{"id":508672,"date":"2026-06-19T22:55:13","date_gmt":"2026-06-19T22:55:13","guid":{"rendered":"https:\/\/www.newsbeep.com\/ie\/508672\/"},"modified":"2026-06-19T22:55:13","modified_gmt":"2026-06-19T22:55:13","slug":"marathon-training-acutely-changes-your-heart-but-it-affects-peoples-tickers-differently","status":"publish","type":"post","link":"https:\/\/www.newsbeep.com\/ie\/508672\/","title":{"rendered":"Marathon training acutely changes your heart \u2013 but it affects people\u2019s tickers differently"},"content":{"rendered":"

Many studies have already explored whether regularly running longer distances, like marathons<\/a> and ultramarathons<\/a>, can cause a runner\u2019s heart to change<\/a>. But how exactly does this happen? According to a new academic report, published in Open Sport & Exercise Medicine<\/a>, the nature of these physiological adaptions varies according to several factors, including your gender, age and the amount of training that you do each week. <\/p>\n

Working on the basis that both very low and extremely high levels of exercise can increase people\u2019s risk of death, and that endurance-level training is known to cause acute changes to the heart, researchers sought to shed more light on whether these adaptations are a \u2018normal physiological response\u2019 to the demands placed on the organ by running long distances, or if they\u2019re \u2018(mal)adaptations\u2019 that should cause us more pause for thought. Here\u2019s what they found.<\/p>\n

What happens to your heart when you\u2019re a runner?<\/p>\n

From historical studies, we know that consistent and reasonably high levels of exercise, such as the training regimes and challenges taken on by marathon and ultramarathon runners, trigger significant changes in the athletes\u2019 hearts, altering the way that the body\u2019s engine functions. However, behind the alarming headlines that this fact can produce lies a much more nuanced story. <\/p>\n

Although it is an organ, the heart responds to regular exercise like a muscle, by getting bigger and stronger, improving its capacity to push oxygen-rich blood around the body. Both the atria (the two upper \u2018filling chambers\u2019, where blood arrives in the organ) and the ventricles (the two lower chambers, which pump oxygen-rich blood out around the body) can become significantly bigger. <\/p>\n

Arteries become more flexible to allow more blood flow during exercise. Additional coronary capillaries also develop, which increases the distribution of blood to your hardworking muscles. Amazingly, an endurance runner might end up with a heart that\u2019s up to 50% bigger than that of someone who does not engage in any sporting activity.<\/p>\n

What did the report find?<\/p>\n

The new survey collated evidence that was harvested during 69 previous studies involving 3,274 participants aged between 27 and 63.<\/p>\n

Analysing ultrasound scan results of subjects\u2019 heart structures (valves and pumping chambers) and cardiac MRI findings, researchers zeroed in on three biomarkers \u2013 cardiac troponin T(cTnT); cardiac troponin I (cTnI); and N-terminal proB-type natriuretic peptide (NT-proBNP) \u2013 which are indicative of heart wall stress or damage to the myocardium (the middle layer of the heart wall).<\/p>\n

The results revealed that, during the first hour after finishing a marathon, all three biomarkers were consistently raised, often exceeding commonly used clinical thresholds for myocardial injury, restricted blood supply (ischaemia) or heart failure. The way that the runners\u2019 hearts pumped, as well as the volumes of blood being pushed out with each beat of the left ventricle (the primary pumping chamber), was also seen to change in several ways.<\/p>\n

Interestingly, these changes varied noticeably according to each runner\u2019s individual marathon time, age, sex and the level of training that they commonly do.<\/p>\n

However, as alarming as all this might sound, these changes were considered minor and they fell outside the range of what doctors and scientists commonly consider as \u2018clinically meaningful\u2019.<\/p>\n

The researchers also acknowledged a number of limitations to their findings, most notably the fact that the majority of the study participants were male (73%) and one of the influential factors, training status, wasn\u2019t consistently reported across the studies used.<\/p>\n

\u2018Our pooled findings confirm and quantify previously reported post-marathon elevations in cardiac biomarkers and alterations in ventricular function,\u2019 said the researchers. \u2018However, the clinical relevance of these changes remains unclear.<\/p>\n

\u2018The potential for pathological consequences in susceptible individuals or with repeated participation in extreme endurance events remains,\u2019 they added, while urging the need for further long-term studies involving a better diversity of sex and ethnicity. That way, they can find out \u2018whether these effects represent physiological responses to extreme levels of exercise or reflect early markers of pathological cardiac remodelling\u2019.<\/p>\n

Should runners be worried?<\/p>\n

In a nutshell, no. This new report is a synthesis of pre-collected data that backs up some facts about changes to the size and performance of people\u2019s hearts when they run longer distances, but the main takeaway is that detailed new research is required, using more mixed subject groups, to see how these changes impact people according to their age, sex and training habits. <\/p>\n

While tragedies do occasionally occur during running events, the overarching evidence produced by detailed studies continues to support the fact that running is good for your heart<\/a> \u2013 and that includes marathon training \u2013 and certainly better for your all-round health than a sedentary lifestyle.<\/p>\n

As always, it\u2019s important to combine exercise with good diet<\/a> and to listen carefully to your body \u2013 if you notice symptoms that suggest you\u2019re putting too much strain on your ticker, such as sustained and elevated levels of fatigue or dramatic changes in heart rate<\/a>, make immediate changes to your training regime and consult a doctor. <\/p>\n","protected":false},"excerpt":{"rendered":"Many studies have already explored whether regularly running longer distances, like marathons and ultramarathons, can cause a runner\u2019s…\n","protected":false},"author":2,"featured_media":508673,"comment_status":"","ping_status":"","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[37],"tags":[1134,217229,1107,499,103,61,60,184510,1135,217228],"class_list":["post-508672","post","type-post","status-publish","format-standard","has-post-thumbnail","category-fitness","tag-content-type-default","tag-contentid-359783e4-f64c-4752-bbf7-5c43c9f04aea","tag-displaytype-standard-article","tag-fitness","tag-health","tag-ie","tag-ireland","tag-issyndicated-false","tag-locale-gb","tag-shorttitle-heres-how-marathon-training-changes-your-heart"],"_links":{"self":[{"href":"https:\/\/www.newsbeep.com\/ie\/wp-json\/wp\/v2\/posts\/508672","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.newsbeep.com\/ie\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.newsbeep.com\/ie\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.newsbeep.com\/ie\/wp-json\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/www.newsbeep.com\/ie\/wp-json\/wp\/v2\/comments?post=508672"}],"version-history":[{"count":0,"href":"https:\/\/www.newsbeep.com\/ie\/wp-json\/wp\/v2\/posts\/508672\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.newsbeep.com\/ie\/wp-json\/wp\/v2\/media\/508673"}],"wp:attachment":[{"href":"https:\/\/www.newsbeep.com\/ie\/wp-json\/wp\/v2\/media?parent=508672"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.newsbeep.com\/ie\/wp-json\/wp\/v2\/categories?post=508672"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.newsbeep.com\/ie\/wp-json\/wp\/v2\/tags?post=508672"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}