None listed
Conditions
Brief summary
This study will provide important evidence around how reducing sedentary behaviour by standing, or performing short bouts of activity regularly may improve postprandial metabolism and endothelial function, both of which are important for cardio-metabolic health. We will conduct a randomised cross-over study involving 18 healthy, normal weight participants. The study will include three experimental intervention sessions: prolonged sitting; prolonged standing; and regular activity breaks, each separated by a minimum six-day washout period. Flow-mediated dilation will be measured at baseline, and at the conclusion of each intervention, while popliteal artery haemodynamics will be measured hourly to assess changes in blood flow and shear stress. Area under the curve will be calculated for plasma glucose and insulin. Mixed model regression will be used to examine differences in the effect of the three different interventions on markers of endothelial function and postprandial metabolism.
Interventions
Participants will complete, in a random order, two intervention session and one control session. Each session will be separated by six days.
The two intervention sessions are as follows:
1) Regular activity breaks: Participants will walk on the treadmill at 5 km/h for 2 min every 30 min throughout the 6.5 h intervention session. At all other times they will remain seated
2) Continuous standing: Participants will stand at a standing desk continuously throughout the 6.5 h session.
The control
Participants will complete, in a random order, two intervention session and one control session. Each session will be separated by six days. The two intervention sessions are as follows: 1) Regular activity breaks: Participants will walk on the treadmill at 5 km/h for 2 min every 30 min throughout the 6.5 h intervention session. At all other times they will remain seated 2) Continuous standing: Participants will stand at a standing desk continuously throughout the 6.5 h session. The control session is: Continuous sitting, in which the participant will remain seated for the duration of the session. During each intervention/control session participants will be fed a standardised breakfast (of Muesli, milk, toast, margarine, honey and juice providing 106 g of carbohydrate and 13 g fat) at 45 min, and a standardised snack (chocolate brownie, providing 44 g carbohydrate and 17 g fat) at 240 min. Investigators will be in the laboratory with participants at all times to ensure compliance to these procedures
Sponsors
Meredith Peddie
Study design
Allocation
Randomised controlled trial
Intervention model
Crossover
Primary purpose
Prevention
Masking
Blinded (masking used) (Investigator, Outcomes Assessor)
Eligibility
Sex/Gender
All
Age
18 Years to 40 Years
Healthy volunteers
Yes
Inclusion criteria
Healthy men and women who self report spending greater than 5 h per day, on average, engaged in sedentary behaviour, and who do not use a sit to stand work station or standing desk on a regular basis.
Exclusion criteria
personal history of cardiovascular disease or diabetes, current smoker, BMI greater than 35 kg/m2, taking any medication, dietary supplements, vitamins or minerals, other than hormonal contraceptive agents, contraindications for participating in phsical activity or standing for long periods, intolerance/allergy to dairy of gluten
Outcome results
None listed