Blood markers suggest heart damage in amateur marathoners

04 Dec, 2018 11:02 am

MADRID (Reuters ) – Some of the same blood markers that spike following a heart attack also skyrocket in amateur long-distance runners, especially those who do a full marathon, researchers say.

The small study in Spain tested non-professional runners before and after 10K, half-marathon and full-marathon races and found that a protein called troponin, which indicates damage to the heart muscle, surges to many times its normal level after a full marathon. It’s not clear if this represents long-term damage, however, the study team writes in the journal Circulation.

“The main conclusion is that cardiac stress during a marathon is higher than the cardiac stress produced by competing in shorter-distance events, at least in athletes with low experience and low training background,” the study’s senior author Juan Del Coso, director of the exercise physiology laboratory at Camilo Jose Cela University in Madrid, told Reuters Health in an email.

The new study grew out of previous work that looked at the impact of endurance events on other muscles in the bodies of amateurs who are not able to train as hard as professionals prior to competitions, Del Coso said.

“We have found a relationship between the lack of training and high levels of muscle damage and we started to believe this ‘damage’ in skeletal muscle could also happen in the (heart’s muscle fibers),” Del Coso said. “If we look at the practical applications of our investigation, (this suggests) potential marathon runners should prepare the race with a professional coach, decide to compete in the race after an adequate training background and with planned nutrition and hydration strategies.”

Del Coso and his colleagues measured several biomarkers in the blood of 63 volunteers, whose mean age was 37, before races and again 10 minutes after the competitions were finished. Two types of biomarkers showed small increases, but cardiac troponins rose dramatically with increasing race distance.

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