MONDAY, Aug. 24, 2015 (HealthDay News) — Exercise appears to help control an irregular heartbeat known as atrial fibrillation in obese people, a new study finds.
According to Australian researchers,”cardiorespiratory fitness” reduced the risk that this potentially dangerous heartbeat will return by as much as 84 percent — even more than losing weight. 
Cardiorespiratory fitness refers to the ability of the heart and lungs to supply oxygen to the body during sustained physical activity.Moreover, lead researcher Dr. Prashanthan Sanders, director of the Center for Heart Rhythm Disorders at the University of Adelaide in Australia said,”This study adds to a growing body of evidence that aggressive risk factor management with increased physical activity should be an integral component of management of atrial fibrillation.”Atrial fibrillation, the most common abnormal heart rhythm, affects about 2.7 million Americans, according to the American Heart Association. Obesity and inactivity are risk factors for atrial fibrillation, which can lead to stroke, the researchers pointed out.
One expert cautioned that additional research is needed to confirm the findings. Also, patients should consult with their doctor before embarking on an exercise program.The report was published online Aug. 24 in the Journal of the American College of Cardiology.For the study, Sanders and colleagues assigned 308 patients with atrial fibrillation to one of three groups based on their level of fitness: low, adequate, or high fitness. All had a body mass index (BMI) of 27 or more, meaning they were overweight or obese.The groups were followed for about four years to see how their level of fitness affected the recurrence of the abnormal heartbeat. Patients were also offered a doctor-led weight loss and exercise program.After four years of follow-up, 84 percent in the high fitness group no longer had atrial fibrillation, compared with 76 percent in the adequate group and 17 percent in the low fitness group, the researchers found.
Sanders’ team also found that for every increase in “metabolic equivalent” — a measure of the amount of oxygen used at rest — the risk of atrial fibrillation recurrence was reduced 20 percent.Those with increases of two or more metabolic equivalents who also lost weight had especially dramatic declines in the likelihood of atrial fibrillation recurrence, the findings showed.
“Increased physical activity to gain cardiorespiratory fitness is associated with a reduction in atrial fibrillation burden and maintenance of a normal heart rhythm,” Sanders said.
