Menstrual-Cycle and Hormonal-Contraceptive Tracking in Gaelic Football: From the Lab to the Field

Purpose: The purpose of this study was to describe the implementation of menstrual-cycle (MC) and hormonal-contraceptive (HC) tracking among Gaelic Football players, including the characterization of MC status and symptomatology, and to examine the effect of MC and oral-contraceptive-pill phases on daily wellness. Methods: Fourteen highly trained players (age 24.2 [3.5] y), including non-HC (n = 6), oral contraceptive pill (n = 7), and intrauterine system (n = 1) users, prospectively tracked their MC or HC alongside daily self-reported wellness measures for 4 months. A combination of calendar-based counting, urinary ovulation prediction testing, and a midluteal serum progesterone measurement was used to assess MC status. Results: Only 2 non-HC players were eumenorrheic. Two players exhibited oligomenorrhea (cycle length, 39 [4] d), and ovulation was not detected in one of them. Luteal phase deficiency was indicated in 2 players (serum progesterone range <1.0-7.5 nmol L-1). All players except 1 reported at least 1 negative MC-related symptom or HC side effect. Linear mixed-model analyses revealed that wellness measures were not affected by oral contraceptive pill phase (P > .05). Linear mixed-model analysis was not performed in non-HC users due to the small sample of eumenorrheic players (n = 2). Conclusions: Diverse reproductive profiles were observed, including HC use and subtle MC irregularities that would likely go undetected without prospective MC tracking using biochemical outcomes. This highlights the value of incorporating ovulation testing and blood sampling when establishing the MC status of athletes in applied research and practice where feasible. Applied researchers should anticipate practical challenges, including inconsistencies in ovulation testing timings and the time scale required to assess MC status among athletes.