Impact of Sprint Stair Climbing Snacks on Markers of Metabolism and Vascular Function

Study Overview
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Brief Summary
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Prolonged sitting has been shown to impair metabolism and vascular function. The overall purpose of this study is to determine if breaking up prolonged (9 hours) of sitting with brief ( 20 second) stair climbing exercise snacks can improve markers of metabolic control and vascular health in healthy young male participants and in males or females with overweight/obesity who are at risk of insulin resistance. An additional purpose is to determine if saliva insulin can be used as a valid indicator of blood insulin when measured throughout the day in sedentary and active conditions and when diets with different amounts of carbohydrates are consumed.

Official Title
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Salivary Insulin Profiles Throughout the Day in Healthy Humans

Conditions
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Physical Activity, Diet Modification

Intervention / Treatment
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* Behavioral: High-Carbohydrate Sedentary
* Behavioral: High-Carbohydrate Active
* Behavioral: Low-carbohydrate Sedentary


Participation Criteria
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Eligibility Criteria
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Lean Group Inclusion Criteria: Non-smoking Lean Group Exclusion Criteria: Diagnosed with diabetes or prediabetes (fasting blood sugar more than 6.0 mmol/l) or any other chronic condition that may impact glucose or insulin levels. BMI is over 25 kg/m2 Take medications which may affect glucose and insulin levels Allergic to eggs. Smoker Competitive or serious endurance athlete. Overweight/Obese Group Inclusion Criteria: Elevated waist circumference (>102 cm for male and >88 cm for female) Overweight/Obese Group Exclusion Criteria: Diagnosed with diabetes (fasting blood sugar more than 7.0 mmol/l) Take medications which may affect glucose and insulin levels Allergic to eggs. Smoker Competitive or serious endurance athlete.

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 65 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: Other
Allocation: Randomized
Intervention Model: Crossover Assignment
Interventional Model Description: Participants complete three conditions in a repeated crossover design.
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: High-Carbohydrate Sedentary<br>Participants will remain seated for 9 hours (except for using the restroom) while consuming a high-carbohydrate diet (3 meals) | Behavioral: High-Carbohydrate Sedentary<br>* Three high-carbohydrate meals will be consumed (breakfast, lunch, and dinner) at  3 hour intervals while participants remain in a seated position for the entire 9 hour intervention period.<br>|
| Experimental: High-Carbohydrate Active<br>Participants will remain seated for 9 hours (except for using the restroom) while consuming a high-carbohydrate diet (3 meals) but will complete 8 stair climbing sprint snacks once per hour involving ascending 3 flights of stairs at a vigorous pace ( 20 seconds each). | Behavioral: High-Carbohydrate Active<br>* Three high-carbohydrate meals will be consumed (breakfast, lunch, and dinner) at  3 hour intervals while participants remain in a seated position for the entire 9 hour intervention period except that once every hour they will ascend three flights of stairs vigorously (stair climbing sprint snack) for a total of 8 active breaks.<br>|
| Active Comparator: Low-Carbohydrate Sedentary<br>Participants will remain seated for 9 hours (except for using the restroom) while consuming a low-carbohydrate diet (3 meals) | Behavioral: Low-carbohydrate Sedentary<br>* Three low-carbohydrate meals will be consumed (breakfast, lunch, and dinner) at  3 hour intervals while participants remain in a seated position for the entire 9 hour intervention period. This condition will provide a condition where the blood glucose and insulin responses are relatively low and stable throughout the day.<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Plasma insulin area under the curve | The plasma insulin concentration measured by enzyme-linked immunosorbent assay area under the curve will be measured using the trapezoidal rule. | Measured across 9 hours of each intervention day | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Saliva insulin area under the curve | The saliva insulin concentration measured by enzyme-linked immunosorbent assay area under the curve will be measured using the trapezoidal rule. | Measured across 9 hours of each intervention day | 
| Plasma glucose area under the curve | The plasma glucose concentration measured by hexokinase method area under the curve will be measured using the trapezoidal rule. | Measured across 9 hours of each intervention day | 
| Plasma triglyceride area under the curve | The plasma triglyceride concentration measured by biochemical assay area under the curve will be measured using the trapezoidal rule. | Measured across 9 hours of each intervention day | 
| Plasma non-esterified fatty acids area under the curve | The plasma non-esterified fatty acid concentration measured by biochemical assay area under the curve will be measured using the trapezoidal rule. | Measured across 9 hours of each intervention day | 
| Femoral artery flow-mediated dilation | Flow-mediated dilation of femoral artery measured by vascular ultrasound | Measured in the morning (time 0 hours) and afternoon (time 8.5 hours) each intervention day | 
| Cerebrovascular function | Cerebrovascular function measured by transcranial doppler ultrasound | Measured in the morning (time 0.5 hours) and afternoon (time 6 hours) each intervention day | 
| Cognitive function | Cognitive function measured by Computerized Neurocognitive Assessment Software (CNS) Vital Signs test battery | Measured in the morning (time 0.5 hours) and afternoon (time 6 hours) each intervention day |