The association between marathon running and high-sensitivity cardiac troponin: A systematic review and meta-analysis.

Marathon running can raise cardiac troponin, a blood marker used to detect heart muscle injury, but it has been unclear whether this rise reflects lasting damage. This systematic review and meta-analysis pooled 13 studies involving 824 marathon runners, comparing high-sensitivity cardiac troponin I (hs-cTnI) and troponin T (hs-cTnT) levels before and after races. Both markers were significantly elevated immediately after marathons, hs-cTnI by a mean of 68.79 ng/L and hs-cTnT by 42.91 ng/L. However, hs-cTnT returned to baseline levels 72 to 96 hours post-race, with a non-significant mean difference of 0.11 ng/L.

The authors note that heterogeneity among studies may partly stem from differing reference limits used for hs-cTnT, and interpret the transient rise as unlikely to represent irreversible heart muscle injury.

If you've ever wondered whether running a marathon could stress your heart, this review looked at exactly that question by combining data from 13 studies involving 824 marathon runners. Researchers measured a blood marker called cardiac troponin, which usually signals damage to heart muscle, before and immediately after marathons. Both types of troponin measured (hs-cTnI and hs-cTnT) went up right after the race, which might sound alarming at first.

But when researchers checked hs-cTnT levels again 72 to 96 hours later, they had returned to baseline, essentially where they started before the race. This pattern suggests the rise reflects a temporary response to intense exercise rather than lasting heart damage, according to the study authors. It's worth keeping in mind that the studies included varied in how they defined normal troponin ranges, which made it harder to compare results directly.

This review only looked at full marathons, not half-marathons or ultra-marathons, so the findings don't necessarily apply to those distances.

This is a summary of research, not medical advice. Talk to your own healthcare provider about anything affecting your care.

This meta-analysis synthesized 13 pre-post studies (n=824) examining hs-cTnI and hs-cTnT changes surrounding marathon completion, using a before-after quality assessment tool given the absence of control groups. Pooled results showed statistically significant post-race elevations in both hs-cTnI (MD 68.79 ng/L, 95% CI 53.22 to 84.37) and hs-cTnT (MD 42.91 ng/L, 95% CI 30.39 to 55.43). Notably, hs-cTnT levels normalized by 72 to 96 hours post-race (MD 0.11 ng/L, 95% CI -1.30 to 1.52, p=0.88), supporting a transient rather than sustained myocardial response.

Subgroup analysis identified the 99th percentile upper reference limit as a likely contributor to between-study heterogeneity, indicating inconsistent assay thresholds across the included studies. The authors interpret these findings as evidence against irreversible myocardial injury from marathon running, though the review is limited to full marathon distances and does not extend to half or ultra-marathons. As a pre-post design meta-analysis without control comparisons, causal inference about long-term cardiac consequences remains constrained, and the heterogeneity in reference standards warrants caution when comparing across studies.