Altitude Training Effectiveness; Is There a Role for Sleep and Menstrual Health?

Therefore, the present study aims to evaluate the role of the impact of altitude on sleep and the menstrual cycle in the inter- and intraindividual variability of altitude training effectiveness. In order to do so, elite female cyclists will be monitored before, during and after an altitude training camp. The monitoring will include menstrual cycle characteristics, sleep and altitude effectiveness and will start three months before the start of the altitude training camp and end two months after the altitude training camp. Both naturally cycling women and women using contraceptives will be included in the study. Menstrual cycle monitoring will take place via self-reports and via a daily saliva (Eli Health) and urine (Proov) test to measure progesterone concentration. Besides proges-terone concentration, the sampled urine will also be used to perform an ovulation test on (i.e., measuring the luteinizing hormone). In addition, a blood sample will be collected at the start of each menstrual cycle to evaluate the concentration of menstrual cycle-related hormones (e.g., fol-licle-stimulating hormone, luteinizing hormone, estrogen, and progesterone) and to evaluate the functioning of the Hypothalamic-Pituitary-Adrenal Axis (i.e., cortisol concentration). Sleep moni-toring will be performed via the use of questionnaires, actigraphy and polysomnography. Lastly, altitude effectiveness will be evaluated via the altitude-associated response in total hemoglobin mass and via an all out cycle ergometer task.