Intensive endurance sports can damage hearts
Sport keeps people healthy. A scientific study by the University Medical Center Hamburg-Eppendorf showed that our heart is badly damaged if the performance limit is constantly exceeded. Men are particularly affected.
Constantly intense exercise can be unhealthy
Athletes, pay attention: too intensive sports can be unhealthy! As a group of researchers from the University Medical Center Hamburg-Eppendorf (UKE) reports in the science magazine JACC: Cardiovascular Imaging, male triathletes may risk their heart health if they put too much strain on them in competition. The researchers were unable to identify such negative effects in female triathletes.
"We have indications that the scarring of the heart muscle observed exclusively in male study participants has to do with the amount of competition. The greater the load, the longer the distances covered in the competition, the higher the likelihood of damage to the heart muscle, ”explains the head of the working group, Prof. Dr. Gunnar Lund from the UKE Clinic and Polyclinic for Diagnostic and Interventional Radiology and Nuclear Medicine. “There is probably a personal stress limit. If it is exceeded, the heart can be damaged. "
Obviously healthy athletes with scarring on the heart muscle
As part of a scientific study, the UKE team examined 54 male and 29 female triathletes - all ambitious and healthy recreational athletes who train at least ten hours a week and are an average of 43 years old (plus / minus ten years). The doctors examined the triathletes after the administration of contrast media with cardio-magnetic resonance tomography (MRT). The result: contrast medium accumulations were found in the muscle of the left ventricle in ten male participants who had previously covered long distances by swimming and / or by bike. "The contrast medium shows scarring of the heart muscle, so-called myocardial fibrosis, which can be associated with the occurrence of life-threatening cardiac arrhythmias," explains Prof. Lund.
An existing and previously unrecognized myocarditis can be a possible cause of the scarring found: "In the normal population, myocarditis occurs with a frequency of three to four percent. In contrast, 17 percent of our male study participants are affected, so that there must be other causes. ”It is conceivable that the heart is overloaded by too much exercise at the performance limit. The sufferers had an increased myocardial muscle mass and sometimes high blood pressure under stress, which may have favored the heart muscle damage.
Prof. Lund: "Similar to a poorly adjusted engine that constantly runs at high revs, the heart can damage itself in the long run." The male hormone testosterone could also play a role. “That would explain why we didn't find any fibrotic changes in the heart muscle in women. But maybe women are inherently better protected for another reason - or they are just smarter and don't spend as much as men. ”
According to the doctor, recreational athletes do not have to worry: "At a moderate level, sports are undoubtedly healthy and prolong life." Those who put themselves under heavy or very heavy loads should have their heart examined at least once, according to Prof. Lund. “Best with a cardio-MRI like the one we used. This is the only technique that can be used to detect scarring of the heart muscles in athletes. An ultrasound examination or an EKG is not enough. ”(Sb, pm)
Tahir, E. et al Myocardial Fibrosis in Competitive Triathletes Detected by Contrast-Enhanced CMR Correlates With Exercise-Induced Hypertension and Competition History. JACC: Cardiovascular Imag-ing, 2017. DOI: 10.1016 / j.jcmg.2017.09.016