The Female Athlete Triad—the impact of running and type of diet on the regularity of the menstrual cycle assessed for recreational runners

BACKGROUND: The Female Athlete Triad (FAT) included three interrelated conditions including disordered eating, amenorrhea, and osteoporosis. The American College of Sports Medicine updated the definition of FAT to reflect the interdependence of low energy availability with or without eating disorders. The main aim of the study was to assess the impact of recreational running on potential disturbances in the regularity of women’s menstrual cycles. Additionally, this work compared differences in the menstrual cycle between women runners and women who did not regularly practice sports. The respondents were also asked about the type of diet they consumed. METHODS: A total of 360 women took part in the research. This group included 217 runners and 143 control. The authors’ questionnaire was used in the research. RESULTS: When compared to the control group, the runners had an increased frequency of menstrual cycles of <24 days (10.14% vs. 3.50%), fewer typical cycles of 25–31 days (75.58% vs. 86.71%), had fewer regular cycles per year (9.62 vs. 11.22), shorter duration of bleeding (4.79 vs. 5.27 days), and an increased frequency of painless menstruation (23.96% vs. 7.69%). A positive predictor of menstrual cycle disorders was the use of a ‘special diet’ (R:1.67; 95% C:0.47–2.87). CONCLUSIONS: The runners had shorter and less regular monthly cycles and shorter and more often painless menstrual bleeding when compared to the control group. The frequency of menstrual disorders in runners was increased by following a ‘special diet’. The frequency of menstrual cycle disorders in runners, however, did not differ significantly from the control group.