one to prioritize?

Even though muscle confusion sounds like broscience, strength coaches are doing it all the time. For example, despite wanted to develop power, some will start with jumps and olympic lifts, do some squats in a low-to-mid rep range, then a whole bunch of lunges and hamstring curls or romanian deadlifts at high reps. At the end of the workout there was as much energy spent on high-rep low-intensity work, as low-rep high-intensity exercises. The athlete thinks: “This sure does feel good, my legs are toast, workout was awesome!” They may even grow a little bit. Is that the goal though? Was that what you set out to do? Did that hypertrophy help them win a gold medal, or make that team?

Probably not. Your legs got a little bit better at doing lots of work and it averaged out to a moderate intensity…Was that your goal?

As Steve Jobs once said “People think focus means saying yes to the thing you’ve got to focus on, but that’s not what it means at all. It means saying no to the hundred other good ideas that are there. You’ve got to pick carefully.”

As strength coaches it is really easy to justify putting a wide-range of exercises into your program, since many of which have shown to be effective in the literature and in past experiences. This does not mean it’s appropriate at this given time to have them all in there!

Next time you write a program, make sure you know what you want from it. Then, look at each workout and say to yourself, is it obvious what my goal is? Is this the BEST way to accomplish my number 1 priority of this training phase/block??

We try so hard to be complex that we forget to be simple.

This article was originally written for Razors Edge Performance

By: Cory Kennedy, BPHE, MExSci, CSCS, CISSN


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