# research in the early 2000s on exercise performance & the menstrual cycle started to provide critical commentary on the methodological approach used in studies > In the early 2000s, articles started to provide critical commentary on the methodological approach used in studies investigating the effects of oestrogen and progesterone on different aspects of exercise performance [18, 47]. This began to raise an awareness of some of the technical flaws and issues within this field[[(Elliott-Sale et al., 2021)#^hulsb]] These were [[(Janse de Jonge, 2003)]]