Intermittent fasting associated with aerobic exercise improves oxidative parameters and causes muscle damage without compromising the performance of Wistar rats

•Intermittent fasting and exercise reduced body weight and lean mass.•Intermittent fasting did not change physical performance during aerobic exercise.•Intermittent fasting combined with aerobic exercise decreased homeostatic model assessment for insulin resistance, low-density lipoprotein, lactate dehydrogenase, and metabolic index.•Intermittent fasting and exercise increased total antioxidant capacity in soleus and in extensor digitorum longus muscles.•Intermittent fasting and exercise caused muscle fiber damage, with increase in the positivity marking for tumor necrosis factor-α. The aim of this study was to` investigate the effects of intermittent fasting (IF) and the possible association with aerobic exercise on performance, oxidative, biochemical, and somatic parameters of Wistar rats. Forty rats were randomized into the following groups: sedentary (SC) and trained (TC) controls, sedentary intermittent fasting (SIF), and trained intermittent fasting (TIF). The rats were subjected to IF for 15 h every day and aerobic exercise lasting 30 min, five times a week, at a speed of 15 m/min for 4 wk. Performance tests were performed at the beginning and end of the protocol. Glucose and insulin tolerance, somatic parameters, lipidogram, leptin, insulin, malondialdehyde, antioxidant capacity, C-reactive protein, alpha acid glycoprotein, creatine kinase, lactate dehydrogenase, and muscle histology were analyzed. The trained groups had similar performance and significantly improved performance at the end of the experiment. TIF showed lower body weight (–16 g), lean mass (22.49%), homeostatic model assessment for insulin resistance (29%), and lactate dehydrogenase (48%), and higher malondialdehyde (53%) and antioxidant capacity (75%) than the TC group. The SIF and TIF groups showed a fiber area reduction and positivity marking for tumor necrosis factor-α in the muscles. Although IF associated with aerobic exercise improved antioxidant capacity caused damage to muscle fibers and lean mass loss, it did not change the performance of the rats. [Display omitted]