Cardiac Injury Markers in Non-elite Marathon Runners
Bibliographic record
Abstract
An elevation of cardiac injury markers including creatinine kinase (CK), myoglobin (Myo) and cardiac troponin T (cTnT) has been observed in elite athletes following strenuous exercise. The mechanism and significance of this observation however have not been fully elucidated. The goals of this study were: 1) to determine whether these changes in biomarkers also occur in a large, heterogeneous group of non-elite athletes; and 2) to identify possible clinical or biochemical associations. We recruited 129 non-elite runners in 2006, 61 individuals who were taking part in the half (13.1 miles) marathon and 68 individuals participating in the full (26.2 miles) marathon. Demographic data and blood samples were collected for analysis of CK, Myo, cTnT, and Creatinine (Cr) levels within two hours of race start, at race completion, and 1-h post-race for both patient cohorts. In the 61 individuals (40 males, 40+/-12 yrs) completing the half marathon in a mean time of 150+/-20 min, 90.3%, 65.2%, and 30.6% of the subjects exhibited significant elevations in Myo, CK, and cTnT, respectively immediately post race and 100%, 74.9% and 45.9% in the same biomarkers one hour-post race. In the 68 individuals (44 males, 42+/-14 yrs) completing the full marathon in a mean time of 310+/-30 min, 95.3%, 70.2% and 35.7% exhibited significant elevations in Myo, CK and cTnT respectively immediately post race and 100%, 78.5% and 52.8% in the same biomarkers one hour-post race. The elevation in cTnT levels post-race were modestly associated with the time required to complete the race for the entire cohort of marathon runners. The serum levels of Cr, CK, and Myo post-race did not correlate however with age, sex, BMI, level of training, or prior marathon experience. Elevations of cardiac injury markers in non-elite athletes are extremely common following the completion of endurance events and correlate to the increased endurance time. Whether the increase in the levels of these enzymes represents true myocardial injury or a result of the release of cTnT from the myocytes requires further investigation.
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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 | 0.001 | 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".