Interrupting Sitting With High Intensity Exercise on Vascular Function in Adolescents Before and After a Mixed Meal

The Effect of Prolonged vs. Interrupted Sitting With High Intensity Interval Exercise on Lower Limb Vascular Function in Adolescents Before and After a Mixed Meal

This study aims to investigate the effect of interrupting a three hour bout of prolonged sitting with high intensity interval exercise on lower limb blood vessel function in adolescents before and after a mixed meal challenge.

Study Overview

• Status: Terminated
• Conditions: Endothelial Dysfunction; Cardiovascular Risk Factor
• Intervention / Treatment: Behavioral: 3 hours of prolonged sitting; Behavioral: Interrupting 3 hours of prolonged sitting with high intensity interval exercise

Detailed Description

Participants will be required to visit the laboratory on three separate occasions. The first of which will be a preliminary visit to collect anthropometric data (e.g. stature and body weight) and participants will complete a combined ramp-incremental and supra-maximal test to exhaustion on a cycle ergometer to determine the work rate for the exercise in the subsequent experimental visits.

For the two experimental visits, participants will arrive to the laboratory after an overnight fast and an activPAL accelerometer will be attached to the midline of the participants' thigh for the duration of the visit to quantity sitting time.

Lower limb macro and micro-vascular function will be assessed using a single protocol through flow mediated dilation of the popliteal artery and post-occlusive reactive hyperaemia in the capillaries of the calf. Participants will then either sit for three hours or have this three hour sitting period interrupted with high intensity interval cycling exercise at 30, 90 and 150 minutes. Vascular function will then be reassessed before participants will be given a mixed meal challenge (58.4 g fat and 53.4 g sugar) with a three hour postprandial period where the participants will remain seated for the duration. At the end of the postprandial period, vascular function will be reassessed.

Blood pressure, heart rate and calf circumference will be assessed hourly throughout the experimental day. In addition, capillary blood samples will be collected at baseline, pre meal and each hour during the postprandial period and assessed for changes in plasma glucose, triglyceride, cholesterol and insulin concentrations.

Participants will be transported to the toilet by wheelchair to limit the amount of walking undertaken during the sitting period and this activity will be quantified by the activPAL accelerometers.

• Study Type: Interventional
• Enrollment (Actual): 6
• Phase: Not Applicable

Contacts and Locations

Study Locations

• United Kingdom
  • Devon
    • Exeter, Devon, United Kingdom, EX1 2LU
      • University of Exeter

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 12 years to 15 years (Child)
• Accepts Healthy Volunteers: No
• Genders Eligible for Study: All

Description

Inclusion Criteria:

• Male and female adolescents
• 12-15 years

Exclusion Criteria:

• Medications known to affect blood pressure, carbohydrate or fat metabolism
• Allergies to the test meal e.g. dairy or gluten
• Contraindications to exercise
• Individuals with special educational needs that mean they are unable to fully comprehend the demands of the study procedures

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Basic Science
• Allocation: Non-Randomized
• Interventional Model: Crossover Assignment
• Masking: None (Open Label)

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: 3 hours of Prolonged Sitting; Participants will sit continuously for three hours before receiving a mixed meal challenge.	Behavioral: 3 hours of prolonged sitting; Participants will be asked to remain seated for 3 hours and refrain from moving their lower limbs
Experimental: 3 hours of interrupted sitting with hourly HIIE; Participants will have their three hour sitting period interrupted with high intensity interval cycling exercise (HIIE) at 30, 90 and 150 minutes into the intervention. In each exercise bout, they will cycle at 90% peak power for 3 x 60 second periods with 75 seconds of recovery in-between.	Behavioral: Interrupting 3 hours of prolonged sitting with high intensity interval exercise; Breaking up a prolonged bout of sitting in adolescents using high intensity interval exercise

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Popliteal macrovascular function	Flow mediated dilation will be used to assess changes in microvascular function of the popliteal artery	Before and after 3 hours of prolonged vs. interrupted sitting and after a subsequent 3 hour postprandial period

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Microvascular function in the capillaries of the calf	Microvascular function will be assessed using post occlusive reactive hyperaemia via laser Doppler flowmetry	Before and after 3 hours of prolonged vs. interrupted sitting and after a subsequent 3 hour postprandial period
Changes in plasma triglyceride concentration from a capillary sample	Changes in plasma triglyceride concentration will be assessed in response to the prolonged or interrupted sitting and after mixed meal	6.5 hours
Changes in plasma insulin concentration from a capillary sample	Changes in plasma insulin concentration will be assessed in response to the prolonged or interrupted sitting and after mixed meal	6.5 hours
Changes in plasma glucose concentration from a capillary sample	Changes in plasma glucose concentration will be assessed in response to the prolonged or interrupted sitting and after mixed meal	6.5 hours
Blood pressure	Changes in blood pressure will be monitored hourly throughout the 3 hour sitting period and three hour postprandial period	6.5 hours
Heart rate	Changes in heart rate will be monitored hourly throughout the 3 hour sitting period and three hour postprandial period	6.5 hours
Calf circumference	Calf circumference will be monitored every hour throughout experimental visit to give an indication of venous pooling that may occur as a result of the prolonged sitting and be implicated in the potential decline in vascular function	6.5 hours
Physical activity prior to the experimental visits	Participants will wear GENEactiv accelerometers to monitor their physical activity levels before the experimental visit	48 hours prior to each visit
Sitting time during the experimental visits	Participants will wear an activPAL accelerometer on their thigh to quantify the amount of time they spend sitting, standing and cycling during the trials	6 hours

Other Outcome Measures

Outcome Measure	Measure Description	Time Frame
Participant Enjoyment During the High Intensity Interval Exercise	The enjoyment of the high intensity interval exercise will be assessed during the exercise bouts using the Exercise Enjoyment Scale (ESS) (Stanley & Cumming, 2010). The scale runs from 1 (not at all) to 7 (extremely) so a larger score indicates greater enjoyment.	3 hours
Participant Enjoyment Post the High Intensity Interval Exercise	Participants will rate their enjoyment post exercise using the Physical Activity Enjoyment Scale (PACES) modified for adolescents (Motl et al., 2001). Participants rate how much they agree (1 = "disagree a lot" to 5 = "agree a lot") with 16 statements about their feelings from the exercise. The combined enjoyment scale score can range from 16 to 80 with a higher score indicating greater perceived enjoyment.	3 hours

Collaborators and Investigators

• Sponsor: University of Exeter
• Collaborators: University of British Columbia
• Investigators: Principal Investigator: Alan Barker, PhD, University of Exeter

Study record dates

Study Major Dates

• Study Start (Actual): March 4, 2020
• Primary Completion (Actual): March 13, 2020
• Study Completion (Actual): March 13, 2020

Study Registration Dates

• First Submitted: March 30, 2020
• First Submitted That Met QC Criteria: April 3, 2020
• First Posted (Actual): April 7, 2020

Study Record Updates

• Last Update Posted (Actual): May 25, 2021
• Last Update Submitted That Met QC Criteria: May 20, 2021
• Last Verified: May 1, 2021

More Information

Terms related to this study

• Keywords: Physical inactivity; Endothelial function; Paediatrics; Flow mediated dilation; Reactive hyperaemia
• Other Study ID Numbers: 191204/B/04

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No