Durability is a real, largely separate dimension of endurance performance — but the "independent of fitness" claim is mostly elite-sample evidence
Interpretation
The conceptual case for durability as a distinct fourth dimension (alongside VO2max, economy, threshold) is well-argued and taken seriously across multiple 2023-2025 papers. But almost all of that evidence comes from small, male, trained-to-elite cycling samples. The one amateur dataset we have (Barsumyan et al. 2025) complicates the clean "independent of your engine" story — don't over-claim what the elite literature shows for an age-grouper.
Practical implication
Treat fresh-state fitness tests (FTP, VO2max) and late-race power retention as two separate things to assess, not one implying the other. Don't assume a strong fresh-state number guarantees durability, and don't assume durability training transfers identically to amateurs as it does to pros.
Sources
5 sources, independently verified.
Proposes physiological resilience as a fourth dimension of endurance performance alongside VO2max, economy, and threshold — all three established pillars deteriorate during prolonged exercise, with critical power falling by an average of 10% (range <1% to ~32%) after 2 hours of heavy cycling.
Reviews what's known about training physiological resilience: training consistency and large accumulated volume over years, regular prolonged sessions (especially with race-pace-or-above efforts), and heavy strength/plyometric training all show positive associations.
Experimental Physiology 110(11):1612-1624. Reviews how durability (resilience to deterioration of physiological variables during/after prolonged exercise) is currently measured, noting most athlete profiling is still done in a rested state despite performance happening in a fatigued one.
Volume 139(6):1703-1709. A viewpoint proposing a conceptual expansion of endurance performance through four distinct constructs — durability, fatigability, repeatability, resilience — arguing classical physiological markers alone can't explain individual performance differences in prolonged/repeated efforts. This is the paper the terminology dispute largely centers on.
Volume 7, article 1530162. Measured power/HR for 5- and 20-min efforts fresh vs. fatigued (70-80% initial power until 1,000 kJ completed). Successful amateurs showed only a 6.5% power drop in the fatigued 20-min effort vs. 12.5% for less-successful amateurs — the key amateur-population counterpoint to durability research otherwise dominated by elite/pro samples.