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

Inclusion Criteria:

• participates in structured running or cycling exercise for at least 30 minutes on 4days 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 notbeen 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, ovarianinsufficiency, 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 aerobic exercise (i.e., running, cycling, crosstraining) if assigned to the exercise intervention groups

• they indicate they "Could not participate at all due to a health problem" or havehad to modify their exercise training, felt their injury, illness, or other healthproblem has affected their exercise performance, or experienced symptoms/ healthcomplaints greater than "To a minor extent" on the Oslo Sports Trauma ResearchCenter Questionnaire (exercise training intervention group)

• demonstrate clinical low energy availability as defined as energy availability <30Kcal/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 ofat-home monitoring

• do not demonstrate an anticipated rise in progesterone levels during the latter halfof their cycle and luteinizing hormone levels at mid-cycle compared to tests takenduring 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, premenstrualdysphoric disorder [PMDD], menstrual migraines, ovarian cancer, ovarianinsufficiency, 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 majorcardiovascular disease, respiratory disease, or musculoskeletal injury

• are unable to follow instructions for any of the procedures