“Time in atrial fibrillation and symptoms of the disease were reduced, and exercise capacity, cardiac function, lipid levels and quality of life were improved in the patients preforming high intensity interval training”, PhD candidate at CERG and medical doctor at St. Olavs Hospital, Vegard Malmo.
He is first author in the paper “Aerobic Interval training reduces the burden of atrial fibrillation in the short term: A randomized trial” recently published in Circulation. In this study, 51 persons with non-permanent atrial fibrillation (AF) were randomized either to high intensity interval training (four 4-minute intervals at 85-95% of peak heart) rate three times a week for 12 weeks or a control group (continuing their earlier exercise habits). Minutes of AF each day was monitored continuously with an implanted recorder. In addition cardiac function, exercise capacity, lipid status, quality of life and AF symptoms were assessed.
To the question regarding the most unexpected findings of the current study, the last author and a Medical doctor and researcher Jan Pål Loennechen, replied in Open Heart, the official blog of Circulation, an American Heart Association Journal:
“It was surprising that many of the patients had substantial effect on AF burden after a relatively short period of time with exercise. Some of the positive effects are thought to be mediated through reduction of risk factors like hypertension and overweight.”
Exercise resulted in significant improvements compared to controls. Sixteen persons in the control group had an increase in time in AF, in contrast to only three persons in the exercise group and the increase was more pronounced in the control group.
Five persons in the control group and 10 persons in the exercise group had a decreased time in AF, with the largest changes in the exercise group. The exercise group had a reduction of mean time in AF, from 8.1 percent to 5.8 percent, while mean time in AF increased from 10.4 percent to 14.6 percent in the control group. In addition, AF symptoms were reduced, and exercise capacity, cardiac function, lipid levels and quality of life were improved in the exercise group.
This is a small study in a relatively healthy population, so further studies are needed to explore the effect of exercise in other, more diverse, AF populations and over a longer period of time. The findings are, however, supported by multiple other recent studies.
“Overall, the study supports the concept that interventions aimed at lifestyle and risk factors should be central in the management and prevention of AF,” Malmo said to Medscape.
Vegard Malmo, PhD candidate at CERG