The Effects of Combined Energy and Carbohydrate Restriction on Exercise Capacity

NCT06381908 | Completed DMC

• 1 other identifier: 1-10-72-19-24
• Study Type: interventional
• Target: 36
• Locations: 1 country
• Sites: 1

Brief Summary

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.

Conditions

Overweight and Obesity

Keywords

Physical activity; Metabolism; Physical capacity; Macronutrients; Carbohydrate; Diet

Outcome Measures

Primary Outcomes (4)

• Time to exhaustion

  Time to exhaustion at 85% VO2max

  Pre, post (day 11 of the intervention) and follow-up (day 2 after the post measurement)

• Sprint performance

  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

  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

  Muscle glycogen levels obtained from biopsy sample

  Pre and post (day 11 of the intervention)

Secondary Outcomes (7)

• Physical activity level

  During the intervention (days 1 to 11 of the intervention)

• Maximal fat oxidation capacity

  Pre, post (day 11 of the intervention) and follow-up (day 2 after the post measurement)

• Muscle metabolic enzyme activity

  Pre and post (day 11 of the intervention)

• Blood lipid profile

  Pre and post (day 11 of the intervention)

• Continuous glucose levels

  14 days from the day before the intervention, throughout the intervention (days 1 to 11) and 2 days after the intervention (follow-up)

Study Arms (2)

Low-carbohydrate calorie-restriction

ACTIVE COMPARATOR

Minimum of 3 g carbohydrate/kg body weight/day and a \~1000 kcal calorie restriction

Other: Calorie-restriction with low carbohydrate

Moderate-carbohydrate calorie-restriction

EXPERIMENTAL

Maximum of 1 g carbohydrate/kg body weight/day and a \~1000 kcal calorie restriction

Other: Calorie-restriction with moderate carbohydrate

Interventions

Calorie-restriction with low carbohydrate OTHER

Calorie-restriction and low carbohydrate availability

Low-carbohydrate calorie-restriction

Calorie-restriction with moderate carbohydrate OTHER

Calorie-restriction and moderate carbohydrate availability

Moderate-carbohydrate calorie-restriction

Eligibility Criteria

• Age: 20 Years - 35 Years
• Sex: female
• Healthy Volunteers: Yes
• Age Groups: Adult (18-64)

You may qualify if:

• Age: 20-35
• BMI: 25-30

You may not qualify if:

• 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

Sponsors & Collaborators

• University Ghent: collaborator
• University of Aarhus: lead
• University of Southern Denmark: collaborator

Study Sites (1)

Section for Sport Science, Department of Public Health, Aarhus University

Aarhus C, 8000, Denmark

Location

MeSH Terms

Conditions

Overweight; Obesity; Motor Activity

Condition Hierarchy (Ancestors)

Overnutrition; Nutrition Disorders; Nutritional and Metabolic Diseases; Body Weight; Signs and Symptoms; Pathological Conditions, Signs and Symptoms; Behavior

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: RANDOMIZED
• Masking: TRIPLE
• Who Masked: CARE PROVIDER, INVESTIGATOR, OUTCOMES ASSESSOR
• Masking Details: The study is labelled as a single-blinded study because the investigators are blinded to the group allocation (the group allocation and diet handling is managed by a researcher not involved in other aspects of the data collection or processing). The participants are not informed about their allocated condition, however, it is conceivably possible for them to recognize this based on the food provided. However, the direction of the hypothesis will not be evident to the participants. Moreover, we include questionnaires before the post-tests related to their perceived diet allocation and their perception of the effect of the diet on the test assessments.
• Purpose: TREATMENT
• Intervention Model: PARALLEL
• Sponsor Type: OTHER
• Responsible Party: PRINCIPAL INVESTIGATOR
• PI Title: Professor. PhD

Model Details: The study is performed as a randomized single-blinded parallel group design. Randomization is performed into two groups using minimization based on a predetermined estimated VO2max middle value of 30.

Study Record Dates

• First Submitted: April 5, 2024
• First Posted: April 24, 2024
• Study Start: April 1, 2024
• Primary Completion: June 15, 2025
• Study Completion: July 1, 2025
• Last Updated: March 2, 2026

Record last verified: 2026-02

Locations

DK (1)