High-sensitivity cardiac troponin T release after a single bout of high-intensity interval exercise in experienced marathon runners.
Level 4 - case-series / case-control
Single-arm uncontrolled pre-post interventional trial
PubMed 29541132 · doi:10.1016/j.jesf.2017.08.001
What was done
Twenty-one experienced marathon runners completed a single treadmill high-intensity interval exercise session. The protocol comprised 23 cycles (92 minutes total) alternating between 2 minutes of hard running at 90% vVO2max (15.8 ± 1.3 km/h) and 2 minutes of active recovery at 50% vVO2max (8.8 ± 0.7 km/h). Heart rate was recorded every 2 minutes. Serum high-sensitivity cardiac troponin T (hs-cTnT) was measured before exercise, immediately post-exercise (0 h), and at 4 and 24 hours post-exercise.
What was found
Hs-cTnT concentrations increased immediately post-exercise, peaked at 4 hours, and remained elevated above baseline at 24 hours. The 4-hour hs-cTnT response was positively correlated with exercise heart rate, such that runners with higher heart rates under the fixed relative intensity demonstrated greater biomarker release. The abstract does not provide exact numerical values, effect sizes, confidence intervals, or p-values for hs-cTnT levels or correlation statistics.
Why it matters
The study shows that interval running can stimulate acute cardiac troponin T release in trained endurance runners and suggests exercise heart rate may partly account for individual variability in post-exercise troponin kinetics.
Limits
The study had a small sample size (n = 21) restricted solely to experienced marathon runners, limiting generalizability to other populations. It lacked a non-exercise control group or a continuous exercise comparator matched for energy expenditure. The abstract provides no exact quantitative concentrations, participant demographic breakdowns, or clinical follow-up regarding the physiological significance of the elevation.
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