REF-477 · Meixner, Joyner & Sperlich, 2025 · Journal of Applied Physiology · Paper

Conceptual review distinguishing four endurance-performance constructs and proposing a unified taxonomy

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

Core Contribution

Demonstrates that durability, fatigability, repeatability, resilience are four DIFFERENT constructs that require different:

1

Definitions

2

Assessment methods

3

Training stimuli

4

And have different physiological substrates

This distinction matters because the popular literature (including wearable marketing) often uses these terms as synonyms — which leads to choosing the wrong stimuli for the goal.

The Four Constructs

Not from this paper; the base's own practice: the time-scales, stimuli and assessment methods listed under each construct are the base's operational reading of the four terms, not quotations from the Viewpoint (full text not checked; no abstract exists).

1. Durability — the ability to maintain physiological characteristics (CP, LT1, LT2, gross efficiency, economy) over prolonged work (Not from this paper; the base's own practice: >1-2 hours, see REF-195).

Time-scale: hours
Stimulus: prolonged exercise exposure, glycogen management, fat oxidation
Assessment: pre/post-fatigue power tests after a long preload (Not from this paper; the base's own practice: 2-4 h, see REF-195, REF-143)

2. Fatigability — acute susceptibility to fatigue under a given stressor: how quickly power drops during a single maximal effort.

Time-scale: seconds-minutes
Stimulus: high-intensity work, buffering, neuromuscular drive
Assessment: force-time curves, EMG, sustained max efforts

3. Repeatability — the ability to reproduce a result across sequential efforts with limited recovery (e.g., repeated sprints, race surges, stages of a multi-day race).

Time-scale: minutes-hours (between efforts)
Stimulus: SIT, PCr resynthesis training (via aerobic capacity), short-interval VO₂max
Assessment: repeated sprint protocols, between-effort power retention

4. Resilience — a broader concept: the physiological ability to withstand and recover from multiple/diverse stressors simultaneously (training load + heat + altitude + sleep + nutrition).

Time-scale: days-weeks
Stimulus: progressive multi-stressor exposure, camps, periodization discipline
Assessment: integrated markers — HRV, RHR, performance consistency under load

Key Findings (insight)

Inference, not tested (the base's reading of the title claim): these four constructs correlate but are not reducible to one another. An athlete can be:

High durability + low repeatability (classic diesel-stayer without an anaerobic engine)
High repeatability + low durability (sprinter in team sports)
High resilience + moderate durability (an athlete who tolerates camps well)
Etc.

Training one construct does not necessarily improve the others. A program must deliberately address the construct that dominates the goal.

Practical Application

Durability, fatigability, repeatability and resilience are four different constructs, not synonyms (Meixner, Joyner & Sperlich 2025, Viewpoint — no data). Use the entry to keep the words apart when an athlete or a wearable mixes them; use REF-195/REF-143 for durability numbers and SYNTH-32 for the durability framework (the separate four-construct taxonomy entry is superseded by it).
Training one construct does not automatically train the others (Inference, not tested: the base's reading of the Viewpoint's distinction).

Limitations

Conceptual Viewpoint — synthesis, not new data; no abstract exists, so the entry's detail could not be checked against the paper (level C+)
Boundaries between constructs are blurred in practice (especially resilience ↔ durability)
Assessment methods for fatigability and repeatability are less standardized than for VO₂max or LT
Some proposed stimuli are extrapolated from other sports
How this entry was checked and changed
Why this level

regraded 2026-09-27 from B: Viewpoint / conceptual article (expert opinion, no data, no abstract published); earlier note: downgraded from A on Viewpoint format

Content correction 2026-09-27
Level B -> C+: a Viewpoint with no data is expert opinion under the rubric; no abstract is published, so nothing beyond the title claim could be verified.
Time-scales (>1-2 h, 2-4 h preload), stimuli and assessment methods per construct relabelled as the base's own practice, pointing to REF-195/REF-143 for the durability figures; the "not reducible to one another" section marked as inference.
Cross-reference descriptions checked against the cited entries' current content; wrong years, wrong entries and claims the cited entry does not make were corrected.
2026-10-01: cross-reference repointed from a merged framework to the one that replaced it (SYNTH-01→31, 05→34, 09→70, 12/15→32, 19→26).
2026-10-01: citation of the superseded pointer SYNTH-15 repointed to SYNTH-32 as the durability framework; SYNTH-32 holds no four-construct taxonomy, so that description was dropped, which carries the cited content.