Influence of Menstrual Cycle Stages on Female Athletes

The influence of the menstrual cycle on women's sports performance is still uncertain. Research on this topic shows methodological biases. The aim of the study will be to determine whether the menstrual cycle affects women's physical fitness, measuring this in 3 differentiated stages of the cycle: the early follicular phase, late follicular phase, and luteal phase. For this purpose, a blood test will be carried out in each phase, with hormone determination (oestradiol and progesterone) and a haemogram to determine the existence of possible anemia. After the extraction and other complementary tests (measurement of vital signs, bioimpedance...) the woman will undergo 3 physical tests to compare the results in the 3 phases. A group of women taking hormonal contraception will also be included, performing the same interventions. To determine whether the woman is ovulating or not, urinary luteinizing hormone (LH) strips will be given to the women and they will have to take them from day 8 of the cycle. In addition, women will wear an accelerometer to monitor their daily activity and to be able to observe if there is an influence on this stage of the menstrual cycle.