Light activity may reduce stroke and death risk in atrial fibrillation

A large Norwegian study suggests that even modest physical activity may help reduce the risk of stroke and premature death in people with atrial fibrillation, challenging the idea that meaningful cardiovascular protection requires intense exercise. Researchers analyzed health data from more than 87,000 adults and found that people reporting low, moderate or high levels of regular activity had lower risks of stroke and death than those who were inactive. The association was observed in participants both with and without atrial fibrillation, an irregular heart rhythm that affects the upper chambers of the heart.

The findings, published Aug. 5, 2026, in the Journal of the American Heart Association, indicate that physical activity may offer broadly similar benefits across people with different heart-rhythm profiles. Compared with inactive adults, those in the low-activity group had a 9% lower risk of stroke, while moderate and highly active participants had 19% and 18% lower risks, respectively. The pattern was similar for death from any cause: low activity was associated with an 11% lower risk, moderate activity with an 18% lower risk and high activity with a 22% lower risk.

Atrial fibrillation, commonly called AFib, occurs when the heart’s atria beat irregularly and often rapidly rather than following a coordinated rhythm. The disorganized contractions can allow blood to pool in the heart, increasing the chance that a clot will form and travel to the brain. AFib is therefore a major risk factor for ischemic stroke, the most common type of stroke, which occurs when a clot blocks blood flow through an artery supplying the brain. The condition is also associated with heart failure and other cardiovascular complications.

“In general, people with AFib appear to be less active than the general population,” said lead author Kristoffer Johansen, Ph.D., a researcher at UiT The Arctic University of Norway. “The results from our study indicate that physical activity was associated with a reduced risk of stroke and death in individuals with and without atrial fibrillation.” The researchers said the results support regular movement as a potentially important preventive strategy for people with AFib, while emphasizing that the study shows an association rather than proving that exercise directly caused the reduction in risk.

The analysis drew on two major Norwegian population studies: the HUNT Study and the Tromsø Study. Participants had an average age of about 51 years when they enrolled, approximately 47% were men and more than 6,500 had AFib. Researchers linked survey responses about exercise with national health registries that recorded diagnoses of atrial fibrillation, stroke and death over roughly 15 years. Participants were classified according to how frequently they exercised, how long they exercised and how hard they pushed themselves, ranging from taking it easy without sweating or losing breath to exercising near exhaustion.

The study’s statistical design allowed participants who developed AFib during follow-up to be reclassified into the AFib group. This multiple-records approach was intended to create a more accurate comparison between people with and without the condition over time. Among participants with AFib, the researchers estimated that remaining active was associated with an average gain of approximately 0.5 to 1.2 years of life compared with being inactive. The greatest apparent benefit occurred among the most active participants, although the results also suggested that smaller amounts of activity were linked to better outcomes.

The biological explanation may involve several pathways. Regular movement can improve blood pressure, insulin sensitivity, body composition and vascular function, all of which influence stroke risk. Exercise may also improve cardiorespiratory fitness and reduce inflammation, while helping control conditions such as obesity, diabetes and sleep apnea that are linked to AFib. Physical activity can affect the autonomic nervous system and cardiac remodeling as well, although the ideal amount and intensity of exercise may differ among individuals with arrhythmias. For that reason, people with AFib should discuss safe activity levels with a health professional, particularly if they have symptoms or other heart disease.

Mina Chung, M.D., FAHA, who was not identified as an author of the study, said the findings add important evidence connecting physical activity with lower risks of stroke and death in people with and without AFib. She cautioned that activity may also serve as a marker of overall health: people who exercise more may be less likely to smoke, may have better access to health care or may be more able to manage chronic disease. The researchers adjusted for several factors, but they could not eliminate the possibility that unmeasured differences helped explain the results. Participants also reported their own activity, which means their estimates may not have precisely reflected actual exercise.

The American Heart Association recommends that adults spend less time sitting and aim for at least 150 minutes of moderate-intensity aerobic activity or 75 minutes of vigorous activity each week, alongside muscle-strengthening exercise at least twice weekly. The Norwegian findings suggest that people who cannot immediately reach those targets may still benefit from starting with manageable movement. Walking, cycling, swimming or other activities that can be performed consistently may represent a practical first step. For people living with AFib, the message is not that exercise replaces prescribed treatment, including stroke-prevention medication when indicated, but that appropriate physical activity may complement medical care and support longer-term cardiovascular health.

News Publication Date: Aug. 5, 2026

Web References: https://www.heart.org/en/health-topics/atrial-fibrillation ; https://www.heart.org/en/healthy-living/exercise-and-physical-activity/fitness-basics/aha-recs-for-physical-activity-in-adults ; https://newsroom.heart.org/news/even-light-activity-may-lower-stroke-death-risk-in-people-with-atrial-fibrillation

References: Journal of the American Heart Association manuscript: https://www.ahajournals.org/doi/10.1161/JAHA.126.048812