REF-945 · Kiely, 2012 · International Journal of Sports Physiology and Performance, Vol. · Paper · PubMed

Periodization paradigms in the 21st century: evidence-led or tradition-driven?

C+thin evidenceMeasured on a mixed groupWritten before October 2026, being re-checked

Kiely reviews the assumptions behind periodization models. The models proposed by influential theorists appear to differ substantially, but at a deeper level share a cultural heritage and a common set of historically pervasive planning beliefs and assumptions, some of which are no longer scientifically justifiable yet remain deeply embedded.

Evidence that training responses vary extensively, depending on multiple underlying factors, challenges generic methodologies founded on overly simplistic rule-based decision making for complex biological systems.

The review does not call for rejecting periodization theories; it calls for awareness of their strengths and weaknesses, for realigning them with contemporary elite practice and modern scientific models, and for sensitive and responsive training systems that let customised, context-specific planning solutions emerge.

Participants

Not applicable (narrative review).

Protocol

Narrative, critical review of the planning assumptions shared by periodization models; no search strategy or pooled analysis is described in the abstract.

Key Results

Periodization models that look different on the surface rest on a common set of historically pervasive planning beliefs and assumptions.
Certain of these assumptions are, in the author's judgement, no longer scientifically justifiable, yet remain embedded.
Training responses vary extensively depending on multiple underlying factors, which challenges applying generic, rule-based methodologies to planning.
The purpose is not a whole-scale rejection of periodization theories but a refined awareness of their strengths and weaknesses.
Recommendation: more emphasis on sensitive and responsive training systems that facilitate customised, context-specific planning solutions.

Practical Application

"Which periodization model should I follow?" This critical review argues that the named models share the same untested planning assumptions and that individual responses to training vary extensively — so no model is owed loyalty, and the plan should be built to respond to how this athlete is actually adapting. Plan a structure, then let monitoring change it.
Not from this paper; the base's own practice: count back from the A-races and move from general to specific, as in SYNTH-76; treat that layout as a default to be revised, not a rule.
The comparative trials do not overturn this: block against traditional is in REF-946 and REF-103, reverse against traditional in REF-948.
This is an argument, not a trial. It cannot be cited as evidence that a responsive plan outperforms a fixed one.

Limitations

Narrative review and opinion; no systematic search, no data.
Does not test responsive against pre-planned training.
Written from the abstract and record metadata only (full text not read).
How this entry was checked and changed
Why this level

narrative review without systematic method; an argument, with no data of its own