REF-762 · Bernat-Adell et al., 2021 · Journal of Strength and Conditioning Research, Vol. · Paper · PubMed
Recovery of Inflammation, Cardiac, and Muscle Damage Biomarkers After Running a Marathon
In 86 marathon runners sampled from 24 h before the race to 192 h after it, four blood markers rose and came back on different clocks: troponin (hs-TnT) was back to baseline by 96 h, creatine kinase by 144 h, lactate dehydrogenase only by 192 h, and C-reactive protein was still significantly elevated at 192 h. Slower runners had lower marker levels, and greater energy expenditure went with higher LDH, CK and hs-TnT.
Participants
n=86 marathon runners. Age, sex, finish times and training status are not given in the abstract.
Protocol
Experimental repeated-measures design, pre-post marathon, no control group.
Blood markers: lactate dehydrogenase (LDH), creatine kinase (CK), high-sensitivity troponin T (hs-TnT) and C-reactive protein (CRP).
Sampling: 24 hours before the marathon, immediately after finishing, and at 24, 48, 96 and 144 hours post-race (the abstract's methods list stops at 144 h, but its results report values at 192 h).
Friedman and Wilcoxon tests against the pre-race value; Spearman correlations with race variables; significance p ≤ 0.05.
Key Results
| Marker | Elevated (vs pre-race, p ≤ 0.001) | Back to baseline | Effect size |
|---|---|---|---|
| hs-TnT (cardiac) | post-race, 24 and 48 h | 96 h — but significant again at 192 h (p ≤ 0.001) | r = 0.519 |
| CK (muscle damage) | up to 96 h | 144 h | r = 0.975 |
| LDH (muscle damage) | at all times through 144 h | 192 h (p = 0.667) | r = 0.807 |
| CRP (inflammation) | post-race, 24, 48, 96, 144 and 192 h | not within the study (still elevated at 192 h) | not given |
Recovery time differs by marker.
Blood levels of the markers were lower with longer race times.
Greater energy expenditure went with higher LDH, CK and hs-TnT.
The abstract gives no absolute marker values, no correlation coefficients for the race-time and energy-expenditure associations, and no direction for the hs-TnT change at 192 h.
Practical Application
In 86 marathon runners sampled up to 192 h after the race, troponin was back to baseline by 96 h, CK by 144 h and LDH only by 192 h, while CRP was still elevated at 192 h (uncontrolled pre-post study). After a marathon the blood takes most of a week or more to settle, and the inflammation marker the longest; legs that feel fine by midweek do not mean every marker has recovered.
Muscle-damage markers are not a return-to-running signal: in REF-761, easy running from 48 h did not change CK or LDH recovery compared with rest. Use this entry for what the numbers will look like, not for when to train.
Inference, not tested here: a routine blood test taken within this window will show race-related rises in CK, LDH, CRP and troponin; tell whoever reads it about the marathon.
Not from this paper; the base's own practice: a troponin rise after a marathon is not a diagnosis either way — chest pain, palpitations, dizziness or breathlessness out of proportion after a race are a reason to see a doctor, whatever the calendar says.
Faster runners and those with greater energy expenditure showed higher markers, so a hard, fast race is expected to leave bigger numbers; inference, not tested here: compare an athlete's post-race values with their own previous races, not with another runner's.
Limitations
No control group and no intervention; descriptive time course only.
The abstract's sampling list ends at 144 h while the results report 192 h values; the full sampling schedule cannot be confirmed from the abstract.
Participant characteristics (age, sex, finish times) and absolute marker values are not in the abstract, so the size of each rise is unknown here.
"Normalising" means no longer significantly different from the pre-race value, not a return to a clinical reference range.
Written from the abstract and record metadata only (full text not read).
Inference, not tested here: the author list and sampling schedule overlap with REF-761, so the two papers may draw on the same marathon cohort; the abstracts do not say.
How this entry was checked and changed
Why this level
uncontrolled pre-post, n=86