Effect of Post-exercise Nutrition on Glycemia in Women

Study Overview
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Brief Summary
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The purpose of this study is to assess whether post-exercise Greek yogurt following a single session of aerobic exercise improves metabolic and musculoskeletal health in women with overweight/obesity.

Detailed Description
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Following the acquisition of informed consent, eligibility to participate in the study will be determined using questionnaires. Participants will undergo baseline testing at our laboratory at the University of Toronto to determine cardiorespiratory fitness, body composition and undergo exercise familiarization. Eligible participants will be assigned, in a random order, to two metabolic trials approximately 4 weeks apart that involve 4 days of controlled diet and exercise. Each trial takes place over 4 days, but participants are not required to come to the laboratory on all days. The two trials involve: 1) Exercise + Greek Yogurt (GY) 2) Exercise + a carbohydrate-based study supplement (SS). During the 4 day trials, participants consume controlled diets and the study supplements (GY and SS). On 1 of these days participants will perform exercise in our lab followed by the consumption of GY or SS. Various outcomes will be measured throughout the trial, including glycemic control (via continuous glucose monitoring), fat oxidation, appetite and health outcomes in blood samples. Throughout the duration of the study, participants will be asked to maintain their habitual diet and physical activity patterns, and maintain their current body weight.

Official Title
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Influence of Post-exercise Greek Yogurt on 24 h Glycemic Control in Women With Overweight/Obesity

Conditions
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Overweight and Obesity

Intervention / Treatment
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* Behavioral: Greek yogurt
* Behavioral: Carbohydrate-based study supplement
* Behavioral: Exercise


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: 18-45 yrs BMI ≥27 kg/m2 Elevated waist circumference (≥88 cm) ≤2 structured exercise sessions/week Weight stable (within ± 2kg for at least 6 months) Experiencing regular natural menstrual cycles Non-smoker Exclusion Criteria: Allergy to dairy foods Diagnosed lactose intolerance or an aversion to foods provided during the study (e.g., post-exercise snacks) Previous history of cardiovascular or metabolic disease The use of medication for managing blood glucose or lipid metabolism Current use of oral contraceptives or use within the last 3 months Irregular menstrual cycles (<21 days or >35 days) Pregnant or lactating Recreational tobacco or cannabis use Inability to perform the study exercise protocols Actively engaging in a low-carbohydrate diet (e.g., ketogenic, Atkins).

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

Sexes Eligible for Study
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Female

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: Treatment
Allocation: Randomized
Intervention Model: Crossover Assignment
Masking: Double


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: High-intensity interval exercise and post-exercise Greek yogurt (HIIE+GY)<br>Participants will consume greek yogurt following a single session of exercise | Behavioral: Greek yogurt<br>* Following 2 days of controlled diet, participants will consume greek yogurt following high-intensity interval exercise<br>Behavioral: Exercise<br>* Following 2 days of controlled diet, participants will perform high-intensity interval exercise following an overnight fast<br>|
| Active Comparator: High-intensity interval exercise and post-exercise carbohydrate study supplement (HIIE +SS)<br>Participants will consume a carbohydrate-based study supplement following a single session of exercise | Behavioral: Carbohydrate-based study supplement<br>* Following 2 days of controlled diet, participants will consume a carbohydrate-based study supplement following high-intensity interval exercise<br>Behavioral: Exercise<br>* Following 2 days of controlled diet, participants will perform high-intensity interval exercise following an overnight fast<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Postprandial glycemia | Postprandial glucose exposure assessed using continuous glucose monitoring | 24 hour post-exercise | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| 24 hours average glucose | Average glucose concentration over 24 hours | 24 hours post-exercise | 
| Nocturnal glucose | Overnight glucose concentration | 6-8 hours | 
| Nocturnal glucose | Overnight glucose exposure (area under the curve) | 6-8 hours | 
| Glycemic variability | Continuous overall net glycemic action (CONGA) | 24 hours | 
| Glycemic variability | Standard deviation (SD) | 24 hours | 
| Glycemic variability | Coefficient of variation (%CV) | 24 hours | 
| Post-exercise fat oxidation | Fat oxidation assessed with indirect calorimetry | 1, 2 and 3 hours post-exercise | 
| Fasting glucose concentration | Venous blood sampling | 24 hours post-exercise | 
| Fasting insulin concentration | Venous blood sampling | 24 hours post-exercise | 
| Fasting insulin resistance | Homeostasis Model Assessment (HOMA2) | 24 hours post-exercise | 
| Bone metabolism | Serum concentration of CTX | 30, 90, and 180 minutes and 24 hours post-exercise | 
| Bone metabolism | Serum concentration of OPG | 30, 90, and 180 minutes and 24 hours post-exercise | 
| Bone metabolism | Serum concentration of RANKL | 30, 90, and 180 minutes and 24 hours post-exercise | 
| Bone metabolism | Serum concentration of OC | 30, 90, and 180 minutes and 24 hours post-exercise | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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women, glycemic control, exercise