The purpose of this study is to determine whether acute bouts of sedentary behaviour (with or without breaks and/or structured physical activity) result in measurable changes in metabolic health in children and youth.

The Metabolic Effects of Breaks in Sedentary Time

Feasibility

Insulin

Glucose

Lipids

Eating

North American children spend the majority of their waking hours engaging in sedentary behavior (e.g. sitting). Research in adults and animal models suggests that even short bouts of uninterrupted siting may result in acute changes increases in cardiometabolic risk, although to date no studies have investigated this relationship in children and youth. The purpose of this study is to assess the feasibility of a protocol which will expose participants aged 10-14 years to a full day of uninterrupted sitting, and to determine the impact of this protocol on markers of cardiometabolic risk (insulin, glucose, triglyceride, HDL-C and LDL-C) as well as subsequent food intake and physical activity. The impact of uninterrupted sitting will be compared to the impact of interrupted sitting, with and without the inclusion of moderate physical activity.

Sedentary

Sedentary With Breaks

Sedentary With Breaks and Physical Activity

Insulin levels will be assessed multiple times throughout the day, and the resulting values will be used to calculate AUC.

Dr Mark Tremblay, Director, Healthy Active Living and Obesity Research Group

Blood draws will be taken several times throughout the day, and the resulting values will be used to calculate AUC.

Blood draws will occur throughout the day, and the resulting values will be used to calculate AUC.

In this condition, participants will engage in 8 hours of uninterrupted sedentary behaviour.

In this condition participants will engage in 8 hours of sitting, although the sitting will be interrupted every 20 minutes. During these interruptions participants will spend 2 minutes walking at an intensity equivalent to 30% of VO2peak.

In this condition participants will engage in 8 hours of sitting, although the sitting will be interrupted every 20 minutes. During these interruptions participants will spend 2 minutes walking at an intensity equivalent to 30% of VO2peak. Participants will also engage in 20 minutes of structured physical activity at an intensity of 60% of VO2peak in both the morning and afternoon.

Behavioural Metabolic Research Unit, University of Ottawa

In this condition, participants will engage in 8 hours of uninterrupted sedentary behaviour.

Sedentary: In this condition, participants will engage in 8 hours of uninterrupted sedentary behaviour.

In this condition participants will engage in 8 hours of sitting, although the sitting will be interrupted every 20 minutes. During these interruptions participants will spend 2 minutes walking at an intensity equivalent to 30% of VO2peak.

Sedentary With Breaks: In this condition participants will engage in 8 hours of sitting, although the sitting will be interrupted every 20 minutes. During these interruptions participants will spend 2 minutes walking at an intensity equivalent to 30% of VO2peak.

In this condition participants will engage in 8 hours of sitting, although the sitting will be interrupted every 20 minutes. During these interruptions participants will spend 2 minutes walking at an intensity equivalent to 30% of VO2peak. Participants will also engage in 20 minutes of structured physical activity at an intensity of 60% of VO2peak in both the morning and afternoon.

Sedentary With Breaks and Physical Activity: In this condition participants will engage in 8 hours of sitting, although the sitting will be interrupted every 20 minutes. During these interruptions participants will spend 2 minutes walking at an intensity equivalent to 30% of VO2peak. Participants will also engage in 20 minutes of structured physical activity at an intensity of 60% of VO2peak in both the morning and afternoon.

All participants experienced all 3 conditions, in random order.

All Study Participants

Age, Categorical

Age, Continuous

Sex: Female, Male

Race and Ethnicity were not collected from any participant.

Race and Ethnicity Not Collected

Canada

Region of Enrollment

Body Mass Index calculated using height and weight

Waist circumference measured in cm

Tanner stages are a scale of physical development in children, adolescents and adults. The scale ranges from 1 (pre-pubescent child) to 5 (adult), and defines physical measurements of development based on external primary and secondary sex characteristics, such as the size of the breasts, genitals, testicular volume and development of pubic hair.

Pubertal stage measured by self-reported Tanner stage

Baseline PA level by Actical Accelerometer

Baseline Sedentary Behaviour by Actical Accelerometer

LDL-Cholesterol

HDL-Cholesterol

Triglycerides

Dr. Travis Saunders

Change in Insulin Net Incremental Area-Under-The-Curve (iAUC)

Change in Triglyceride Net Incremental Area-Under-The-Curve (iAUC)

Change in HDL-Cholesterol (HDL-C) Net Incremental Area-Under-The-Curve (iAUC)

Change in LDL-Cholesterol (LDL-C) Net Incremental Area-Under-The-Curve (iAUC)

Change in Glucose Net Incremental Area-Under-The-Curve (iAUC)

In this condition, participants experienced the experimental conditions in the following order. Each condition was separated by at least 1 week.

Sedentary condition

Sedentary with breaks condition

Sedentary with breaks and physical activity condition

Sed, Sed With Breaks, Sed With Breaks and PA

In this condition, participants experienced the experimental conditions in the following order. Each condition was separated by at least 1 week.

Sedentary condition

Sedentary with breaks and physical activity condition

Sedentary with breaks condition

Sed, Sed With Breaks and PA, Sed With Breaks

In this condition, participants experienced the experimental conditions in the following order. Each condition was separated by at least 1 week.

Sedentary with breaks and physical activity condition

Sedentary with breaks condition

Sedentary condition

Sed With Breaks, Sed With Breaks and PA, Sed

In this condition, participants experienced the experimental conditions in the following order. Each condition was separated by at least 1 week.

Sedentary with breaks condition

Sedentary condition

Sedentary with breaks and physical activity condition

Sed With Breaks, Sed, Sed With Breaks and PA

In this condition, participants experienced the experimental conditions in the following order. Each condition was separated by at least 1 week.

Sedentary with breaks and physical activity condition

Sedentary condition

Sedentary with breaks condition

The Metabolic Effects of Breaks in Sedentary Time

About this trial

Study ID

Status

Type

Phase

Placebo

Accepting

Trial Timing

What is this trial about?

What are the participation requirements?