Atrial fibrillation (AF) confers a 1.5- to 2.0-fold increased risk of all-cause mortality and morbidity1,2. Its global incidence and prevalence continue to rise, with ∼50 million people projected to be affected by 20303,4. AF also drives heavy health care utilization3,5. In Europe, the median annual cost per patient is €3,930 (US$ PPPs 5,622) versus €38,256 (US$ PPPs 40,717) in the United States6. Modifiable lifestyle factors such as physical inactivity, obesity, alcohol consumption, and smoking substantially contribute to AF onset and progression, underscoring the need for preventive strategies7, 8, 9.

Pulmonary vein isolation (PVI) is a type of ablation that is currently considered the primary treatment for AF, with 60%-80% success10,11, defined as freedom from AF beyond the 60-day post-procedural blanking period (BP), during which early AF recurrences are not considered treatment failure12. This procedure is safe and more effective than antiarrhythmic drugs in reducing arrhythmic load and can be performed using radiofrequency13, cryoablation, or, more recently, pulsed-field ablation14, 15, 16.

The current European Society of Cardiology (ESC), American College of Cardiology (ACC), and American Heart Association (AHA) guidelines recognize moderate-intensity exercise, excluding athletes, as an effective adjunct to reduce symptoms and AF burden and to improve functional capacity and quality of life9,17,18. A recent systematic review of exercise-based cardiac rehabilitation following PVI reported beneficial effects on AF burden, physical fitness, and adverse event rates19. However, most trials inadequately describe the exercise intervention and fail to report essential information20. Moreover, no studies have specifically addressed the return to physical exercise after PVI, and there are no clear recommendations21. Moreover, many published programs require specialized equipment, extensive materials, and spacious facilities, limiting their implementation17, 18, 19. Therefore, there is a need for shorter, simpler interventions that can be implemented in both hospital and outpatient settings, maintaining participant motivation without the burden of complex logistical demands.

Endurance training is the traditional cornerstone of cardiac rehabilitation owing to its well-established physiological adaptations22,23, and moderate-intensity continuous training (MICT) is considered safe and effective for reducing AF risk and secondary cardiovascular events24. Resistance training also improves muscular strength and function while favorably modifying cardiovascular risk factors25,26. Combining endurance and resistance training, referred to as concurrent training (CT), often produces greater overall benefits than either alone across different populations25. Accordingly, we propose a CT intervention that can be conducted in a simple setting to assess its effect on patients and to establish exercise recommendations after PVI that can be safely performed outside the hospital environment, with support from a sports scientist or even autonomously.

AF symptoms, before PVI, often result in less active lifestyles, which negatively impact patients’ health7,27. Even several months after PVI, many patients do not return to active lifestyles and exercise practice for fear of AF recurrence. Nevertheless, one month after PVI, the patient can return to sports if there is no recurrence of AF21. However, it is not known whether this could result in AF recurrence in the future. Thus, no firm recommendation can be made on the “safe” dose of sport after PVI21.

Endurance training improves cardiovascular function and can also reduce the burden of AF in patients with recurrent AF17,28. The 2018 Physical Activity Guidelines Advisory Committee Report recommends 150 minutes/week of moderate-intensity endurance exercise for all adults to improve cardiovascular health29. In people with AF or other cardiovascular diseases, similar cardiovascular adaptations are achieved through moderate and vigorous physical exercise17,30. The American College of Sports Medicine (ACSM) proposes a range of 64-76% of maximum heart rate (HRmax) as moderate intensity31. Given a heterogeneous sample of men and women of different ages and physical conditions, HRmax will be calculated using the equation of Gellish et al32. The ACSM suggests at least 3 days/week for this kind of training and a session duration that may progress from 20 to 60 minutes of endurance work34, in addition to resistance training, consistent with clinical trials in patients after PVI similar to our protocol33,34.

Resistance training improves cardiometabolic risk profiles and reduces cardiovascular disease25,31. At least two resistance days per week and at least one set of 8-12 repetitions (4-6 repetitions in reserve; RIR) per exercise (8-10 different exercises involving major muscle groups) are necessary to find muscle adaptations25,28,35. For untrained individuals, current literature shows that large muscle strength gains can be achieved with short (<60s) and moderate (60-120s) rest intervals between sets36.

In this regard, combining both exercise types (CT) produces greater positive effects than performing them separately25. For this reason, a 12-week CT intervention is proposed, in which the first 4 weeks will progressively increase the volume to meet the WHO minimum physical activity recommendations, i.e., 150 min of moderate PA and 2 resistance days, during the last 8 weeks19,37.

The purpose of this study is to evaluate how a CT intervention impacts AF burden, cardiac structure and electrical activity, physical fitness, PA levels, body composition, and health-related quality of life (HRQoL) in patients who have undergone PVI.