TNF and atrial fibrillation: High-intensity and long-term physical training resulted in increased leukocyte output and pro-inflammatory cytokine (TNF-α, IL-2, IL-6 and IL-8) release (Santos et al., 2007; Kawanishi et al., 2015; de Barcellos et al., 2021), along with a greater susceptibility to AF (Guasch et al., 2013; Aschar-Sobbi et al., 2015).