How the menstrual cycle affects energy use during exercise
| ISRCTN | ISRCTN50133765 |
|---|---|
| DOI | https://doi.org/10.1186/ISRCTN50133765 |
| Secondary identifying numbers | NIHR Nottingham Biomedical Research Centre BRC-1215–20003 |
- Submission date
- 14/04/2025
- Registration date
- 11/06/2025
- Last edited
- 11/06/2025
- Recruitment status
- No longer recruiting
- Overall study status
- Completed
- Condition category
- Nutritional, Metabolic, Endocrine
Plain English summary of protocol
Background and study aims
In recent years, the activities of female athletes have been increasing. However, research has tended to focus on the male population, and less is known about the effects of the menstrual cycle on energy use during exercise. During exercise, the human body uses ingested food to provide energy to the muscles used. This food is broken down and stored as glycogen or fat in the liver and muscles, ready to supply energy when needed. The amount of glycogen and fats used during exercise can influence performance, fatigue and health outcomes and understanding these dynamics is foundational in sports medicine and metabolic disorders (e.g. diabetes). This study aims to investigate how variations in hormones throughout the menstrual cycle impact energy use in the muscle and liver to provide foundational knowledge for future research and public health policies.
Who can participate?
Active healthy female participants aged 18 - 35 who have regular menstrual cycle (25 - 38 days) and undertake regular moderate exercise (e.g. 45 minutes brisk walking or light running 3 days per week).
What does the study involve?
After an initial set-up visit (outlined below), participants will attend the test centre on 4 separate occasions, one week apart, each after a standardized breakfast. Blood samples will be taken to determine hormonal levels, and ovulation kits will be provided so that the menstruation status of each visit is precisely known. In an initial set-up visit (before the main 4-week study), participants will undertake an exercise test on a stationary exercise bike to determine the intensity needed for a personalised exercise at 70% of their maximum exercise capacity (called 70% VO2 max). Following this, for each of the 4 weekly visits, participants will undergo a 45-minute cycle exercise where the researcher will maintain the intensity at their pre-determined 70% VO2 max. Before and after each cycle of exercise, participants will undergo a 15-30 minute MRI scan, and blood samples will be taken. Data from the MRI scan will be used to determine glycogen concentrations in the liver and muscle, and blood analysis will be used to determine glucose, lipid and lactate levels. The difference in the before- and after-exercise measurement will be used to determine how much of each metabolite has been used during exercise.
What are the possible benefits and risks of participating?
This study is a basic science physiological study, and so there are no direct health benefits to participants. However, the measurements will provide crucial data for future research. The risks in taking part are minimal as there are no experimental interventions. There are some small risks associated with MRI (such as heating and noise) which are outlined in detail in the participant information sheet and carefully mitigated against in the study. Similarly, there are small risks associated with taking a blood sample.
Where is the study run from?
Queen's Medical Centre, Nottingham
When is the study starting and how long is it expected to run for?
September 2021 to September 2023
Who is funding the study?
NIHR Nottingham Biomedical Research Centre
Who is the main contact?
Dr. Stephen Bawden, stephen.bawden1@nottingham.ac.uk
Contact information
Scientific
Clinical Imaging Facility
ILS2 College of Medicine
Swansea
SA2 8PP
United Kingdom
 ORCID ID |
0000-0002-5157-3269 |
|---|---|
| Phone | +44 (0)1792703729 |
| stephen.bawden1@nottingham.ac.uk |
Principal Investigator
Room W/E 1418 E Floor, West Block
Queen's Medical Centre
Nottingham
NG7 2UH
United Kingdom
| ORCID ID |
0000-0003-3924-4830 |
|---|---|
| Phone | +44 (0)115 823 1031 |
| guru.aithal@nottingham.ac.uk |
Public
Sir Peter Mansfield Imaging Centre, Building 18
University Park Campus
Nottingham
NG72QX
United Kingdom
| Phone | +44 (0)115 9514747 |
|---|---|
| Henry.Bowler@nottingham.ac.uk |
Study information
| Study design | Single-centre observational study |
|---|---|
| Primary study design | Observational |
| Secondary study design | Longitudinal study |
| Study setting(s) | University/medical school/dental school |
| Study type | Other |
| Participant information sheet | 47187_PIS_V1.0_16Aug2021.pdf |
| Scientific title | Influence of the menstrual cycle on muscle and liver glycogen and circulating substrates during exercise in healthy women |
| Study acronym | IMCOM |
| Study objectives | Variations in ovarian hormones throughout the menstrual cycle significantly affect glycogen utilisation in the liver and muscle during exercise, as measured by 13C-MRS, with distinct differences observed across the early follicular phase (E-FP), late follicular phase (L-FP), early luteal (E-LP) and late luteal phase (L-LP). |
| Ethics approval(s) |
Approved 24/09/2021, Faculty of Medicine and Health Sciences Research Ethics Committee (Room E41, E floor, Medical School, Queens Medical Centre Campus, Nottingham University Hospitals, Nottingham, NG72UH, United Kingdom; +44 (0)115 9515 559; FMHS-ResearchEthics@nottingham.ac.uk), ref: FMHS 323-0821 |
| Health condition(s) or problem(s) studied | Natural changes in metabolic responses to exercise over the menstrual cycle. |
| Intervention | A single-centre observational study where the metabolic responses to exercise will be measured in healthy female participants at 4 weekly timepoints throughout their menstrual cycle. Healthy active females (aged 18-35) with regular menstrual cycles and no hormonal contraceptives will attend the test centre after a standardized breakfast and partake in a 45-minute cycle exercise at 70% VO2 max. Liver and muscle glycogen levels will be measured using 13C Magnetic Resonance Spectroscopy (MRS) before and after exercise. Blood samples will also be taken alongside MRS to measure sex hormones, glucose, lipids and lactate. |
| Intervention type | Other |
| Primary outcome measure | Exercise-induced changes in liver glycogen concentrations (difference between before and after 45-minute cycle exercise) measured using 13C Magnetic Resonance Spectroscopy (MRS) on 4 separate occasions, one week apart. |
| Secondary outcome measures | 1. Exercise-induced changes in muscle glycogen concentrations (difference between before and after 45-minute cycle exercise) measured using 13C MRS at 4 separate occasions, one week apart. 2. Blood metabolites (glucose, lactate, lipids) and hormones (estradiol, progesterone, luteinizing hormone and follicular stimulating hormone) measured before and after a 45-minute cycle exercise using blood assays on 4 separate occasions, one week apart. |
| Overall study start date | 24/09/2021 |
| Completion date | 01/09/2023 |
Eligibility
| Participant type(s) | Healthy volunteer |
|---|---|
| Age group | Adult |
| Lower age limit | 18 Years |
| Upper age limit | 35 Years |
| Sex | Female |
| Target number of participants | 12 |
| Total final enrolment | 10 |
| Key inclusion criteria | 1. Female 2. Age 18 - 35 years 3. Regular menstrual cycle (every 25 - 38 days) 4. Nulliparous 5. Habitual exercise - 45 minutes of moderate exercise (brisk walking or jogging), minimum 3 days per week |
| Key exclusion criteria | 1. A history of smoking or chronic diseases 2. Use of oral contraceptives or other hormone medications for at least 6 months prior 3. Pregnancy or lactation 4. Pearning difficulties or cognitive impairments or social problems or substance abuse, or mental illness, which would make it difficult to complete the protocol |
| Date of first enrolment | 01/09/2021 |
| Date of final enrolment | 01/09/2023 |
Locations
Countries of recruitment
- England
- United Kingdom
Study participating centre
University of Nottingham
University Park
Nottingham
NG7 2UH
United Kingdom
Sponsor information
University/education
University Park
Nottingham
NG7 2RD
England
United Kingdom
| Phone | +44 (0)1159515151 |
|---|---|
| guru.aithal@nottingham.ac.uk | |
| Website | https://www.nottingham.ac.uk/ |
"ROR" |
https://ror.org/01ee9ar58 |
Funders
Funder type
Government
Government organisation / Research institutes and centers
- Alternative name(s)
- Nottingham Biomedical Research Centre, Nottingham Biomedical Research Centre - NIHR, NIHR Nottingham BRC, BRC, NIHR NBRC
- Location
- United Kingdom
Results and Publications
| Intention to publish date | 01/10/2025 |
|---|---|
| Individual participant data (IPD) Intention to share | Yes |
| IPD sharing plan summary | Available on request |
| Publication and dissemination plan | Findings planned to be presented in international MRI conference (ISMRM) and published in peer reviewed journal |
| IPD sharing plan | The datasets generated and analysed during the current study will be available upon request from Dr. Stephen Bawden, stephen.bawden1@nottingham.ac.uk |
Study outputs
| Output type | Details | Date created | Date added | Peer reviewed? | Patient-facing? |
|---|---|---|---|---|---|
| Other files | 05/08/2021 | 16/04/2025 | No | No | |
| Participant information sheet | version 1.0 | 16/08/2021 | 16/04/2025 | No | Yes |
| Protocol file | version 1.1 | 17/09/2021 | 16/04/2025 | No | No |
Additional files
Editorial Notes
14/04/2025: Faculty of Medicine and Health Sciences Research Ethics Committee, University of Nottingham.
