Why Debate Periodization in the First Place?
If your first instinct is to ask “who cares?,” you’ve already answered the question…
A month or so ago, I wrote what became a pretty heated article entitled “The Death of Periodization.” Upon completion, and after posting it on our Instagram and my own personal LinkedIn page, I did something I rarely ever do: engage in online debate.
Now, a month on, a few key lessons have been learned that I think are worth sharing. I’m not going to go so far as to say that this will be the last time MOPs & MOEs engages with Periodization, but I do think it’s worth addressing why we chose to even pick this fight in the first place.
The flow I’m going to use is based on the ways in which most of these debates played out. In an attempt to make this more than just “Drew’s two cents,” I’ll be including some links to additional supportive reading at the end of some of the sections when relevant.
We’ll move through this article as follows:
(1) We have a conceptual problem → (2) that is built upon shaky foundations at best → (3) the research doesn’t even validate what we think it does → (4) the concept has become so broad that it can’t even be separated from coaching in the first place → (5) which raises the question: what exactly are we defending??
Before we begin, I want to be very clear about something:
The question isn’t whether or not coaches should plan. The question is whether periodization has become such an unquestioned assumption that it now limits our ability to observe athletes objectively.
Perhaps the most common rebuke online boiled down to “if you’re not periodizing, you aren’t programming with any sort of logic in the first place.”
This is unequivocally false, as you should hopefully see by the end of this article.
So, I present to you the five reasons why we should debate periodization in the first place.
1) Treating Periodization as the Only Way to Think Limits Young Coaches
When I debate periodization, what I’m really getting after is paradigms that limit how expertise develops. Think about it…most young coaches don’t actually learn to coach first; they learn terminology and systems.
By the time someone graduates with an exercise science degree or completes their CSCS, they’ve already been taught that planning, sequencing, variation, progression, and periodization are almost synonymous. The result is that they begin interpreting athletes through a predefined conceptual lens before they’ve accumulated enough coaching experience to question whether or not that lens is actually helpful.
To illustrate my point, I want you to imagine two novice coaches.
Coach A is taught to ask “which periodization model should I use?”
Coach B is taught to ask “what is this athlete actually showing me today?”
Those two questions produce fundamentally different coaching behaviors. The first begins with a framework; the second begins with observation.
What’s interesting is that most of the coaches who disagreed with my initial article seemed to think that they were operating in line with Coach B, when in reality they had already asked the same question as Coach A, and were then trying to introduce flexibility into a framework that was caging them in.
One of the most useful ideas from the philosophy of science is a famous statement by Alfred Korzybski:
“The map is not the territory”
Periodization (pre-planned phases, blocks, sequences, etc) is a map. The athlete in front of you (their likes, dislikes, stressors, etc) is the territory. Maps are useful, but only until they prevent us from seeing the terrain itself.
Another legend from the field of scientific philosophy, Thomas Kuhn, argues in The Structure of Scientific Revolutions that paradigms shape not only our answers, but what questions we think to ask in the first place. Once a framework becomes dominant (i.e. all training must be periodized), alternative interpretations become increasingly difficult to imagine (i.e. can you even train without forecasting adaptations??).
That is precisely why it matters that we question periodization in the first place. It’s not because planning is bad; it’s because no framework should become so invisible that we cease to even believe we can function without it.
Supporting References
2) The Scientific Foundation of Classical Periodization has Changed
I don’t want the takeaway from this section to simply be “General Adaptation Syndrome is wrong.” It has its historical merits, just not within the context of how we now know human beings actually perceive, internalize, and respond to stressors.
Put another way, our understanding of adaptation has outgrown a simple Alarm-Resistance-Exhaustion curve.
As we showcased in our earlier article, much of classical periodization traces back to Hans Selye’s General Adaptation Syndrome (GAS), developed from laboratory studies of rodents exposed to generalized physiological stress. The model describes a predictable sequence of alarm, resistance, and exhaustion.
GAS is so ingrained in our concept of training design that the NSCA refers to it as a central concept, which is insane to think about when you realize that modern stress theory has moved on.
How, you might ask?
Let’s look at one key element: The Nonspecific Response. In GAS, Seyle effectively argued that every stressor (cold, heat, trauma, psychological, etc) produces the exact same uniform biological reaction.
We all know this isn’t true.
Our modern scientific understanding of stress, on the other hand, shows that specific stress pathways exist. The body’s biological response varies significantly depending on whether the stressor is physical (i.e. losing a bunch of blood) or purely psychological (i.e. public speaking).
Perhaps more importantly, Seyle completely ignored our cognitive appraisal of a perceived stressor. Seyle viewed stress as a purely physical, reflexive feedback loop based on his observation of animal models (i.e. poisoning rats). What we now know to be true is that perception is everything. Stress is highly mediated by how an individual evaluates a threat. A simple example is how you feel going into a back squat. We’ve all been there…if we assume it will feel heavy, it’s likely to. If the music is blaring and we’re pumped up, that same weight may feel significantly lighter. This matters, and GAS doesn’t account for it.
Historically, Seyle’s framework influenced early theories of training adaptation because it suggested that organisms (athletes) respond to stressors in relatively predictable ways. When we allow that to be true, we’re able to get away with predictive models of training adaptation. If the paradigm within which we’re operating tells us that a back squat will impose the same amount of “stress units” on every athlete we work with, then why the hell shouldn’t we just write 12 weeks of training in advance and call it a day??
The problem is that, as described, modern adaptation science has become dramatically more complex. Any coach worth their salt knows that the athlete’s rate of adaptation is simultaneously influenced by things like
training history
genetics
sleep
psychological stress
nutrition
injury
motivation
environmental stressors
Rather than a single stress-responsive curve, adaptation appears to emerge from a complex interaction of biological, psychological, and environmental constraints. John Kiely has argued that many deterministic assumptions inherited from classical periodization no longer align well with these more contemporary findings. His critique isn’t that adaptation doesn’t occur, but that our ability to predict its trajectory has often been overstated. Likewise, Buckner et al. questioned whether Selye’s original work was ever intended to support long-term resistance training models in the first place.
The point isn’t that GAS has no value.
It’s that we should be scrutinizing an entire coaching philosophy built upon a simplified, outdated stress model.
Supporting References
Periodization Theory: Confronting an Inconvenient Truth, John Kiely
The General Adaptation Syndrome: Potential Misapplications to Resistance Exercise, Samuel Buckner
3) The Research Mostly Supports Variation, Not Periodization Itself
One of the biggest assumptions in exercise science is that evidence supporting training variability automatically validates periodization. But those are not necessarily the same thing.
This is why, as Alex often says, it’s important to read the Methods section of a research paper.
Most periodization studies compare varied training against non-varied training. Predictably, varied programs usually outperform programs that have athletes/volunteers completing the same exact workout ad infinitum.
But ask yourself a very simple question: does that prove that periodization works, or does it simply show that variation is useful?
Nunes and colleagues argued this exact point: that many periodization studies never actually test the central claims of periodization. Instead, they compare different methods of organizing variation while assuming that the underlying theory (periodization) is already correct.
Put another way, much of the literature tells us that what matters is that we change training variables, not that long-range predictive planning is the mechanism responsible for athlete improvement.
That’s a very, very important distinction.
As I argued in my article in favor of navigation versus planning, I can adjust training variables in response to the athlete’s real-time feedback without relying on some misinformed long-range predictive periodization structure.
I can plan without periodizing.
Imagine if nutrition research repeatedly showed that eating a variety of different foods produced better health outcomes than eating only chicken breasts. That wouldn’t validate a specific dietary philosophy; it would validate dietary variety.
Likewise, evidence supporting variation shouldn’t automatically be interpreted as evidence supporting every theoretical claim attached to periodization.
As Alex says…read the Methods section.
Supporting References
4) Coaches Are Unable to Separate “Training” from “Periodization”
This was, far and away, the most surprising takeaway from my weeks of online debate. For many coaches, whether they realize it or not, they are unable to even begin to separate the idea of training from the concept of periodization.
Let’s rehash:
Training is the process by which we, as coaches, take an athlete from a starting point to some future end state. It’s the myriad stressors we either directly apply or try to account for along the way.
Periodization is a lens through which we can view training that gives us a framework for predicting hoped-for outcomes far into the future. It relies on the ability to forecast outcomes, i.e., predetermine what an athlete will be capable of on some future date/time (see: peaking).
These are two different things. Periodization is a way in which we can choose to execute training, but we are not beholden to it as the ONLY way.
After publishing the Death of Periodization article, one thing became very clear: many critical responses weren’t actually defending a specific theory. Instead, they were arguing that virtually every form of organized training is periodization.
For example:
“if you plan training, you’re periodizing”
“if you adapt training in response to athlete feedback, that’s still periodization”
“if you sequence training at all, that’s periodization”
“every coach periodizes”
Or, perhaps even more common, some version of:
Them: “I was taught XYZ Periodization Model, but no coach that I’ve ever seen actually sticks to these things dogmatically”
Me: “Ok, then why are we teaching it as the only way to design training?”
Them: “Uh, because science…”
Whether you realize it or not, what’s happening here is that the concept of periodization has ballooned to the point that it now apparently includes planning, adaptation, progression, variation, sequencing, coaching, hell…it’s basically an all-encompassing sport science term for “any logical thought.”
If periodization simply means “organized training,” then the term stops distinguishing one coaching philosophy from another. Concepts are useful because they create distinction. When every possible coaching behavior falls under the same label, the label begins to lose explanatory value.
And let’s be very clear: from the outset of the Death of Periodization article, the entire purpose was to critically examine periodization as a model for predicting and forecasting training outcomes, not as a vague catch-all term for the entire world of human performance.
Karl Popper argued that scientific theories must expose themselves to the possibility of being wrong. If every counterexample can simply be reclassified as another form of periodization, then the concept becomes increasingly difficult to test or falsify. That’s not necessarily evidence that periodization is false, but it does suggest we should ask whether the concept has become so broad that it no longer helps us think clearly.
5) If Nobody Can Define Periodization, What Exactly Are We Defending?
Another takeaway from this crusade that is incredibly frustrating: no one can actually agree on a definition of periodization. Virtually everyone insists that they support periodization, yet very few people define it the same way (see Point #4).
Some folks even accused me of not defining periodization, which I rally against wholeheartedly. In the Death of Periodization article, I was critically examining the overarching theme across all Periodization models (block, triphasic, West Side, undulating, linear, etc etc):
“The fundamental assumption of Periodization is this: If we manipulate training variables in predetermined ways over predetermined periods, predictable biological adaptations will occur on a predictable schedule.”
-Me
Just take a second and compare the supposed “periodization literature”:
Matveyev emphasized long-term sequencing based on predictable adaptations
Bompa emphasized systematic planning towards peak performance
Issurin emphasized concentrated loading
the NSCA defines it broadly as the logical sequencing and integration of training interventions
You see what’s happening here, right? Many coaches simply describe it as “good planning,” yet critics of periodization recognize that the classical literature defines it as predictive adaptation models.
These aren’t small semantic differences, as many Instagram and LinkedIn detractors would have you believe.
These are fundamentally different concepts.
If the definition changes every time someone challenges it, meaningful scientific discussion becomes nearly impossible.
Definitions aren’t semantics. Definitions determine what questions we ask, what hypotheses we test, how studies are designed, and how evidence is interpreted. Without a shared definition, disagreements become impossible to resolve because participants are no longer debating the same idea.
So, perhaps the biggest reason to debate periodization is simply this:
Science progresses by refining ideas until they become more precise, not by protecting vague ideas from criticism.
Wrapping It All Up
I don’t want to try and “win” the debate here, but I do want to bring all of this back to first principles.
None of what I’m trying to say should be taken to mean that coaches shouldn’t logically plan training. It doesn’t mean that progression is unnecessary or that variation is optional. It also doesn’t mean that you should totally wing it as a coach and hope for the best.
It simply means we should be willing to separate those unquestionably valuable coaching practices from the inherited theories we’ve used to explain them. If, after careful scrutiny, periodization remains the best framework for training tactical athletes, then it will emerge stronger for having been challenged.
But if the conversation reveals that we’ve been conflating planning, variation, adaptation, and coaching under a single increasingly ambiguous term, then asking difficult questions isn’t an attack on coaching; it’s one of the most coach-like things we can do.
That…along with actually reading the Methods section.