Effects of Physical and Psychosocial Stress on Functional Hypothalamic Amenorrhea in Exercising Women (FHA)

Inclusion Criteria: participates in structured running or cycling exercise for at least 30 minutes on 4 days per week or more have regular periods every 21 to 35 days have not used hormonal contraceptives for at least the past 6 months are not currently or trying to become pregnant or are breastfeeding, and have not been pregnant or breastfeeding for the past 12 months have never been diagnosed with a menstrual cycle disorder (e.g., menorrhagia, amenorrhea, dysmenorrhea, polycystic ovary syndrome [PCOS], endometriosis, premenstrual dysphoric disorder [PMDD], menstrual migraines, ovarian cancer, ovarian insufficiency, uterine or endometrial cancer) have never been diagnosed with a metabolic disease (e.g., hypothyroidism, hyperthyroidism, Cushing disease, Addison's disease, diabetes) Exclusion Criteria: missing > 4 consecutive days of structured running or cycling exercise they indicate they "Could not participate at all due to a health problem" or have had to modify their exercise training, felt their injury, illness, or other health problem has affected their exercise performance, or experienced symptoms/ health complaints greater than "To a minor extent" on the Oslo Sports Trauma Research Center Questionnaire (exercise training intervention group) demonstrate clinical low energy availability as defined as energy availability <30 Kcal/kg fat free mass in the first two months of at-home monitoring report menstrual cycle lengths <21 days or >35 days in the first two months of at-home monitoring do not demonstrate an anticipated rise in progesterone levels during the latter half of their cycle or luteinizing hormone levels at mid-cycle compared to tests taken during the first few days after menses in the first two months of at-home monitoring begin taking a hormonal contraceptive become pregnant are diagnosed with a menstrual cycle disorder (e.g., menorrhagia, amenorrhea, dysmenorrhea, polycystic ovary syndrome [PCOS], endometriosis, premenstrual dysphoric disorder [PMDD], menstrual migraines, ovarian cancer, ovarian insufficiency, uterine or endometrial cancer) are diagnosed with a metabolic disease (e.g., hypothyroidism, hyperthyroidism, Cushing disease, Addison's disease, diabetes), 10) are diagnosed with a major cardiovascular disease, respiratory disease, or musculoskeletal injury are unable to follow instructions for any of the procedures