Periodisation
Evidence: limited
The general base-to-specific logic is sound. Claims that one specific scheme reliably beats another are weakly evidenced.
Periodisation is the organisation of training into phases over weeks and months, typically progressing from a general base through more specific work to a taper before competition. The broad logic, progressive overload and a base-to-specific sequence, is uncontroversial and supported in principle.
The weakly evidenced part is the belief that a particular scheme is superior to another. Block periodisation, which concentrates training stress into sequential focused blocks, is proposed as better than traditional concurrent development for trained athletes (Issurin 2016), but the head-to-head literature is small, heterogeneous and at high risk of bias, with no robust general superiority (Mølmen et al. 2019).
Kiely’s critiques are the sharpest, and they are well argued. The major periodisation models share a mid-twentieth-century heritage whose founding assumptions, including a literal interpretation of the general adaptation syndrome, are no longer scientifically justifiable; head-to-head comparisons of schemes tend to give equivalent group outcomes while individual responses vary widely (Kiely 2012; Kiely 2018). His conclusion is not to abandon planning but to make it responsive and individualised rather than formulaic.
The honest summary: structure training, progress it, and taper for races, because that general approach is sound. Treat any claim that scheme X reliably beats scheme Y as poorly supported, and tune the plan to the individual rather than to a named template. This is closely related to the supercompensation and adaptation model, whose textbook curve is itself an oversimplification.
A sensible default
What to do given the weak evidence
Since no scheme is proven superior, the defensible approach is the simple one almost every system shares: build a base of mostly easy volume, then layer on progressively more race-specific intensity, then taper for the race. Make it responsive rather than rigid, adjusting from how training is actually being absorbed (monitoring) rather than forcing a fixed template. The general progression helps; the elaborate scheme on top of it is where the evidence runs out.