SOD1 and congestive heart failure: Thus, this study aimed to compare the effects of three exercise situations of different intensities and durations on the levels of the inflammatory markers sTNFR1 (soluble tumor necrosis factor receptor) and IL-6, and on oxidative stress, as assessed by plasma malondialdehyde (MDA) concentrations, as well as the activity of the antioxidant enzymes catalase (CAT) and superoxide dismutase (SOD), in individuals with CHF.