Is block periodization proven better than traditional training?
No. This influential review argues for it but brings no new data; trials at equal load find small or no differences (REF-946, REF-098). Theory, C+.
Issurin argues that the theory of training periodization was set out about five decades ago on limited research and has hardly changed since, while elite sport changed a great deal, so contradictions grew between the traditional model and high-performance practice.
He names four limitations of traditional periodization: conflicting physiological responses from "mixed" training aimed at many abilities at once; excessive fatigue from long periods of multi-targeted training; insufficient stimulation from the medium- and low-concentration workloads typical of mixed training; and the inability to deliver several peaks in a season.
Block periodization is offered as the answer: a sequence of specialised training cycles (blocks), each with highly concentrated workloads aimed at a minimal number of target abilities, developing selected abilities one after another rather than all together.
The review sets out the model's general principles, a taxonomy of mesocycle blocks and guidelines for compiling an annual plan.
Our reading: the four limitations are asserted in the abstract, not shown; since 2010, trials that compare block with traditional organisation at equal load in endurance athletes have found small or no detectable differences (REF-946, REF-098, REF-1216, REF-1217), so the model is a workable option rather than the superior one.
A published letter, Kiely's "block periodization: new horizon or a false dawn?" (Sports Med 2010;40(9):803-5, with an author reply), disputed the review at the time; it was not read for this entry.
Protocol
Key Results
| Claim in the abstract | Status here | What the base holds on it |
|---|---|---|
| Mixed training gives conflicting physiological responses | asserted, not tested | At equal load over 12 weeks, block and traditional gave similar time-trial gains in 30 trained cyclists (REF-098, B+); six small pooled studies gave block a small VO2max and Wmax edge whose prediction intervals cross zero (REF-946, B+) |
| Long multi-targeted periods cause excessive fatigue | asserted | Measured only for blocks, and against the claim: in junior skiers a 9-HIT loading week lowered perceived recovery against the even spread (REF-1216, B+), and a concentrated easy-volume week lowered mood and perceived recovery (REF-1217, B+); no entry measures fatigue from long multi-targeted training |
| Medium- and low-concentration workloads under-stimulate | asserted | One-week concentrated MIT or HIT blocks raised threshold or VO2max power in well-trained cyclists (REF-137, REF-048); the same 9 HIT sessions in one week or spread over three showed no evidence of a difference in junior skiers (REF-1216) |
| Traditional periodization cannot deliver multiple peaks | asserted | Multiple peaking was essentially unstudied (REF-109, C+) |
| Train a minimal number of target abilities per block, in sequence | proposed | Tested in elite kayakers across two seasons (REF-1221, B) and described in one world-class skier (REF-1222, C+) |
Mechanisms
Practical Application
Limitations
How this entry was checked and changed
(from the abstract) — narrative review without systematic method; it argues for a model rather than testing it, and its author is that model's principal advocate. The residual-training-effect durations quoted from Issurin's work are the author's theory, not measured decay