High- and moderate-intensity training are equipotent in abrogating myocardial inflammation in rats fed aWestern diet

Western diet (WD) activates inflammatory pathways in the myocardium, where jeopardizes contractile function. This study aimed to compare the anti-inflammatory effects of high-intensity interval training (HIIT) and moderate-intensity continuous training (MICT) in rats fed a WD. Methods: Wistar rats were assigned to the six groups: normal diet (ND)+HIIT, WD+HIIT, ND+MICT, WD+MICT, sedentary fed a ND or WD (SED+ND and SED+WD, respectively). HIIT and MICT were performed on a motorized treadmill, five consecutive days/week for 12 weeks. In these animals, visceral fat mass and myocardial expression of pro-inflammatory cytokines i.e. tumor necrosis factor-alpha (TNF-) and myeloperoxidase (MPO) were measured. Western blotting was performed to identify cardiac protein expression. Results: WD+SED significantly increased visceral fat mass compared with ND+SED. WD+SED significantly resulted in TNF- over-expression compared with ND+SED. There were no significant differences in MPO expression between WD+SED and ND+SED. In trained groups, visceral fat mass and TNF- expression were lower in WD+HIIT and WD+MICT compared with WD+SED, with similar effects between HIIT and MICT modes. MPO expression was significantly lower in ND+HIIT and ND+MICT compared with ND+SED, with similar effects between HIIT and MICT modes. Conclusion: WD co-existing with SED paves the way to a pro-inflammatory milieu in the heart. HIIT and MICT exert similar anti-inflammatory effects on the myocardium; therefore, aerobic training, regardless of modality or intensity, can be a practical solution for those who regularly consume WD.