Exercise in the Fasted State, Glucose Metabolism and Energy Balance

Study Overview
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Brief Summary
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The ability to control our blood glucose (sugar) concentrations after a meal is a strong predictor of the risk of disease. Our bodies respond to glucose ingestion by reducing the amount of glucose from the liver entering the bloodstream. At the same time muscle increases the amount of glucose it take up from the bloodstream. This ensures that our blood glucose levels do not get too high. The investigators want to understand what happens to these processes following exercise after breakfast and after an overnight fast. In addition, the investigators also want to understand whether exercising with or without breakfast influences our appetite, food intake and activity levels later in the day.

Conditions
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Blood Glucose, Energy Balance

Intervention / Treatment
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* Behavioral: Exercise
* Dietary Supplement: Breakfast


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Males. Aged 18-49. Individuals free from known cardiovascular, metabolic or joint disease as determined by standard health questionnaire. Habitual regularly participating in exercise (minimum of 3 sessions per week on average) Non-smoker Exclusion Criteria: Known or suspected food intolerances, allergies or hypersensitivity. Any bleeding disorder or taking medication which impacts blood coagulation. Known tendency towards keloid scarring. Known sensitivity or allergy to any local anaesthetic medicines. Any reported use of substances which may pose undue personal risk to participants or introduce bias into the experiment. Any other condition or behaviour deemed either to pose undue personal risk to participants or introduce bias into the experiment.

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 49 Years

Sexes Eligible for Study
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Male

Accepts Healthy Volunteers
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Accepts Healthy Volunteers

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Basic Science
Allocation: Randomized
Intervention Model: Crossover Assignment
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Active Comparator: Breakfast Rest<br> | Dietary Supplement: Breakfast<br>* Breakfast consumption<br>|
| Active Comparator: Breakfast Exercise<br> | Behavioral: Exercise<br>* Moderate intensity exercise<br>Dietary Supplement: Breakfast<br>* Breakfast consumption<br>|
| Experimental: Fasted Exercise<br> | Behavioral: Exercise<br>* Moderate intensity exercise<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Exogenous glucose appearance rate | Exogenous glucose appearance rates following an oral glucose tolerance test (total appearance over 120 minutes). | 120 minutes | 
| Energy balance | Energy balance (intake minus expenditure) over 24 h from the beginning of the trial | 24 hours | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Endogenous glucose appearance rates | Endogenous glucose appearance rates following an oral glucose tolerance test (total appearance over 120 minutes). | 120 minutes | 
| Glucose clearance rates | Glucose clearance rates following an oral glucose tolerance test (total clearance over 120 minutes). | 120 minutes | 
| Energy intake | Weighted energy intake over 24 hours from the beginning of the trial. | 24 h | 
| Energy expenditure | Energy expenditure, derived from indirect calorimetry, acccelerometry and heart rate monitoring. | 24 h | 
| Exogenous glucose appearance rates | Exogenous glucose appearance rates following an oral glucose tolerance test (total appearance over 120 minutes). | 120 minutes |