Interrupting Sitting With High Intensity Exercise on Vascular Function in Adolescents Before and After a Mixed Meal
- Conditions
- Endothelial DysfunctionCardiovascular Risk Factor
- Interventions
- Behavioral: Interrupting 3 hours of prolonged sitting with high intensity interval exerciseBehavioral: 3 hours of prolonged sitting
- Registration Number
- NCT04337385
- Lead Sponsor
- University of Exeter
- Brief Summary
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.
- 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.
Recruitment & Eligibility
- Status
- TERMINATED
- Sex
- All
- Target Recruitment
- 6
- Male and female adolescents
- 12-15 years
- 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 & Design
- Study Type
- INTERVENTIONAL
- Study Design
- CROSSOVER
- Arm && Interventions
Group Intervention Description 3 hours of interrupted sitting with hourly HIIE Interrupting 3 hours of prolonged sitting with high intensity interval exercise 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. 3 hours of Prolonged Sitting 3 hours of prolonged sitting Participants will sit continuously for three hours before receiving a mixed meal challenge.
- Primary Outcome Measures
Name Time Method Popliteal macrovascular function Before and after 3 hours of prolonged vs. interrupted sitting and after a subsequent 3 hour postprandial period Flow mediated dilation will be used to assess changes in microvascular function of the popliteal artery
- Secondary Outcome Measures
Name Time Method Calf circumference 6.5 hours 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
Sitting time during the experimental visits 6 hours Participants will wear an activPAL accelerometer on their thigh to quantify the amount of time they spend sitting, standing and cycling during the trials
Microvascular function in the capillaries of the calf Before and after 3 hours of prolonged vs. interrupted sitting and after a subsequent 3 hour postprandial period Microvascular function will be assessed using post occlusive reactive hyperaemia via laser Doppler flowmetry
Physical activity prior to the experimental visits 48 hours prior to each visit Participants will wear GENEactiv accelerometers to monitor their physical activity levels before the experimental visit
Changes in plasma insulin concentration from a capillary sample 6.5 hours Changes in plasma insulin concentration will be assessed in response to the prolonged or interrupted sitting and after mixed meal
Changes in plasma triglyceride concentration from a capillary sample 6.5 hours Changes in plasma triglyceride concentration will be assessed in response to the prolonged or interrupted sitting and after mixed meal
Changes in plasma glucose concentration from a capillary sample 6.5 hours Changes in plasma glucose concentration will be assessed in response to the prolonged or interrupted sitting and after mixed meal
Blood pressure 6.5 hours Changes in blood pressure will be monitored hourly throughout the 3 hour sitting period and three hour postprandial period
Heart rate 6.5 hours Changes in heart rate will be monitored hourly throughout the 3 hour sitting period and three hour postprandial period
Trial Locations
- Locations (1)
University of Exeter
🇬🇧Exeter, Devon, United Kingdom