For a long time, endurance training was considered the main cause of oxidative stress, but it was clarified that free radicals can also be produced through other pathways, which are not necessarily related to the oxygen demand. Indeed, several studies have shown that even the anaerobic exercise (high intensity training, weight lifting, etc.) can produce similar levels of oxidative stress . Most of the studies regarding exercise-induced oxidative stress were carried out with exercise protocols including typical aerobic (running and cycling) and anaerobic (resistance training and sprints) exercise . Intermittent exercises such as sporting games (soccer, handball, water polo, basketball, etc.) involve both aerobic and anaerobic metabolism and have been received small attention in the literature. Water polo is an example of intermittent (“interval”) sport, requiring a high fraction of oxygen consumption, and is composed by high intensity bursts of sprinting, each lasting between 7 to 14 seconds, interspersed with short periods of low to moderate intensity swimming .