TUESDAY, Nov. 21, 2017 (HealthDay News) -- Men who compete in triathlons could be putting their hearts at risk, a new study contends.
The finding results from an examination of 55 male triathletes who averaged 44 years old, and 30 female triathletes, with an average age of 43. All participated in triathlons, which involve sequential endurance competitions of swimming, cycling and running.
The researchers found that 18 percent of the men had evidence of scarring of the heart, known as myocardial fibrosis. None of the women had signs of the condition.
Myocardial fibrosis usually affects the pumping chambers and can progress to heart failure.
"The clinical relevance of these scars is currently unclear [but] they might be a foundation for future heart failure and arrhythmia [irregular heartbeat]," the study's lead author, Dr. Jitka Starekova, said in a news release from the Radiological Society of North America.
The study was to be presented during the group's annual meeting, Nov. 26 to Dec. 1, in Chicago.
Though regular exercise has been proven good for the heart, previous studies have found myocardial fibrosis in elite athletes.
"Although we cannot prove the exact mechanism for the development of myocardial fibrosis in triathletes, increased systolic blood pressure during exercise, the amount and extent of race distances and unnoticed myocarditis could be co-factors in the genesis of the condition," Starekova said.
She's with the department for diagnostic and interventional radiology and nuclear medicine at the University Medical Center Hamburg-Eppendorf in Germany.
"In other words, repetition of any extreme athletic activity may not be beneficial for everyone," she explained.
Starekova and her colleagues plan long-term follow-up of the triathletes with myocardial fibrosis.
Experts note that research presented at meetings should be considered preliminary because it has not been subjected to the scrutiny given to research published in medical journals.
The American Heart Association offers exercise advice.