Respiratory and perceived exertion variables during an intervallic endurance protocol through menstrual cycle phases

Respiratory variables, rating of perceived exertion (RPE) and perceived readiness (PR) can vary depending on the menstrual cycle phase due to the different sexual hormone environments found through it [1, 2]. Few studies compare more than 2 menstrual cycle phases and even fewer use intense intervallic endurance protocols [1, 2]. Additionally, oestrogen seems to have powerful effects in some exercise variables, although it may reduce muscle endurance capacity [3]. Therefore, the main objective of this study was to compare respiratory variables, RPE and PR measured in 3 phases of the menstrual cycle during an intervallic endurance protocol.