The Importance of 'Durability' in the Physiological Profiling of Endurance Athletes
Core Concept
Durability — the authors' definition: *the time of onset and magnitude of deterioration in physiological-profiling characteristics over time during prolonged exercise.*
Physiological profiling (the attributes measured in routine lab or field testing) is normally done in well-rested athletes.
The paper argues, from the literature and from field data presented in it, that these attributes are not static: they change over time during prolonged exercise.
If that shift is not accounted for, it affects the accuracy of the profile for: intensity regulation in long sessions and competitions, quantifying training adaptations, training-load programming and monitoring, and predicting performance.
Current profiling models do not account for these shifts; the authors call for models that do and that quantify each athlete's durability, and they propose directions for research and applied practice.
Key Findings — what the abstract does and does not give
It gives the definition, the argument and the list of use-cases above.
It gives no numbers: no percentage decline of threshold power, no economy or heart-rate drift figures, no thresholds for "good" or "poor" durability. Any such figures quoted for this paper are not from it.
Practical Application
Conceptual review by the group that coined the term: the thresholds, economy and heart-rate response an athlete shows fresh are not the ones they show after hours of riding, and standard profiling ignores that — so a fresh FTP or lactate test tells you what the athlete can do at hour one, not at hour four, and a plan built only on fresh numbers will mis-pace long sessions and races.
Assess durability as its own quality, separate from peak capacity: the paper's premise is that two athletes with the same fresh profile can deteriorate very differently over a long effort. In practice that means looking at how power at a fixed heart rate, heart rate at a fixed power, and RPE drift late in long rides, not only at test results.
Inference, not tested here: because fresh capacity and durability are proposed as distinct, training that raises FTP does not automatically raise durability; long steady work, race-length efforts and fuelling are the levers usually named — this paper proposes the construct, it does not test interventions.
Not from this paper; the base's own practice: compare a repeatable effort (e.g. a hard 5-20 min block) done fresh and again after 2-3 h of steady riding; the size of the drop is the athlete's working durability number, tracked against their own history rather than against a fixed cut-off.
Limitations
Narrative/conceptual review: it argues for a construct and a research direction, and presents field data as illustration, not as a controlled study
No quantitative model, thresholds or normative values are proposed in the abstract
Molecular or training mechanisms of durability are not part of this paper
How this entry was checked and changed
Why this level
regraded 2026-09-27 from A: narrative review without systematic method, from the group that defined the construct
Content correction 2026-09-27
"Effective sustainable power ~14% lower (per Mateo-March)", "FTP decay ~14%", "economy worse by 3-5%", "LT%VO2max decay 2-5%", "cardiac drift 5-8 bpm over 3-4 h", "VO2max decay ~0%", "lactate threshold shifts right" -> deleted; none of it is in this abstract, and the 14% figure is not in Mateo-March either (REF-192 publishes −6.0 to −9.7% after 45 kJ/kg).
"Durability Index DI = … ; >90% WorldTour, 85-90% competitive amateur, <85% low" -> deleted; a house formula and cut-offs, not from the paper.
"Molecular mechanisms of durability improvement" section (mitochondrial density, glycogen, PGC-1α, antioxidant enzymes) -> deleted; not in this paper.
Level A -> B+ (narrative review); Sport "cycling" -> general (abstract: endurance athletes).
Cross-references to duplicate stubs repointed to their canonical entries (REF-162->REF-306); the stubs were emptied on 2026-09-27.