Influence of menstrual- and hormonal contraceptive cycle on self-reported symptom severity and recovery measures across an annual season in female endurance athletes: The FENDURA project

This longitudinal study investigated 1) differences in self-reported cycle-related symptom severity and recovery measures (sleep quality, readiness to train, resting heart rate) between pre-bleeding, bleeding, and non-bleeding days in athletes using/not using hormonal contraception (HC); 2) associations between symptom severity and recovery measures. Fifty-eight female endurance athletes recorded recovery measures, perceived symptom severity, and menstruation/withdrawal (bleeding) days for one year. Athletes were grouped as: intrauterine system (IUS)-, implant-, progestin-only oral contraceptive (POC)-, combined oral contraceptive (COC)- and non-HC users. All groups reported higher symptom severity during bleeding compared to pre-bleeding and non-bleeding days (both p