Why is exercise protective?
Garnvik emphasizes that the study can’t guarantee that physical activity is actually the factor that protects against atrial fibrillation. However, the analysis takes into account several other factors that could potentially explain the link. These factors include smoking, alcohol use and previous cardiovascular disease. Garnvik also provides several possible explanations as to why exercise can counteract atrial fibrillation in obese people.
“Physical activity and exercise reduce a lot of the known risk factors for atrial fibrillation, like high blood pressure, high blood sugar, high cholesterol and chronic inflammation. Physical activity can also improve a person’s fitness level, and we know that people in good shape have a reduced risk of heart failure,” says the PhD candidate.
More than 43,000 participants
The study is based on information from 43,602 men and women who participated in the Nord-Trøndelag Health Study (the HUNT Study) between 2006 and 2008. Nearly 1500 of them developed atrial fibrillation by the end of 2015. “One strength of our study is that doctors confirmed the participants’ atrial fibrillation diagnosis, and unlike many previous studies, we didn’t solely rely on the participants themselves telling us they had the condition,” says Garnvik.
Several well-known athletes have had episodes of atrial fibrillation, and some have suggested that exercise can increase the risk. But that’s a qualified truth, Garnvik said. “Athletes and others who’ve built up a lot of stamina over many years may have an increased risk of atrial fibrillation. But both our study and many others show thatphysical activity is healthy in the amounts that are relevant for most people. This is also true when we talk about the danger of atrial fibrillation,” he says.
Garnvik’s study has been published in the journalEuropean Journal of Preventive Cardiology:Physical activity modifies the risk of atrial fibrillation in obese individuals: The HUNT3 study