Arterial stiffness and subendocardial viability ratio: temporal responses to ultra-endurance exercise
Bibliographic record
Abstract
Ultra-endurance exercise causes significant cardiovascular stress, yet the vascular responses during recovery remain incompletely understood. This study examined the short- (12–18 h) and longer-term (7 and 28 days) effects of a long-distance triathlon on arterial stiffness and subendocardial viability ratio (SEVR) in novice triathletes. Eleven participants (two females, nine males), novice to long-distance exercise events, completed cardiovascular assessments at baseline (pre-race), 12–18 h post-race, and 7- and 28-days post-race. Measures included carotid-femoral pulse wave velocity (PWV), augmentation index (Aix), and SEVR, obtained via applanation tonometry. PWV remained unchanged at all post-exercise time points ( P = 0.310). Aix showed significant reduction at 7 days post-event ( P = 0.024), though this effect was abolished after normalizing values to a heart rate of 75 beats per minute (Aix75, P = 0.162). SEVR decreased significantly 12–18 h post-race ( P < 0.001), indicating a transient imbalance between myocardial supply and demand, likely driven by elevated heart rates and reduced diastolic perfusion time. SEVR returned to baseline by 7 days post-event. These findings suggest that while no sustained changes in arterial stiffness were observed, hemodynamic conditions during recovery may signify altered myocardial supply–demand balance in novice athletes. Further research is needed to explore these mechanisms, with enhanced temporal resolution, to better understand the cardiovascular implications for novice endurance athletes.
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How this classification was reachedexpand
Full frame machine prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. The Gemma side is a direct model label for every work in the frame, read from the title-only record. The Codex side is a classifier learned from the 10,348 direct Codex labels and calibrated to design-weighted sample rates; fields without enough sample support carry no Codex call. Candidate is the union of the two sides; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels.
Distilled classifier scores by category (both heads)
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.000 | 0.001 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.000 | 0.000 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.001 | 0.000 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from itClassification
machine, unvalidatedMachine predicted; a candidate call from one source (direct Gemma or distilled Codex), not a consensus.
How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".