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
Trial Snapshot
- Phase
- Not Applicable
- Status
- Terminated
- Sponsor
- University of Exeter
- Enrollment
- 6
- Locations
- 1
- Primary Endpoint
- Popliteal macrovascular function
Study Overview
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.
Study Design
- Study Type
- Interventional
- Allocation
- Non Randomized
- Intervention Model
- Crossover
- Primary Purpose
- Basic Science
- Masking
- None
Eligibility Criteria
- Ages
- 12 Years to 15 Years (Child)
- Sex
- All
- Accepts Healthy Volunteers
- Yes
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
Arms & Interventions
3 hours of Prolonged Sitting
Participants will sit continuously for three hours before receiving a mixed meal challenge.
Intervention: 3 hours of prolonged sitting (Behavioral)
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.
Intervention: Interrupting 3 hours of prolonged sitting with high intensity interval exercise (Behavioral)
Outcomes
Primary Outcomes
Popliteal macrovascular function
Time Frame: 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 Outcomes
- Changes in plasma insulin concentration from a capillary sample(6.5 hours)
- Changes in plasma triglyceride concentration from a capillary sample(6.5 hours)
- Calf circumference(6.5 hours)
- Changes in plasma glucose concentration from a capillary sample(6.5 hours)
- 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)
- Physical activity prior to the experimental visits(48 hours prior to each visit)
- Blood pressure(6.5 hours)
- Heart rate(6.5 hours)
- Sitting time during the experimental visits(6 hours)