Bone Metabolism in Premenopausal Exercising Women (BeWOMEN)

Bone Metabolism in Exercising WOMEN: Influence of Low Energy Availability and Sex Hormone Fluctuations

The main goal of this study is to examine how sex hormones and low energy availability affect the concentrations of bone remodelling markers at rest and after a running protocol. The research questions to be addressed are:

1: Does the ovarian hormone profile influence serum bone marker concentrations in women exercising resting and in response to to exercise?

2. Are there differences in response to low energy availability in bone marker concentrations between eumenorrhoeic female athletes and oral contraceptive users?

3: Is the response of bone markers affected by different exercise stimuli: endurance or aerobic endurance?

4: Do bone markers return to baseline levels after 24 hours of high energy availability diet after 6 days of low energy availability?

Study Overview

• Status: Enrolling by invitation
• Conditions: Contraception; Bone Metabolism; Eumenorrhea; Low Energy Availability
• Intervention / Treatment: Other: Low energy availability; Other: High energy availability

Detailed Description

To achieve the aim of the study, there will be two experimental groups - e.g. eumenorrhoeic females and oral contraceptive users - who, after screening, will be randomly assigned to a low- or high-energy diet. After 6 days on this diet, the participant will undergo an intervallic running protocol and blood samples will be taken before and after the test. The following month the participant will do the other type of diet.

• Study Type: Interventional
• Enrollment (Estimated): 22
• Phase: Not Applicable

Contacts and Locations

Study Locations

• Spain
  • Comunity of Madrid
    • Madrid, Comunity of Madrid, Spain, 28040
      • Faculty of physical activity and sport sciences

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult
• Accepts Healthy Volunteers: Yes

Description

Inclusion Criteria:

• Be healthy and between 18 and 30 years old.
• Engage in endurance sports that involve running (such as athletics, running, triathlon, trail running, etc.) for 3 to 12 hours per week..
• Eumenorrheic females with regular menstruation at least 6 months prior to the study.
• Monophasic oral contraceptive users at least 6 months prior to the study.

Exclusion Criteria:

• Amenorrheic females.
• Pregnant females.
• Affected by any disorder related to the hypothalamo-pituitary-ovarian axis.
• Having suffered a bone fracture in the year before the study.
• Taking any medication or supplements that affect bone metabolism.

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Basic Science
• Allocation: Non-Randomized
• Interventional Model: Crossover Assignment
• Masking: None (Open Label)

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: Eumhenorreic females	Other: Low energy availability; Participants follow 6 days of a low-energy availability diet. The kilocalories of each diet are prescribed individually based on their fat-free mass.; Other: High energy availability; Participants follow 6 days of a high-energy availability diet. The kilocalories of each diet are prescribed individually based on their fat-free mass.
Experimental: Oral concetraceptive users	Other: Low energy availability; Participants follow 6 days of a low-energy availability diet. The kilocalories of each diet are prescribed individually based on their fat-free mass.; Other: High energy availability; Participants follow 6 days of a high-energy availability diet. The kilocalories of each diet are prescribed individually based on their fat-free mass.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Concentration of bone metabolism biomarkers	Concentration of procollagen type I N-propeptide (P1NP), cross-linking telopeptide of type I collagen (βCTX-1), paratyroid hormone, calcium, sclerostin, osteoprotegin, osteocalcin, bone alkaline phospatase, Receptor Activator for Nuclear Factor κ B Ligand (RANKL) measured in serum samples.	immediately pre-exercise and immediately, 15 minutes and 24 hours post-exercise
Concentrations of other biochemical biomarkers	Concentrations of Triiodothyronine (T3), Albumin, Sex Hormone Binding Globulin (SHBG), etc. measured in serum	Immediately pre-exercise and immediately, 15 minutes and 24 hours post-exercise
Concentrations of sex hormones	Concentrations of 17β-Oestradiol and Progesterone measured in serum.	Immediately pre-exercise and immediately, 15 minutes and 24 hours post-exercise
Bone mineral density	Total, lumbar spine and femoral neck bone mineral density (g/cm^2) measured by dual x-ray absorptiometry	At the screening phase

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Training status variables	Oxygen uptake at ventilatory threshold 1, ventilatory threshold 2, and maximal oxygen uptake (ml/kg/min) measured with a gas analyser.	At the screening phase
Body composition variables	Fat mass (kg), fat free mass (kg), fat mass percentage, fat-free mass percentage (FFM), total mass (kg) measured by dual x-ray absorptiometry	Immediately pre- and post-nutritional intervention (bioimpedance) and DXA at the screening
Body metrics	Height (cm)	Measured at the screening phase

Collaborators and Investigators

• Sponsor: Universidad Politecnica de Madrid

Study record dates

Study Major Dates

• Study Start (Actual): December 5, 2024
• Primary Completion (Estimated): December 20, 2025
• Study Completion (Estimated): June 15, 2026

Study Registration Dates

• First Submitted: March 6, 2025
• First Submitted That Met QC Criteria: May 5, 2025
• First Posted (Actual): May 8, 2025

Study Record Updates

• Last Update Posted (Actual): May 8, 2025
• Last Update Submitted That Met QC Criteria: May 5, 2025
• Last Verified: May 1, 2025

More Information

Terms related to this study

• Other Study ID Numbers: 2023-091

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No
• product manufactured in and exported from the U.S.: No