How Fitness Trackers Can Help Reduce Afib and Stroke Risk

A new study from researchers at Massachusetts General Hospital shows that regular exercise can reduce your risk for both atrial fibrillation (afib) and stroke.

The research also highlighted the benefits of using wearable fitness trackers to get more accurate data about activity levels, as well as potentially monitoring conditions like afib.

The study, published in the European Heart Journal, followed over 93,000 participants from the United Kingdom who did not have a prior history of afib—an irregular heart rhythm caused by rapid electric impulses in the heart's atria.

The participants wore fitness tracking devices with heart rate monitoring capabilities for one week, which tracked how much physical activity they got.

When the researchers followed up on participants over five years, the people who got a minimum of 150 minutes of moderate activity during the week that they had tracked their activity were 18% less likely to develop afib or have a stroke.

In a press release, the study's lead author, Shaan Khurshid, MD, said that the findings "supported recommendations from the European Society of Cardiology, the American Heart Association, and the World Health Organization for 150 minutes or greater of moderate to vigorous physical activity per week."

Wearables Provide More Accurate Data

Another key finding of the study was that fitness trackers are more accurate at measuring physical activity than self-reporting. The research found that patient reports of their activity levels can be subjective and unreliable.

In the press release that accompanied the research, the study’s senior author Steven Lubitz, MD, MPH explained that while some studies that were done at the population level have shown a lower risk of afib in people who exercise, that link has "remained inconclusive in part because those studies relied on self-reporting by participants," which he says is "a less than exact science."

That's where fitness trackers can be useful—both for people trying to track their activity levels and researchers who want to study them. Lubitz said that wearables equipped with accelerometers "provide an objective and reproducible measure of physical activity."

Based on what they were able to observe in participants who wore fitness trackers, Lubitz said that the team found that "activity in accordance with guideline recommendations is indeed associated with substantially lower risks of both atrial fibrillation and stroke.”

Why Is Physical Activity Linked to Lower Afib Risk?

The researchers hope that the increasing popularity of wearable fitness devices will lead to an increase in the early detection, and perhaps prevention, of conditions like atrial fibrillation.

“This study has given us some data regarding the relationship between physical activity and the risk for stroke,” Pedram Kazemian, MD, a Deborah Heart and Lung Center cardiologist who specializes in heart rhythm disorders, tells Verywell. “Moving forward after this observation, we have to dig deep into the physiology and ask how physical activity reduces the risk of afib."

The team speculated that a reduction in blood sugar or blood pressure, both of which are tied to regular exercise, could lead to a lower risk of afib.

Accounting for Other Afib Risk Factors

While the study findings are promising, Kazemian says that people who exercise regularly are also more likely to be taking other proactive measures for their health.

“Patients who are more active are healthier overall and will have less chance of stroke and atrial fibrillation," says Kazemian. "They have lower weight, are less likely to be diabetic or have high blood pressure, and are more compliant with their medications."

While the study did account for some of these factors, some were missing. "Many unknown factors such as compliance with medication or unhealthy behaviors could potentially confound the results,” says Kazemian. “A patient could lose weight, decrease their blood pressure, or they may start or quit smoking. In five years, a lot of things can change.”

Benefits for Afib Patients

According to a recent survey conducted by patient advocacy organization StopAfib.org, patients who already use wearable devices to monitor their afib report feeling more comfortable knowing what their heart rate is at any given time.

Tracking can be particularly beneficial for people with afib that comes and goes (paroxysmal). The survey participants also reported that wearable fitness devices make it easier for them to share data with their doctors. Having that data also improves their doctor’s ability to provide appropriate care based on their condition.

Wearables for Afib

Afib must be diagnosed by a doctor based on a patient's EKG findings, but wearable fitness devices have the potential to identify the abnormal and rapid heart rate that accompanies afib before other symptoms, such as shortness of breath or feeling light-headed, appear.

Mellanie True Hills, former afib patient, afib awareness advocate, and the founder of StopAfib.org, tells Verywell that "anywhere from half to two-thirds of patients know when they are in afib, but the rest may not know."

Hills says that wearables have the potential to "help people identify that they may be having afib so they can get diagnosed sooner with an actual EKG."

Wearable fitness devices can also help people who already have afib, and their doctors, monitor the condition. "If they are tracking their afib, they can know if a procedure was successful or their medication is working,” she says.

Hills adds that for people who have afib, tracking physical activity is also important. "We have devices to tell us whether we're in afib and to track the amount of activity we're getting, so we can potentially correlate the two to tell what effect, if any, physical activity has on our afib."

Should You Get a Fitness Tracker?

A fitness tracker can be useful if you want to get a more accurate assessment of your physical activity and exercise levels. Kazemian says that he would encourage his patients to use a wearable fitness tracker. “They’re not that expensive, and objectively it says how many hours per week you engage in vigorous physical activity."

As a clinician, Kazemian says that having that objective data is important because many patients "actually overestimate the intensity and duration of their weekly activity."

Older people and those who are at high risk for conditions like afib can also benefit from wearable fitness tracking devices.

“Not only does afib cause strokes, but we also know that it also causes heart failure, dementia, and sudden cardiac arrest,” says Hills. “As people age, they’re much more susceptible to afib, so the watches may be even more valuable for screening for someone over the age of 50 than those under the age of 50, especially if they’ve had family members who’ve had afib or stroke.”

If you want to purchase a wearable fitness device to monitor for afib, Hills says to choose one that has been cleared by the Food and Drug Administration (FDA) for that purpose. Companies will place this information prominently on the product’s website and in their marketing materials. You can also search the FDA's medical devices database.