ISLAMABAD, Aug 25: Exercise appears to help control an irregular heartbeat known as atrial fibrillation in obese people, a new study finds. Australian researchers found that “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. “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,” said lead researcher Dr. Prashanthan Sanders, director of the Center for Heart Rhythm Disorders at the University of Adelaide in Australia. 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.