Glycaemic Index and Substrate Metabolism

NCT ID: NCT05241730

Last Updated: 2023-11-27

Study Results

Results pending

The study team has not published outcome measurements, participant flow, or safety data for this trial yet. Check back later for updates.

Basic Information

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Recruitment Status

COMPLETED

Clinical Phase

NA

Total Enrollment

65 participants

Study Classification

INTERVENTIONAL

Study Start Date

2022-01-10

Study Completion Date

2023-04-23

Brief Summary

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Substrate metabolism during exercise can be influenced by various nutritional regimes. The effectiveness of the different nutritional regimes, which differ in their carbohydrate content, will be investigated not only by functional tests but also the measurement of the mechanistic processes in the muscle will be explored.

Magnetic resonance (MR), better known as magnetic resonance imaging (MRI), has been widely used in clinical practice as a non-invasive imaging technique. Importantly, in addition to producing anatomical images, an MR scanner also offers the possibility to measure the concentrations of a number of metabolic products. This is done through a technique known as magnetic resonance spectroscopy (MRS).

This research project asks the following questions:

* Can a diet containing carbohydrates with a low glycemic index achieve the same adaptations in basic endurance/fat metabolism as a high fat, low carbohydrate (ketogenic) diet?
* Does a high-fat, low-carbohydrate diet, compared with a high-carbohydrate diet, prevent improvements in performance in the submaximal and maximal range?
* What is the effect of diets with different carbohydrate content and variable glycemic index on endurance performance in a half marathon and a time trial?
* How do the diets with different carbohydrate content and variable glycaemic index affect the energy and glycogen stores in the muscles?

In active recreational athletes, the objectives are: (1) to investigate the effects of different diets with variable carbohydrate content and glycaemic index on substrate metabolism, (2) to determine the effects of the different diets on energy stores using multinuclear dynamic magnetic resonance spectroscopy, and (3) to measure the effects of the different diets on endurance performance.

Detailed Description

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Conditions

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Substrate Metabolism During Exercise

Study Design

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Allocation Method

RANDOMIZED

Intervention Model

PARALLEL

Primary Study Purpose

BASIC_SCIENCE

Blinding Strategy

NONE

Study Groups

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Low GI

The subjects eat 55-60 E-% carbohydrates with ≥ 65 % from low glycaemic index carbohydrates per day, the other E-% are fats and proteins.

Group Type EXPERIMENTAL

Training intervention

Intervention Type OTHER

The training intervention will be a 10 week training plan for endurance runners. The plan consists of five sessions per week (three basic endurance sessions and two interval sessions)

Low Glycaemic Index

Intervention Type OTHER

The subjects eat 55-60 E-% carbohydrates with ≥ 65 % from low glycaemic index carbohydrates per day, the other E-% are fats and proteins.

High GI

The subjects eat 55-60 E-% carbohydrates with ≥ 65 % from high glycaemic index carbohydrates per day, the other E-% are fats and proteins.

Group Type ACTIVE_COMPARATOR

Training intervention

Intervention Type OTHER

The training intervention will be a 10 week training plan for endurance runners. The plan consists of five sessions per week (three basic endurance sessions and two interval sessions)

High Glycaemic Index

Intervention Type OTHER

The subjects eat 55-60 E-% carbohydrates with ≥ 65 % from high glycaemic index carbohydrates per day, the other E-% are fats and proteins.

Low Carb High Fat

The subjects eat ≥ 65 E-% fats and a maximum of 50 g carbohydrates per day.

Group Type EXPERIMENTAL

Training intervention

Intervention Type OTHER

The training intervention will be a 10 week training plan for endurance runners. The plan consists of five sessions per week (three basic endurance sessions and two interval sessions)

LCHF

Intervention Type OTHER

The subjects eat ≥ 65 E-% fats and a maximum of 50 g carbohydrates per day.

Interventions

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Training intervention

The training intervention will be a 10 week training plan for endurance runners. The plan consists of five sessions per week (three basic endurance sessions and two interval sessions)

Intervention Type OTHER

High Glycaemic Index

The subjects eat 55-60 E-% carbohydrates with ≥ 65 % from high glycaemic index carbohydrates per day, the other E-% are fats and proteins.

Intervention Type OTHER

LCHF

The subjects eat ≥ 65 E-% fats and a maximum of 50 g carbohydrates per day.

Intervention Type OTHER

Low Glycaemic Index

The subjects eat 55-60 E-% carbohydrates with ≥ 65 % from low glycaemic index carbohydrates per day, the other E-% are fats and proteins.

Intervention Type OTHER

Eligibility Criteria

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Inclusion Criteria

* Male gender
* Age between 18 and 40 years
* Recreational active in leisure time (2-3x/week physical activity)
* Motivation for performance testing and structured training plan
* Interest in different diets
* no acute or chronic illnesses

Exclusion Criteria

* Contraindications to physical exercise according to ACSM (American College of Sports Medicine) guidelines
* Age \<18 or \>40 years
* Taking medication that could influence the measurements or that is prohibited in training and/or competition according to the WADA (World Anti-Doping Agency) Code
* Competitive athlete with own training plan
* Experience with intervention diets


* Claustrophobia
* Cardiac pacemaker
* cochlear implant
* subcutaneous injection system
* Stents, metal implants, braces, piercings, tattoos
* Body weight of more than 180 kg or BMI of more than 37 kg/m2
Minimum Eligible Age

18 Years

Maximum Eligible Age

40 Years

Eligible Sex

MALE

Accepts Healthy Volunteers

Yes

Sponsors

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Medical University of Vienna

OTHER

Sponsor Role collaborator

University of Vienna

OTHER

Sponsor Role lead

Responsible Party

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Daniel König

Univ.-Prof. Dr. med., Head of Subunit Nutrition, Exercise and Health

Responsibility Role PRINCIPAL_INVESTIGATOR

Locations

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University of Vienna

Vienna, , Austria

Site Status

Countries

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Austria

References

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Moitzi AM, Krssak M, Klepochova R, Triska C, Csapo R, Konig D. Effects of a 10-Week Exercise and Nutritional Intervention with Variable Dietary Carbohydrates and Glycaemic Indices on Substrate Metabolism, Glycogen Storage, and Endurance Performance in Men: A Randomized Controlled Trial. Sports Med Open. 2024 Apr 10;10(1):36. doi: 10.1186/s40798-024-00705-9.

Reference Type DERIVED
PMID: 38600291 (View on PubMed)

Other Identifiers

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2105/2021

Identifier Type: -

Identifier Source: org_study_id