Galactose Mediated Glycogen Resynthesis

Study Overview
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Brief Summary
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This study will compare short-term post-exercise muscle glycogen synthesis following combined galactose-glucose, glucose alone or galactose alone ingestion.

Detailed Description
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Lactose, the sugar contained within milk, consists of glucose and galactose. Post-exercise consumption of a carbohydrate mixture containing glucose with galactose has been shown to accelerate liver glycogen repletion as compared to glucose-only provision. However, the extent to which galactose-glucose combinations influence post-exercise muscle glycogen storage has yet to be determined. Therefore, this study will investigate whether short-term muscle glycogen storage after strenuous endurance exercise is enhanced by combined galactose-glucose or glucose only ingestion as compared to the ingestion of galactose alone.

Official Title
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Galactose Mediated Glycogen Resynthesis and the Effects on Metabolism During Subsequent Exercise

Conditions
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Exercise

Intervention / Treatment
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* Other: Glucose alone
* Other: Galactose alone
* Other: Glucose and galactose


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria:. Body mass index in the range: 18.5 - 27.5 kg/m2 Participates in endurance-based exercise (e.g. cycling, running, rowing) at least 3 times per week Aerobic fitness: VO2max >45 ml/kg/min (men), >40 ml/kg/min (women) Exclusion Criteria: Lidocaine allergy Current participation in another scientific/clinical study Bleeding disorder/s Current or recent smoker to include vaping (last 60 days) Vegan Existence of food intolerances Poor recent health as indicated in the general health questionnaire Engage in uncommon eating practices (e.g. sustained periods of fasting) Diagnosed with galactosemia

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 45 Years

Sexes Eligible for Study
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All

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: Double


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Glucose alone<br>Participants will complete a glycogen depleting bout of exercise followed by the provision of glucose-alone over 4 hours of recovery before a subsequent bout of exercise. | Other: Glucose alone<br>* Young men or women will complete a glycogen depleting bout of exercise followed by the provision of glucose-alone over 4 hours of recovery before a subsequent bout of exercise.<br>|
| Experimental: Galactose alone<br>Participants will complete a glycogen depleting bout of exercise followed by the provision of galactose-alone over 4 hours of recovery before a subsequent bout of exercise. | Other: Galactose alone<br>* Young men or women will complete a glycogen depleting bout of exercise followed by the provision of galactose-alone over 4 hours of recovery before a subsequent bout of exercise.<br>|
| Experimental: Glucose and galactose<br>Participants will complete a glycogen depleting bout of exercise followed by the provision of glucose and galactose over 4 hours of recovery before a subsequent bout of exercise. | Other: Glucose and galactose<br>* Young men or women will complete a glycogen depleting bout of exercise followed by the provision of glucose and galactose over 4 hours of recovery before a subsequent bout of exercise.<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Muscle glycogen synthesis rates (mmol/kg/dm/h) | Muscle glycogen synthesis rates over the post-exercise recovery period | 4 hours | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Carbohydrate oxidation rates (g/min) | Total, exogenous and endogenous carbohydrate oxidation during a secondary bout of exercise | Up to 90 minutes | 
| Fat oxidation rates (g/min) | Fat oxidation during a secondary bout of exercise | Up to 90 minutes | 
| Plasma glucose (mmol/L) | Plasma glucose during the post-exercise recovery period and during a secondary bout of exercise | Up to 6 hours | 
| Serum insulin (mU/L) | Serum insulin during the post-exercise recovery period and during a secondary bout of exercise | Up to 6 hours | 
| Plasma galactose (mmol/L) | Plasma galactose during the post-exercise recovery period and during a secondary bout of exercise | Up to 6 hours | 
| Plasma lactate (mmol/L) | Plasma lactate during the post-exercise recovery period and during a secondary bout of exercise | Up to 6 hours | 
| Plasma non-esterified fatty acids (mmol/L) | Plasma non-esterified fatty acids during the post-exercise recovery period and during a secondary bout of exercise | Up to 6 hours | 
| Plasma glycerol (umol/L) | Plasma glycerol during the post-exercise recovery period and during a secondary bout of exercise | Up to 6 hours | 
| Plasma glucagon (pmol/L) | Plasma glucagon during the post-exercise recovery period and during a secondary bout of exercise | Up to 6 hours |