Strenuous exercise, whether performed by elite athletes or competitive weekend warriors, comes with a risk of developing cardiac disorders, including atrial fibrillation, researchers cautioned.
Among people who exercise four hours or more during the week, there was about a 39% increased risk of developing atrial fibrillation that required medical treatment, said Knut Gjesdal, MD, of the University of Oslo, Norway.
And among elite cross-country endurance skiers, the risk of developing arrhythmias increased by 37% when compared with athletes in the same race that skied at a more moderate pace, said Kasper Andersen, MD, of Uppsala University in Uppsala, Sweden.
In their presentations at the European Society of Cardiology, the researchers agreed that exercise does more good than harm, but doctors and participants still have to be aware that competitive sporting activities may have negative side effects. […]
Gjesdal’s group determined that there was an exercise-dose dependent increase in the risk of atrial fibrillation among men, but not among women. After multivariate analysis adjusted for age, height, body mass index, and education level, the hazard ratio for atrial fibrillation was 1.18 (CI 1.00, 1.40) for men in the moderate activities category.
For men in the intermediate activities group, the HR was 1.39 (CI 1,16, 1,67). The HR for men in the intensive activities group was 2.75 (2,10, 3,60). […]
Andersen’s group determined that skiers who finished with the best times — 100% to 160% of the winning time — were at greater risk of abnormal heart rhythms than those skiers who finished at a more leisurely pace of 241% of the winning time (HR 0.73, CI 0.58 to 0.92). The more elite skiers had a 37% risk of developing rhythm disturbances, Andersen said.
Based on a secondary analyses, a higher risk of ventricular arrhythmias/cardiac arrest was noted in those athletes who ran five or more races annually versus one race a year (HR 2.98, CI 1.31 to 6.78). There was a 29% greater risk of atrial fibrillation if a person had completed seven or more of the yearly races, Andersen said.
“Basically, this study shows that even though physical activity is generally healthy, athletes committed to endurance sports at elite level have higher risk of suffering from a heart rhythm disorder,” he said.
Don’t perform intense “cardio” exercise, like distance running. It could kill you.