Training in the Fasted State, Glucose Metabolism and Energy Balance

November 23, 2022 updated by: Javier Gonzalez, University of Bath

In healthy individuals, the body responds to glucose (sugar) ingestion by reducing the amount released from the liver. At the same time, skeletal muscles increase the rate at which they remove the glucose from the bloodstream, via the actions of the hormone insulin. This ensures that blood glucose levels remain in a controlled range. However, in developed countries, diseases such as metabolic syndrome and type 2 diabetes are becoming prevalent, due to dietary modifications and a reduction in physical activity. As one of the prominent barriers to regular physical activity is a lack of time, finding ways to maximize the health benefits of exercise is a priority for researchers.

The investigators want to understand potential differences in the effects of six weeks of aerobic training, with the exercise performed either after breakfast or after a prolonged fast. Specifically, this research aims to investigate whether there is a difference in the change in processes implicated in glucose regulation and secondly, in subsequent eating and physical activity behaviors. By investigating these changes this work will explore how exercise and nutrition can be optimized to benefit health and weight loss.

Study Overview

Study Type

Interventional

Enrollment (Actual)

30

Phase

  • 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 Locations

      • Bath, United Kingdom, BA2 7AY
        • Department for Health, University of Bath

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

Ages Eligible for Study

18 years to 49 years (Adult)

Accepts Healthy Volunteers

Yes

Genders Eligible for Study

Male

Description

Inclusion Criteria:

  • Male
  • Aged 18-49
  • Body mass index (BMI) > 25 kg/m2
  • Weight stable for > 6 months
  • Not currently engaging in any form of structured exercise
  • Be able and willing to give informed oral and written consent
  • Complete and meet the defined criteria of pre-study questionnaires and screen

Exclusion Criteria:

  • Have a history of metabolic, cardio-pulmonary or musculoskeletal disease
  • Have plans to change diet and/or physical activity outside of the intervention
  • Taking regular medication or food supplements from which it is not possible to refrain and which are known to influence any of the outcome measures.
  • Failure to refrain from alcohol and/or caffeine containing drinks or strenuous exercise one day before or during the trial days
  • Smokers
  • Any reported condition or behavior deemed to pose a risk to the participant or introduce bias into the experiment

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: Basic Science
  • Allocation: Randomized
  • Interventional Model: Parallel Assignment
  • Masking: None (Open Label)

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
Active Comparator: Control Group
Maintain habitual habits
Normal physical activity and dietary behaviors maintained
Active Comparator: Fed Exercise
6 weeks of moderate intensity exercise with breakfast consumption
Moderate intensity exercise
Breakfast consumption
Experimental: Fasted Exercise
6 weeks of moderate intensity exercise with breakfast omission
Moderate intensity exercise

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Postprandial plasma glucose concentrations
Time Frame: 120 mins - (change after 6 weeks)
Response to oral glucose tolerance test (area under the curve)
120 mins - (change after 6 weeks)
Postprandial insulin concentrations
Time Frame: 120 mins - (change after 6 weeks)
Response to oral glucose tolerance test (area under the curve)
120 mins - (change after 6 weeks)

Secondary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Oral Glucose Insulin Sensitivity Index
Time Frame: 120 mins - (change after 6 weeks)
Response to oral glucose tolerance test
120 mins - (change after 6 weeks)
Cardiorespiratory fitness (VO2max)
Time Frame: Change after 6 weeks
Change after 6 weeks
Habitual energy intake
Time Frame: Change after 6 weeks
Assessed via a food diary, completed at baseline and during the last week of the intervention
Change after 6 weeks
Habitual energy expenditure
Time Frame: Change after 6 weeks
Assessed via an Actiheart monitor, completed at baseline and during the last week of the intervention
Change after 6 weeks
Body mass (kg)
Time Frame: Change after 6 weeks
Change after 6 weeks
Waist and hip circumference (cm)
Time Frame: Change after 6 weeks
Change after 6 weeks
Maximal rate of whole-body lipid oxidation (g/min)
Time Frame: Change after 6 weeks
During an incremental exercise test
Change after 6 weeks
Fasting plasma glucose concentration
Time Frame: Basal Concentrations - (change after 6 weeks)
Fasting plasma glucose concentration (mmol/L)
Basal Concentrations - (change after 6 weeks)
Fasting plasma insulin concentration
Time Frame: Basal Concentrations - (change after 6 weeks)
Fasting plasma insulin concentration (pmol/L)
Basal Concentrations - (change after 6 weeks)
Postprandial non-esterified fatty acid concentrations
Time Frame: 120 mins - (change after 6 weeks)
Response to oral glucose tolerance test (total and incremental area under the curve)
120 mins - (change after 6 weeks)
Fasting plasma triglyceride concentrations
Time Frame: Basal Concentrations - (change after 6 weeks)
Fasting plasma triglyceride concentrations (mmol/L)
Basal Concentrations - (change after 6 weeks)
Fasting plasma total cholesterol concentrations
Time Frame: Basal Concentrations - (change after 6 weeks)
Fasting plasma total cholesterol concentrations (mmol/L)
Basal Concentrations - (change after 6 weeks)
Fasting plasma HDL cholesterol concentrations
Time Frame: Basal Concentrations - (change after 6 weeks)
Fasting plasma HDL cholesterol concentrations (mmol/L)
Basal Concentrations - (change after 6 weeks)
Fasting plasma LDL cholesterol concentrations
Time Frame: Basal Concentrations - (change after 6 weeks)
Fasting plasma LDL cholesterol concentrations (mmol/L)
Basal Concentrations - (change after 6 weeks)
Fasting plasma non-esterified fatty acid concentrations
Time Frame: Basal Concentrations - (change after 6 weeks)
Fasting plasma non-esterified fatty acid concentrations (mmol/L)
Basal Concentrations - (change after 6 weeks)
Waist to hip ratio
Time Frame: Change after 6 weeks
Waist circumference (cm) divided by hip circumference (cm)
Change after 6 weeks
Citrate Synthase Activity (mitochondrial citrate synthase activity in each muscle sample in an immunocapture based manner)
Time Frame: Change after 6 weeks
Skeletal muscle (vastus lateralis). Citrate Synthase Activity Assay Kit.
Change after 6 weeks
Protein content of mitochondrial respiratory chain proteins
Time Frame: Change after 6 weeks. For each participant the protein content will be presented as the fold change from baseline (arbitrary units).
Skeletal muscle (vastus lateralis). Complex I, Complex II, Complex III, Complex IV.
Change after 6 weeks. For each participant the protein content will be presented as the fold change from baseline (arbitrary units).
Protein content of carnitine palmitoyltransferase I (CPT-1)
Time Frame: Change after 6 weeks. For each participant the protein content will be presented as the fold change from baseline (arbitrary units)
Skeletal muscle (vastus lateralis)
Change after 6 weeks. For each participant the protein content will be presented as the fold change from baseline (arbitrary units)
Protein content of cluster of differentiation 36 (CD36)
Time Frame: Change after 6 weeks. For each participant the protein content will be presented as the fold change from baseline (arbitrary units)
Skeletal muscle (vastus lateralis)
Change after 6 weeks. For each participant the protein content will be presented as the fold change from baseline (arbitrary units)
Protein content (total and phosphorylated form) of AMP-activated protein kinase (AMPK)
Time Frame: Change after 6 weeks. For each participant the protein content will be presented as the fold change from baseline (arbitrary units)
Skeletal muscle (vastus lateralis)
Change after 6 weeks. For each participant the protein content will be presented as the fold change from baseline (arbitrary units)
Resting metabolic rate (RMR)
Time Frame: Change after 6 weeks
Assessed via indirect calirometry
Change after 6 weeks
Energy balance
Time Frame: Change after 6 weeks (during week 6 of intervention versus baseline monitoring)
Total energy expenditure minus total energy intake
Change after 6 weeks (during week 6 of intervention versus baseline monitoring)
Whole-body lipid utilisation during exercise
Time Frame: Change throughout complete training period (weeks 1 through to 6). Samples will be collected during every training session (three times weekly for six weeks)
Assessed via indirect calirometry during every exercise session (at ten minute intervals)
Change throughout complete training period (weeks 1 through to 6). Samples will be collected during every training session (three times weekly for six weeks)
Whole-body carbohydrate utilisation during exercise
Time Frame: Change throughout complete training period (weeks 1 through to 6). Samples will be collected during every training session (three times weekly for six weeks)
Assessed via indirect calirometry during every exercise session (at ten minute intervals)
Change throughout complete training period (weeks 1 through to 6). Samples will be collected during every training session (three times weekly for six weeks)
Homeostasis Model Assessment (HOMA2-IR)
Time Frame: Change after 6 weeks
The Homeostasis Model Assessment (HOMA) estimate of steady state beta cell function (%B) and insulin sensitivity (%S). Derived from fasting plasma glucose and fasting plasma insulin concentrations.
Change after 6 weeks
Fasting plasma glycerol concentrations
Time Frame: Basal Concentrations - (change after 6 weeks)
Fasting plasma glycerol concentrations (mmol/L)
Basal Concentrations - (change after 6 weeks)
Postprandial plasma glycerol concentrations
Time Frame: Change after 6 weeks
Response to oral glucose tolerance test (total and incremental area under the curve)
Change after 6 weeks
Adipose Tissue Insulin Resistance Index (Adipo-IR)
Time Frame: Change after 6 weeks
Response to oral glucose tolerance test (total and incremental area under the curve)
Change after 6 weeks

Collaborators and Investigators

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

Investigators

  • Principal Investigator: Javier Gonzalez, PhD, University of Bath

Publications and helpful links

The person responsible for entering information about the study voluntarily provides these publications. These may be about anything related to the study.

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)

October 1, 2016

Primary Completion (Actual)

August 1, 2018

Study Completion (Actual)

September 1, 2019

Study Registration Dates

First Submitted

April 11, 2016

First Submitted That Met QC Criteria

April 15, 2016

First Posted (Estimate)

April 20, 2016

Study Record Updates

Last Update Posted (Actual)

November 25, 2022

Last Update Submitted That Met QC Criteria

November 23, 2022

Last Verified

November 1, 2022

More Information

Terms related to this study

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

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.

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