Timing of Energy Availability on Menstrual Cycle Function

Last updated: January 9, 2025
Sponsor: University of Colorado, Colorado Springs
Overall Status: Active - Recruiting

Phase

N/A

Condition

Premenstrual Syndrome

Menopause

Menstrual Disorders

Treatment

Artificially Sweetened Beverage

Artificially Sweetened Carbohydrate Beverage

Clinical Study ID

NCT06471582
FAST
  • Ages 18-40
  • Female
  • Accepts Healthy Volunteers

Study Summary

The primary aim of this clinical trial is to evaluate how fasted prolonged exercise may influence circulating reproductive hormones (i.e., estradiol, progesterone, luteinizing hormone) and menstrual cycle length when energy availability is maintained at or above 30 kcal/kg lean body mass/ day among women who regularly do running or cycling exercise. A secondary aim is to determine the effects of fasted prolonged exercise on serum leptin and cortisol.

Participants will be asked to do the following over a ~3 month enrollment period:

  • attend a laboratory visit at the beginning of the study to have their resting metabolic rate, aerobic fitness, and body composition tested

  • monitor their menstrual cycle length, urine hormones, perceived stress levels, and diet for ~3 months

  • complete 3, 90-minute exercise sessions on a stationary bike or treadmill either fed (consuming a carbohydrate meal 1 h prior and 0.7 g carbohydrate/ kg body mass/ h during exercise) or fasted (consuming no meal prior and no carbohydrates during exercise) during month ~3

  • saliva samples will be taken prior to and after 90-minute exercise sessions for quantification of leptin and cortisol

Eligibility Criteria

Inclusion

Inclusion Criteria:

  • participates in structured running or cycling exercise for at least 30 minutes on 3or more days per week

  • accustomed to exercising for 90 minutes or more

  • has regular periods every 21-35 days

  • have not taken hormonal contraceptives for at least the past 6 months

  • is not currently or trying to become pregnant or breastfeeding, and has not beenpregnant or breastfeeding in the past 12 months

  • does not currently have a diagnosis of a major menstrual cycle disorder (i.e.,amenorrhea, polycystic ovary syndrome [PCOS], endometriosis, ovarian cancer, ovarianinsufficiency, uterine or endometrial cancer)

  • does not currently have a metabolic disease (i.e., hypothyroidism, hyperthyroidism,Cushing disease, Addison's disease, diabetes, congenital adrenal hyperplasia)

  • does not currently have a major cardiovascular or respiratory disease

Exclusion

Exclusion Criteria:

  • miss more than 7 consecutive days of aerobic activity (i.e., running, cycling, crosstraining)

  • demonstrate clinical low energy availability as defined as energy availability <30kcal/kg fat free mass

  • report menstrual cycle lengths <21 or >35 days in the first 2 months of at-homemonitoring

  • do not demonstrate an anticipated rise in luteinizing hormone and progesterone inthe first 2 months of at-home monitoring

  • begin taking a hormonal contraceptive

  • become pregnant

  • are diagnosed with a menstrual cycle disorder (i.e., amenorrhea, polycystic ovarysyndrome [PCOS], endometriosis, ovarian cancer, ovarian insufficiency, uterine, orendometrial cancer)

  • are diagnosed with a metabolic disease (i.e., hypothyroidism, hyperthyroidism,Cushing disease, Addison's disease, diabetes)

  • are diagnosed with a major cardiovascular or respiratory disease

  • are unable to follow instructions for any of the procedures

Study Design

Total Participants: 64
Treatment Group(s): 2
Primary Treatment: Artificially Sweetened Beverage
Phase:
Study Start date:
August 01, 2024
Estimated Completion Date:
August 31, 2027

Connect with a study center

  • William J. Hybl Sports Medicine and Performance Center

    Colorado Springs, Colorado 80918
    United States

    Active - Recruiting

Not the study for you?

Let us help you find the best match. Sign up as a volunteer and receive email notifications when clinical trials are posted in the medical category of interest to you.