Is football your kids' favourite sport? Beware, playing football regularly may cause structural changes in the heart and elevate the risk of heart rhythm disorders later in life, researchers have warned.The study found that people who play football have a 5.5 times higher likelihood of developing atrial fibrillation, including other signs of abnormal electrical impulses in the heart, compared to the non-athletes.Atrial fibrillation is known to cause heart palpitations, dizziness and chest pain and increases the risk of stroke, heart attack and heart failure. "We know that sporting activity increases longevity and has multiple benefits for the cardiovascular system, but our findings seem to suggest that perhaps when you get to the extreme ends that we see in these elite athletes, there may be a negative impact on the heart," said lead author Dermot Phelan, doctoral student at Cleveland Clinic in Ohio, US."Players should not assume that leading a healthy lifestyle in terms of regular exercise means that they're immune from developing cardiac problems and, in fact, they may be at higher risk for things like atrial fibrillation," Phelan added.For the study, to be presented in the American College of Cardiology's 67th Annual Scientific Session 2018 in Orlando, the team conducted a cardiovascular screening of 460 former National Football League (NFL) players.They compared the results to a sample of 925 people from the general public with similar demographics to the NFL cohort in terms of age and race.The football players also tended to have a lower resting heart rate than their non-athlete counterparts, which is usually indicative of cardiovascular health but in the athletes' cases, this may have masked the symptoms of atrial fibrillation.The findings underscored the need for football players of all ages to get regular medical checkups to identify any early signs of cardiovascular disease.