The Effects of Combined Energy and Carbohydrate Restriction on Exercise Capacity (CHO-EX)

February 27, 2026 updated by: Mette Hansen, University of Aarhus

The Effects of Combined Energy and Carbohydrate Restriction on Exercise Capacity and Health in Overweight Women

The effect of calorie restriction combined with low or moderate carbohydrate availability on exercise capacity, metabolism and metabolic health indicators will be measured in a randomized parallel group design. Forty overweight (BMI 25-30) and relatively inactive women (20-35 of age) will be included. These will be randomized into one of two experimental groups both receiving a calorie-restricted diet (-1000 kcal) combined with either low carbohydrate availability or moderate carbohydrate availability across a 10 day period. Laboratory-based physical capacity tests and blood and muscle sampling will be performed before and after the intervention. In addition, an additional follow-up test day will be performed after continuing the diet for another 48 h and then standardizing the pre-testing carbohydrate availability before repeating the tests of physical capacity.

Study Overview

Status

Status

Indicates the current recruitment status or the expanded access status.
Completed

Conditions

Conditions

The disease, disorder, syndrome, illness, or injury that is being studied. On ClinicalTrials.gov, conditions may also include other health-related issues, such as lifespan, quality of life, and health risks.

Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.

Detailed Description

Overweight (BMI 25-30), but healthy premenopausal women aged 20-35 years (n=40) will be included in the trial, which is structured as a randomized, parallel group design where participants are randomized to either consume a hypocaloric diet (-1000 kcal) with concurrent carbohydrate restriction (low carbohydrate, L-CHO, n=20) or a similar hypocaloric diet with moderate carbohydrate availability (moderate carbohydrate, M-CHO, n=20). The trial will be single-blinded since it might be transparent to the participants which diet they are consuming, whereas the test personnel collecting and processing test results will be blinded to diet allocation. Diet handling will be managed by specific individuals in the research group who do not partake in executing the physical capacity tests. Additionally, the direction of the trial's primary hypothesis will not be disclosed to the participants to avoid creating preconceived expectations about the effects.

After an initial screening interview and two familiarization visits, participants will complete the intervention period consisting of 10 days with the allocated diet manipulation with preceding and subsequent test days with a series of tests. The tests before and after each test period include measurements of the participants' physical capacity level and energy metabolism in the laboratory as well as blood and muscle sampling. In addition, resting metabolism and body composition will be measured. During each test period, participants' habitual activity level will be monitored with an accelerometer attached to the wrist (Axivity). There will also be monitoring of the activity level with an accelerometer in a 7-day cycle before the start of the trial as a baseline measurement.

Similarly, a glucose monitor will be placed on the upper arm for continuous glucose readings via a Freestyle Libre2 sensor during the trial period.

Study Type

Study Type

Describes the nature of a clinical study. Study types include interventional studies (also called clinical trials), observational studies (including patient registries), and expanded access.
Interventional

Enrollment (Actual)

Enrollment

The number of participants in a clinical study. The "anticipated" enrollment is the target number of participants that the researchers need for the study.
36

Phase

Phase

The stage of a clinical trial studying a drug or biological product, based on definitions developed by the U.S. Food and Drug Administration (FDA). The phase is based on the study's objective, the number of participants, and other characteristics. There are five phases: Early Phase 1 (formerly listed as Phase 0), Phase 1, Phase 2, Phase 3, and Phase 4. Not Applicable is used to describe trials without FDA-defined phases, including trials of devices or behavioral interventions.
  • Not Applicable

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Contact

Study Contact

The name and contact information for the person who can answer enrollment questions for a clinical study. Each location where the study is being conducted may also have a specific contact, who may be better able to answer those questions.
  • Name: Mette Hansen, PhD
  • Phone Number: +4551666551
  • Email: mhan@ph.au.dk

Study Contact Backup

Study Locations

  • Denmark
      • Aarhus C, Denmark, 8000
        • Section for Sport Science, Department of Public Health, Aarhus University

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Eligibility Criteria

The key requirements that people who want to participate in a clinical study must meet or the characteristics they must have. Eligibility criteria consist of both inclusion criteria (which are required for a person to participate in the study) and exclusion criteria (which prevent a person from participating). Types of eligibility criteria include whether a study accepts healthy volunteers, has age or age group requirements, or is limited by sex.

Ages Eligible for Study

  • Adult

Accepts Healthy Volunteers

Yes

Description

Inclusion Criteria:

  • Age: 20-35
  • BMI: 25-30

Exclusion Criteria:

  • Irregular menstruation within the last 6 months (shorter end 24 days or longer end 35 days cycle)
  • Injuries / pain in the lower body, which prevents participation in intense cycling
  • Medication consumption that may affect primary outcome measures.
  • Smoking
  • Pregnancy
  • Systematic physical activity more than 2 hours per week

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Treatment
  • Allocation: Randomized
  • Interventional Model: Parallel Assignment
  • Masking: Triple

Arms and Interventions

Participant Group / Arm

Participant Group / Arm

A group or subgroup of participants in a clinical trial that receives a specific intervention/treatment, or no intervention, according to the trial's protocol.
Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.
Active Comparator: Low-carbohydrate calorie-restriction
Minimum of 3 g carbohydrate/kg body weight/day and a ~1000 kcal calorie restriction
Other: Calorie-restriction with low carbohydrate
Calorie-restriction and low carbohydrate availability
Experimental: Moderate-carbohydrate calorie-restriction
Maximum of 1 g carbohydrate/kg body weight/day and a ~1000 kcal calorie restriction
Other: Calorie-restriction with moderate carbohydrate
Calorie-restriction and moderate carbohydrate availability

What is the study measuring?

Primary Outcome Measures

Primary Outcome Measures

In a clinical study's protocol, the planned outcome measure that is the most important for evaluating the effect of an intervention/treatment. Most clinical studies have one primary outcome measure, but some have more than one.
Outcome Measure
Measure Description
Time Frame
Time to exhaustion
Time Frame: Pre, post (day 11 of the intervention) and follow-up (day 2 after the post measurement)
Time to exhaustion at 85% VO2max
Pre, post (day 11 of the intervention) and follow-up (day 2 after the post measurement)
Sprint performance
Time Frame: Pre, post (day 11 of the intervention) and follow-up (day 2 after the post measurement)
Peak and mean 15-s sprint performance
Pre, post (day 11 of the intervention) and follow-up (day 2 after the post measurement)
Exercise tolerance
Time Frame: Pre, post (day 11 of the intervention) and follow-up (day 2 after the post measurement)
Ratings of perceived exertion (Borg scale) during standardized-intensity exercise from 6 (lowest exertion) to 20 (highest exertion)
Pre, post (day 11 of the intervention) and follow-up (day 2 after the post measurement)
Muscle glycogen levels
Time Frame: Pre and post (day 11 of the intervention)
Muscle glycogen levels obtained from biopsy sample
Pre and post (day 11 of the intervention)

Secondary Outcome Measures

Secondary Outcome Measures

In a clinical study's protocol, a planned outcome measure that is not as important as the primary outcome measure for evaluating the effect of an intervention but is still of interest. Most clinical studies have more than one secondary outcome measure.
Outcome Measure
Measure Description
Time Frame
Physical activity level
Time Frame: During the intervention (days 1 to 11 of the intervention)
Measured with accelerometer during the intervention
During the intervention (days 1 to 11 of the intervention)
Maximal fat oxidation capacity
Time Frame: Pre, post (day 11 of the intervention) and follow-up (day 2 after the post measurement)
Maximal fat oxidation measured in the laboratory
Pre, post (day 11 of the intervention) and follow-up (day 2 after the post measurement)
Muscle metabolic enzyme activity
Time Frame: Pre and post (day 11 of the intervention)
Activity of key enzymes involved in carbohydrate and fat metabolism
Pre and post (day 11 of the intervention)
Blood lipid profile
Time Frame: Pre and post (day 11 of the intervention)
High-density lipoproteins, low-density lipoproteins, very-low-density lipoproteins, cholesterol, free fatty acids and triglycerides
Pre and post (day 11 of the intervention)
Continuous glucose levels
Time Frame: 14 days from the day before the intervention, throughout the intervention (days 1 to 11) and 2 days after the intervention (follow-up)
Glucose levels measured continuously across the trial + during exercise tests
14 days from the day before the intervention, throughout the intervention (days 1 to 11) and 2 days after the intervention (follow-up)
Fasting blood glucose and insulin
Time Frame: Pre and post (day 11 of the intervention)
Insulin sensitivity (Homa 2 IR)
Pre and post (day 11 of the intervention)
Long-term glycemic control (HbAc1)
Time Frame: Pre and post (day 11 of the intervention)
Measured from fasting blood
Pre and post (day 11 of the intervention)

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Sponsor

The organization or person who initiates the study and who has authority and control over the study.
University of Aarhus

Collaborators

Collaborators

An organization other than the sponsor that provides support for a clinical study. This support may include activities related to funding, design, implementation, data analysis, or reporting.
University of Southern Denmark
University Ghent

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Actual)

Study Start

The actual date on which the first participant was enrolled in a clinical study. The "anticipated" study start date is the date that the researchers think will be the study start date.
April 1, 2024

Primary Completion (Actual)

Primary Completion

The date on which the last participant in a clinical study was examined or received an intervention to collect final data for the primary outcome measure. Whether the clinical study ended according to the protocol or was terminated does not affect this date. For clinical studies with more than one primary outcome measure with different completion dates, this term refers to the date on which data collection is completed for all the primary outcome measures. The "anticipated" primary completion date is the date that the researchers think will be the primary completion date for the study.
June 15, 2025

Study Completion (Actual)

Study Completion

The date on which the last participant in a clinical study was examined or received an intervention/treatment to collect final data for the primary outcome measures, secondary outcome measures, and adverse events (that is, the last participant's last visit). The "anticipated" study completion date is the date that the researchers think will be the study completion date.
July 1, 2025

Study Registration Dates

First Submitted

First Submitted

The date on which the study sponsor or investigator first submitted a study record to ClinicalTrials.gov. There is typically a delay of a few days between the first submitted date and the record's availability on ClinicalTrials.gov (the first posted date).
April 5, 2024

First Submitted That Met QC Criteria

First Submitted That Met QC Criteria

The date on which the study sponsor or investigator first submits a study record that is consistent with National Library of Medicine (NLM) quality control (QC) review criteria. The sponsor or investigator may need to revise and submit a study record one or more times before NLM's QC review criteria are met. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
April 19, 2024

First Posted (Actual)

First Posted

The date on which the study record was first available on ClinicalTrials.gov after National Library of Medicine (NLM) quality control (QC) review has concluded. There is typically a delay of a few days between the date the study sponsor or investigator submitted the study record and the first posted date.
April 24, 2024

Study Record Updates

Last Update Posted (Actual)

Last Update Posted

The most recent date on which changes to a study record were made available on ClinicalTrials.gov. There may be a delay between when the changes were submitted to ClinicalTrials.gov by the study's sponsor or investigator (the last update submitted date) and the last update posted date.
March 2, 2026

Last Update Submitted That Met QC Criteria

Last Update Submitted That Met QC Criteria

The most recent date on which the study sponsor or investigator submitted changes to a study record that are consistent with National Library of Medicine (NLM) quality control (QC) review criteria. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
February 27, 2026

Last Verified

Last Verified

The most recent date on which the study sponsor or investigator confirmed the information about a clinical study on ClinicalTrials.gov as accurate and current. If a study with a recruitment status of recruiting; not yet recruiting; or active, not recruiting has not been confirmed within the past 2 years, the study's recruitment status is shown as unknown.
February 1, 2026

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

Other Study ID Numbers

Identifiers or ID numbers other than the NCT number that are assigned to a clinical study by the study's sponsor, funders, or others. These numbers may include unique identifiers from other trial registries and National Institutes of Health grant numbers.
  • 1-10-72-19-24

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

UNDECIDED

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

Clinical Trials on Overweight and Obesity

Clinical Trials on Calorie-restriction with low carbohydrate

Search Similar Trials

Sponsors and Collaborators

Medical Conditions

Drug Interventions

Conditions

Rare Diseases

Drug Interventions

Dietary Supplements

Sponsor/Collaborators

Locations

Cookie Settings

We use cookies to ensure that we give you the best experience on our website. For more details carefully read our Privacy and Cookies Policy. ...>>>You can change your preferences or withdraw your consent at any time by deleting the cookies from your website or computer as described in the policy. Please accept it and choose your preferences by ticking the corresponding boxes in the "Manage Settings" section below. Please carefully read our Terms of Service before you proceed with using any part of this website.
«Manage Settings