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Marathon vs Half Marathon; New Study Reveals Which Race Hits Your Heart Harder

Written by 
Matteo Sargenti

Published on March 6, 2026

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Marathon or half marathon: new heart scans from the 2023 Silesia Marathon suggest both distances cause only small, short-lived dips in heart performance for most recreational runners, with readings returning to normal within two weeks.

Marathon vs Half Marathon; New Study Reveals Which Race Hits Your Heart Harder

​A new study suggests that running a marathon may not be significantly harder on the heart than running a half marathon, at least for most recreational runners.

​Researchers analyzed 105 runners who took part in the 2023 Silesia Marathon.

​The participants were divided into two groups: 49 runners who completed the half marathon and 56 who ran either the full marathon or an ultramarathon.

​To understand how racing affects the heart, scientists performed heart ultrasounds and advanced imaging tests at three different times: several days before the race, immediately after finishing, and again two weeks later.

​The results showed small changes in heart function right after the race in both groups.

​The heart’s main pumping chamber, known as the left ventricle, showed a slight drop in performance after runners crossed the finish line. However, the values remained within the normal range and returned to baseline during the two-week follow-up.

​The pattern of cardiac fatigue looked similar for both half marathon and longer-distance runners.

​Importantly, most of the changes were mild and temporary. Within two weeks, heart function had returned to normal for nearly all participants.

​Researchers say the findings reinforce an important message for endurance athletes: long races can temporarily stress the heart, but for healthy runners this response appears to be part of normal recovery rather than lasting damage.

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