IJCS | Volume 32, Nº4, July/August 2019

388 Figure 2 - Risk of incidence of atrial fibrillation in individuals submitted to physical exercises. Garlipp et al. Physical activity and atrial fibrillation Int J Cardiovasc Sci. 2019;32(4):384-390 Original Article demonstrated improvements promoted by physical exercise in quality of life, in addition to the reduction of symptoms in patients with AF. According to Anderson and Taylor, 26 physical capacity is the main clinical outcome of cardiac rehabilitation, regardless of diagnosis. For each increase of 1 Metabolic Equivalent (MET) in physical capacity, mortality rate decreases by 17% in men and 14% in women. Thus, physical exercise seems safe for patients with AF besides triggering several benefits. 27 Another important factor is the strong relationship between obesity and AF. According to Pathak et al., 28 electrical factors and structural remodeling caused by obesity lead to the genesis and perpetuation of AF. In this sense, physical exercise, in addition to assisting inweight loss and consequent reduction in AF recurrence, 5,29 may protect against AF even in the presence of obesity. 30 The study by Pathack et al., 31 showed that an increase in cardiorespiratory fitness around 2METswas associated with reduced density of AF. According to Abed et al., 32 decrease in AF density due to exercise can be explained by increased cardiorespiratory capacity and weight loss. Increase in each metabolic equivalent (MET) results in a 20% decrease in the risk of recurrence of AF. 32 Skielboe et al., 33 in order to verify if high-intensity exercises were more effective in decreasingAF density than low-intensity exercises, did not identify differences. However, it has the effects of training on the functional capacity of individuals with AF, Luo et al., 20 submitted patients with AF and patients after myocardial infarctionwith reduced ejection fraction to supervised training with aerobic exercises, three times a week for 36 sessions, thenmoving on to a home program for another two years. The training was efficient, resulting in increased cardiorespiratory capacity and peak VO 2 in both groups, but no significant differences were identified between the groups. The international guidelines recommend the practice of physical activity in patients with AF in order to reduce their comorbidities. 21 When Malmo et al., 22 submitted 26 AF patients to interval aerobic training, demonstrated that 12 weeks were enough to decrease arrhythmic load, besides causing a decrease in the symptoms related toAF. In addition, improvement in maximum work capacity, atrial and left ventricular function, lipid levels and quality of life were identified. For Osbak et al., 3 patients with heart disease lose muscle mass and strength due to inactivity and local hemodynamic changes. This way, developing strategies that allow the increase of muscle strength in these patients becomes important in order to increase mobility, posture and balance. In an observational study of 20,000 adults, Proietti et al. 23 observed lower all-cause mortality in AF patients who reported being involved with regular physical activity. Still, Hegbom et al., 24 and Plisiene et al., 25