Download our Free 8-Week Plan here →

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

May 19, 2026

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.

​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.

Join The Conversation

You Might Also Like

10 Ways That Running Improves Your Mental Health

Discover 10 science-backed ways running improves your mental health, from lower stress and better sleep to stronger self-belief, sharper thinking, and real resilience.

The Best Sleep Position for Runners Who Want to Wake Up Fully Recovered

Discover the best sleep position for runners, why side and back sleeping beat stomach sleeping, and simple tweaks to wake up fresher after hard training.

Returning to Running Training After an Injury

Get back to running after injury without setbacks. Learn when you’re truly ready, how to restart with short easy runs, build up gradually, use low-impact training, and spot warning signs before pain turns into reinjury.

6 Common Running Injuries and How to Avoid Them

Learn how to spot and prevent the six most common running injuries from runner’s knee and shin splints to plantar fasciitis and IT band pain by managing training load, improving strength and form, and prioritizing recovery.

15 Best Supplements for Runners (What Actually Helps Performance and Recovery)

Supplements can help runners chase small gains, but most don’t need many. This guide cuts through the hype with evidence-backed picks for pre-run energy, long-run fueling, and faster recovery without replacing the fundamentals.

The 99-Year-Old Who Still Works Out and What Her Routine Can Teach Us

Meet the 99-year-old woman quietly rewriting what aging “should” look like by sticking to simple strength training, daily walking, and mobility work that keeps her strong, steady, and fiercely independent.