Abstract
The Female Athlete Triad (Triad) and Relative Energy Deficiency in Sport (RED-S) are conditions associated with low energy availability (EA) that can lead to menstrual dysfunction, impaired bone health, and metabolic disturbances. This case report describes the remission of Triad in a professional triathlete during the COVID-19 pandemic. A 24-year-old female triathlete was evaluated in 2018. She reported bulimia nervosa from 12-15 years old and hypothalamic amenorrhea since she was 21 years old. Her training volume was approximately 20 hours per week (swimming, cycling, and running), and the amount of EA was critically low (< 10 kcal/fat free mass/day). The athlete had lower than expected BMD at DXA scan (lumbar spine Z-score -2.3 SD) and lower cortical and trabecular vBMD and trabecular number by comparison with HR-pQCT normative data for young Brazilian women. During the 2020 pandemic, training centers were closed, leading to a decrease in exercise volume and a more balanced energy intake. Menstrual cycles resumed and she conceived spontaneously in the same year. Pregnancy and postpartum recovery were uneventful. She returned to competitions post pandemic, but no longer as a professional athlete. Chronic energy deficiency significantly affects the hypothalamic-pituitary-gonadal axis and bone health. A forced reduction in training intensity and improved dietary intake were key factors in the restoration of menstrual function and reproductive health. This case highlights the potential reversibility of the Female Athlete Triad when energy balance is restored. Awareness and early intervention are essential for preventing long-term consequences in female athletes.