Review explores impact of extreme endurance running on heart health

Adjustments to the guts linked to marathon working fluctuate by age, intercourse, and coaching stage, finds a synthesis of the accessible knowledge, revealed within the open entry journal BMJ Open Sport & Train Medication.

Nevertheless it’s not clear if these adjustments signify regular physiological responses to endurance train or whether or not they’re long run (mal)diversifications, the findings point out.

It is identified that each low and intensely excessive ranges of train could improve the chance of loss of life, word the researchers. And endurance train induces acute adjustments in coronary heart operate and will increase in substances, corresponding to enzymes and proteins, indicative of tissue injury and irritation, they add.

However whether or not these adjustments are regular transient physiological responses to the additional calls for placed on the guts beneath these circumstances or early indicators of doubtless dangerous long run diversifications is not clear, they level out.

To shed additional mild on the difficulty, the researchers scoured analysis databases for related research, revealed in English as much as April 2025, every of which in contrast the consequences of marathon working on the guts earlier than and after the occasion.

The researchers seemed specifically at 3 biomarkers indicative of coronary heart wall stress or injury to the myocardium, the center layer of the guts wall; ultrasound scan outcomes of the guts’s construction, valves, and pumping chambers (echocardiography); and cardiac MRI findings. 

The three biomarkers have been: cardiac troponin T(cTnT); cardiac troponin I (cTnI); and N-terminal proB-type natriuretic peptide (NT-proBNP).

Some 69 research, comprising 3274 principally male (73%) members between the ages of 27 and 63, have been eligible for systematic assessment, and 49 have been included within the pooled knowledge evaluation.

The evaluation confirmed that each one 3 biomarkers have been persistently raised inside the first hour after ending a marathon, exceeding generally used medical thresholds for myocardial damage, restricted blood provide (ischemia), or coronary heart failure.

Varied adjustments to the chamber quantity and pumping dynamics of the guts additionally occurred after working a marathon, together with the left ventricular ejection fraction, a measure of the quantity of blood pumped out of the guts’s major pumping chamber (the left ventricle) with every beat.

However these adjustments have been minor and fell exterior the vary of what would generally be interpreted as clinically significant, say the researchers.

There have been no different evident MRI adjustments to any of the opposite capabilities measured, suggesting marathon working does not induce any seen indicators of clinically related structural myocardial damage, say the researchers.

Biomarker adjustments and echocardiography findings different by efficiency working occasions, age, intercourse, and coaching stage.

The researchers acknowledge numerous limitations to their findings. Notably, a lot of the examine members have been males, and ladies may need totally different cardiovascular responses to marathon working, each within the quick and long run, they are saying. What’s extra, coaching standing, a probably influential issue, wasn’t persistently reported throughout the included research both.

And most of the research included within the assessment scored excessive on the chance of bias, indicating room for methodological enchancment, they add.

“Our pooled findings affirm and quantify beforehand reported post-marathon elevations in cardiac biomarkers and alterations in ventricular operate. Nevertheless, the medical relevance of those adjustments stays unclear,” level out the researchers. 

“The potential for pathological penalties in inclined people or with repeated participation in excessive endurance occasions stays,” they add.

Properly designed long run research in numerous teams, to incorporate intercourse and ethnicity, are wanted to seek out out “whether or not these results signify physiological responses to excessive ranges of train or mirror early markers of pathological cardiac transforming,” they conclude.