The impact ofcompetitive sport on the age of menarche,occurrence of amenorrhea,and characteristics of themenstrual cycle

In recent decades, female participation in competitivesports has increased significantly. While physical activityoffers numerous health benefits, intensive training canadversely affect the menstrual cycle. The aim of thisstudy was to analyze the impact of competitive sports onmenstrual disorders and cycle characteristics among femaleathletes from different countries and sports disciplines.This retrospective, cross-sectional study included 369women, of whom 298 were athletes (experimental group)and 71 were non-athletes (control group). Participantscompleted an online questionnaire collecting data on age atmenarche, incidence of primary and secondary amenorrhea,menstrual bleeding regularity, duration and intensity, andthe intensity of menstrual pain. Athletes were furthercategorized by sport (swimming, athletics, gymnastics,basketball, water polo) and country of training (USA,Croatia, Spain, Singapore). Statistical analyses includedt-tests, chi-square tests, ANCOVA, and post-hoc tests.Athletes experienced significantly later menarchecompared to non-athletes (12.9 vs. 11.5 years; p < 0.001),with the highest age at menarche observed in gymnasts(13.79). Primary amenorrhea was reported in 4.7% ofathletes, varying significantly by sport (p = 0.009), whileno cases were recorded among non-athletes. Secondaryamenorrhea was more prevalent among athletes (37.6%)than non-athletes (18.3%; p = 0.002), although there wasno significant difference in its duration between groups.Athletes reported shorter menstrual bleeding (5.2 vs. 5.8days; p < 0.001), with the shortest duration observed amongSpanish athletes (4.8 ± 1.3), and lighter menstrual flow (3.5 vs 3.4, p = 0.044), which did not significantly vary by sportor country of training.No significant difference was found in the intensity ofmenstrual pain between athletes and non-athletes, althoughdifferences were noted among countries, with participantsfrom Singapore reporting the least intense pain (2.9/6).Competitive sports are associated with alterationsin menstrual function, including delayed menarche,higher prevalence of secondary amenorrhea, and shorter,lighter menstrual bleeding. These findings highlight theimportance of education and monitoring of female athletes’reproductive health, with timely recognition and treatmentof menstrual disorders essential to preserving long-termhealth and athletic performance.