The paper is authored by NEXAF PhD-candidate Kristoffer Robin Johansen and is based on data from The Birkebeiner Ageing Study and The Tromsø Study. Norwegian male cross-country (XC) skiers who had completed an average of 14 years of participation in the 54-kilometer Birkebeiner XC ski race and men of the same age representing a general Norwegian population were followed for approximaltely 10 years. Atrial fibrillation and stroke risk were estimated based on questionnaires. After the 10-year follow-up, almost 30% of the XC skiers had developed atrial fibrillation, corresponding to an almost twice as high risk of atrial fibrillation compared to the men from the general population.

While atrial fibrillation is known to be associated with an increased risk of stroke in general, the skiers had a relatively low risk of stroke (5% after the 10-year follow-up). The results from this study suggest that exercise-associated atrial fibrillation involves a lower risk of stroke compared to atrial fibrillation related to other risk factors. At the same time, skiers with atrial fibrillation had a twice as high risk of stroke than skiers without atrial fibrillation. The paper was published in the journal BMJ Open Heart.