Athletes more likely to have irregular heartbeats than non-athletes – study Joggers run around Clifton Downs, Bristol (Ben Birchall/PA) Athletes are two and half times more likely than non-athletes to experience irregular heartbeats, studies suggest. Researchers analysed 13 studies between 1990 and December 2020 which examined the health of athletes who took part in sports including cycling, running, swimming, Nordic skiing, orienteering, rowing, football, rugby and netball. The studies included data on 70,478 participants. Previous studies have shown that physical activity can improve cardiovascular health and is associated with reduced illness and deaths. However the new research suggests there is a threshold beyond which exposure to increasing levels of exercise is linked to heart issues including atrial fibrillation – a condition that sees irregular heartbeats raise the risk of stroke, heart failure and other heart-related problems.