Effects of Breaking up Prolonged Sitting on Postprandial Cardiometabolic Disease Risk Markers in Normal Weight Versus Overweight and Obese South Asian Adults
Phase: NA
Conditions: Cardiovascular Risk Factor, Cardiovascular Diseases, Diabetes, Physical Activity, Sedentary Lifestyle
Sponsor: University of Bedfordshire

1 
 
 
Unique Protocol ID: 
2019ISPAR003 
NCT Number: NCT03898206 
Date of Approval: 26th February 2019 
Date of Compilation: 30th December 2025 
Please note: All information is provided based on the pre-approved ethics, approved on 26th Feb 2019 
(approval confirmation attached at the end of this document).  
 
 
Study title: Effects of Breaking up Prolonged Sitting on Postprandial Cardiometabolic Disease Risk 
Markers in Normal Weight Versus Overweight and Obese South Asian Adults   
 
Brief Title: Effects of Breaking up Prolonged Sitting on Postprandial Cardiometabolic Disease Risk 
Markers in South Asian Adults   
 
 
 
Study aim: 
 
 
 
The purpose of this study is to examine whether breaking up prolonged sitting with short regular bouts of 
walking can reduce blood sugar and cholesterol levels after eating, which are risk markers for Type 2 
diabetes and heart disease. This study will compare these responses in normal-weight versus 
overweight/obese South Asian adults. 
 
 
Methods 
Study overview 
This two-condition randomised crossover study was conducted according to the Declaration of Helsinki 
principles and approved by the University of Bedfordshire Institute for Sport and Physical Activity 
Research Ethics Committee (2019ISPAR003). Participants provided written informed consent prior to 
taking part in any study procedures. The study was conducted and reported in line with the Consolidated 
Standards of Reporting Trials (CONSORT) guidance (Moher et al. 2012); see checklist in Supplementary 
Material S1. The trial was registered with clinicaltrials.gov/ (NCT03898206). Experimental condition 
order 
was 
randomised 
using 
an 
online 
computer-generated 
randomisation 
method 
(https://www.randomizer.org/). Following a preliminary testing visit, participants completed two 
experimental conditions separated by ≥ 3 to 28 days to eliminate potential carryover effects (Mikines et 
al. 1988). Female participants were tested between 1 and 10 days into their follicular phase to minimise 
the influence of hormonal fluctuations on glucose metabolism (Pulido and Salazar 1999). The study was 
interrupted by the COVID-19 pandemic, affecting the ability to continue data collection; the associated 
impact on the study protocol is described below. All testing procedures took place at the University of 
Bedfordshire Sport and Exercise Science Laboratories. 
 
Participants 
South Asian adults aged 18 to 75 years who were normal-weight (BMI 18.0–22.90 kg.m−2) or 
overweight/obese (BMI > 23 kg.m−2) were eligible to take part. These BMI thresholds were used in line 
with recommendations for South Asian populations (Bays et al. 2022). Body mass index was calculated 
as body mass (kg) ÷ height (m)2. ‘South Asian’ was defined as anyone identifying themselves as South 
Asian or British South Asian (Bays et al. 2022). Exclusion criteria were self-reported CVD, diabetes, any 
known blood borne disease, pregnancy, recent or current smoker, allergies to the test meals, other known 
health issues (e.g., neurological disorders), or any injuries that might limit the ability to perform light 
walking. Participants were recruited from the local community (Luton and Bedford, UK) using adverts 
through social media posts (e.g., Facebook and Twitter) and distribution of flyers. 
 
Preliminary measures 
Height (cm) was measured to the nearest 0.1 cm using a stadiometer (Harpenden 98.602, Crymych, UK). 
Body mass (kg) was measured to the nearest 0.1 kg, and the percentage of body fat (BF %) was estimated 

2 
 
 
after fasting for 4 h, using the Tanita BC-418 Segmental Body Composition Analyzer (Tanita Corp., 
Tokyo, Japan). Waist circumference (cm) was measured at minimal inspiration to the nearest 0.1 cm 
(Lohman et al. 1988). Resting blood pressure (BP; mmHg) and heart rate (HR; beats.min−1) were 
measured using an automatic device (Omron M5-I; Omron Matsusaka Co. Ltd., Matsusaka, Japan). 
Participants were familiarised with the Borg Rating of Perceived Exertion (RPE) scale (Borg 1982) and 
the Woodway motorised treadmill (Woodway PPS55Med-i, GmbH, Germany). An exercise protocol to 
determine the walking speed for each participant in the relevant experimental condition began at a speed 
of 1.2 km.h−1 and increased by 0.5 km.h−1 every 2-min until an RPE of 9 (very light) was reached. This 
speed was recorded for each participant (Bailey and Locke 2015). 
 
Experimental protocol 
Participants attended two separate laboratory visits at 08:30 am in the fasted state (Henson et al. 2016). 
They were asked to refrain from food and drink containing alcohol and caffeine for 24-h before and to 
avoid moderate-to-vigorous exercise 48-h before each condition to exclude possible acute influences on 
insulin sensitivity (Mikines et al. 1988). Participants were asked to weigh and record all food and 
beverages consumed for 24-h before their first experimental condition and then consume the same volume 
of food and beverage at the exact times in the 24-h before their second experimental condition. This was 
to minimise the influence of chronobiological aspects of dietary intake (e.g., timing, and frequency) and 
macronutrient intake on cardiometabolic risk marker responses (Ekmekcioglu and Touitou 2011). 
Participants were instructed to travel by car and park as close as possible to the laboratories to minimise 
physical activity in the hours before each condition. Upon arrival, participants sat for 5-min and resting 
BP and HR were measured. Afterwards, resting expired air was collected continuously for 5-min using a 
Metalyzer 3B (Cortex Biophysik, Leipzig, Germany). A fasting blood sample was then taken immediately 
before consuming a standardised breakfast. The 5-h experimental condition began immediately after the 
breakfast was consumed. The conditions were as follows, as illustrated in Fig. 1: 
 
(1) SIT: Participants remained seated at a desk for 5-h and were instructed to reduce excessive 
movement. 
 
(2) INT-SIT: Participants interrupted their sitting every 30-min with walking on a motorised treadmill 
at a light-intensity for 5-min. Participants started the walking breaks at 30, 60, 90, 120, 150 and 
180-min into the breakfast postprandial period and 30, 60 and 90-min into the lunch postprandial 
period. The walking breaks were undertaken on nine occasions, providing a total of 45-min of 
light walking. 
 
A standardised lunch meal was provided at 3 h into each condition. Participants were permitted to read 
books, newspapers, and magazines, or work on a laptop/computer throughout the conditions. When 
participants needed to use the toilet, they were transported in a wheelchair to avoid physical activity. 
 
 
 

3 
 
 
Statistical analysis plan 
 
Statistical analyses were performed using SPSS version 26.0 (SPSS Inc., NY, USA). Data were tested for normality 
using Q–Q plots prior to statistical analysis. Linear mixed models were used to determine the main effect of condition 
(INT-SIT vs. SIT) for the AUC variables and the condition × time (i.e. sample time points during each condition) 
interaction for all other outcomes. All models were adjusted for condition order and the baseline value of each 
outcome. Condition, time and covariates were included as fixed factors and participants were a random factor in each 
model. Two-tailed statistical significance was set at p ≤ 0.05. Cohen’s d effect sizes were calculated with 0.2, 0.5, and 
0.8 indicating a small, medium or large effect, respectively (Cohen 1988). All data are presented as mean (95% 
confidential interval [CI]) unless stated otherwise. 
 
 
 
 
 
 
 
 

4 
 
 
Participant information sheet 
 
School of Sport Science and Physical Activity 
Institute for Sport and Physical Activity Research (ISPAR) 
University of Bedfordshire 
Polhill Avenue, Bedford, MK41 9EA 
 
 
 
Participant Information Sheet 
 
 
Study title: Effects of breaking up prolonged sitting on postprandial cardiometabolic disease risk markers 
in normal weight versus overweight and obese South Asian adults. 
 
Principal 
Kamalesh Dey, University of Bedfordshire 
Investigators: 
Dr Daniel Bailey, University of Bedfordshire 
Project date: 
April 2019 – July 2020 
Email: kamalesh.dey@study.beds.ac.uk ; daniel.bailey@beds.ac.uk 
Telephone: 01234 793053/ 07574748607 
 
 
Study title 
Effects of breaking up prolonged sitting on postprandial cardiometabolic disease risk markers in 
normal weight versus overweight and obese South Asian adults. 
 
Invitation paragraph 
Dear Participant, 
 
You are being invited to take part in a research study. Before you decide it is important for you to 
understand why the research is being done and what it will involve. Please take time to read the 
following information carefully and discuss it with others if you wish. Ask us if there is anything that is 
not clear or if you would like more information. Take time to decide whether or not you wish to take 
part. Thank you for reading this. 
 
What is the purpose of the study? 
 
The purpose of this research project is to examine whether breaking up prolonged sitting with short 
regular bouts of walking can reduce blood sugar and cholesterol levels after eating, which are risk 
markers for Type 2 diabetes and heart disease. We want to test this in normal weight and 
overweight/obese South Asian adults as South Asians have a higher risk of these diseases. Breaking 
up sitting may help lower blood sugar and cholesterol levels but we need to test if this happens in 
South Asians. 
 
What type of participant is needed? 
This study requires participants who meet all of the following criteria: 
▪ 
18-65 years old 
▪ 
Male and female 
▪ 
Has not been diagnosed with diabetes or heart disease. 
▪ 
Does not smoke 
▪ 
Is not currently pregnant or given birth in the past 6 months. 
▪ 
No other issues identified in the health screen questionnaires that may be affected by study 
participation (e.g. pacemakers fitted, allergies to the test meals). 

5 
 
Do I have to take part? 
It is up to you to decide whether or not to take part. If you do decide to take part you will be 
given this information sheet to keep and be asked to sign a consent form. If you decide to take 
part you are still free to withdraw at any time and without giving a reason. A decision to withdraw 
at any time, or a decision not to take part, will not affect the standard of care you receive. 
 
What will happen to me if I take part? 
You will be invited to attend a preliminary testing session, where you can become familiar with 
walking at a light intensity on a treadmill and have your height, weight, and body fat measured. After 
completing this session, you will be invited to two main trials. Trials days will be at least 3 days apart 
and will start at approximately 9:00 am at the Sport and Exercise Science Laboratories at the 
University of Bedfordshire (Bedford Campus). 
 
In the 48 hours leading up to a main trial, you will be required to avoid exercise, and in the 24 hours 
beforehand also avoid alcohol and caffeine. You will also be asked to record the weight and timings 
of what you eat in a food diary for 24 hours before your first main trial, and replicate your recorded 
diet exactly before your second trial. You will be asked to fast overnight before you attend (except 
drinking water). In addition, women will be asked to complete both of their trials during their follicular 
phase of their menstrual cycle (this is 1-10 days after the start of menstruation/period). Trial days will 
last be 5 hours long but allow up to 6½ hours as we need to take measures from you before and after. 
Please bring laptops, books, magazines, newspapers, and DVDs to keep you busy during rest time. 
 
Upon arrival to the two main trial days, your resting blood pressure will be measured and a finger- prick 
blood sample will be taken. Afterwards, you will be provided with a breakfast meal. Following these 
procedures, the trial will begin: 
For trial 1: you will be asked to remain seated for the whole duration (5 hours). 
 
For trial 2: you will be asked to remain seated for the whole duration, but complete light 
intensity walking for 5 minutes every 30 minutes. 
 
During each main trial, blood pressure will be taken 11 times and blood samples will be taken 10 times. 
You will also be asked to wear a face mask for 5 minutes 11 times throughout the main trials, so we 
can measure how much carbohydrate and fat you are burning. 
 
Breakfast will consist of cornflakes, whole milk, white bread, orange juice, spreadable butter, and 
strawberry jam. Lunch will be provided consisting of a chicken or cheese sandwich, ready salted 
crisps, Lucozade drink, and milk chocolate bar. Let us know if you are unable to eat any of these foods 
and we will find some alternatives for you instead. In addition, Halal and vegetarian option will be 
available for participants in this study. 
 
What are the possible benefits of taking part? 
Everyone that takes part in the study will be provided with a summary of the study findings. In addition, 
participants will be provided their individual body mass index, blood sugar, and cholesterol) levels. 
 
What are the possible risks of taking part in the study? 
This research project involves sitting for 5 hours uninterrupted on one of the trial days. Although there 
will be no immediate risk to your health from this period of sitting, there will be the possibility it might 
cause feelings of discomfort, such as back pain. If this happens the trial will be stopped. 
 
The completion of a health screening questionnaire prior to participation is essential, as this will 
identify any potential issues with you being able to do walking. The walking will be completed on 
a motorised treadmill, which could cause injury if used incorrectly. To prevent this, you will have 
a practice session with the treadmill machine and you will need to wear appropriate footwear. 
 
You will have finger prick blood samples taken 10 times during each trial day. To minimise the risk of 
cross-infection, which is very rare, individuals with a known blood-borne disease will not be allowed 
to take part in the study and blood samples will be taken by a trained person following best 

6 
 
 
practice guidelines. During both of the main trial days, you will be provided with a breakfast and a 
lunch meal. If you are allergic to any of the foods being provided you will be excluded from the study 
or we will attempt to find suitable alternative foods for you to consume. 
 
What will happen to the data and information collected? 
All information and results collected will be kept strictly confidential and also held securely on a 
password-protected device or locked filing cabinets at the Sport and Exercise Science Laboratories, 
University of Bedfordshire and will only be accessible to University staff involved with the project. Any 
information about you will have your name and address removed so that you cannot be recognised 
from it. In addition, a unique ID code will be used for each participant in this study to maintain their 
confidentiality. 
 
What will happen to the results of the research study? 
Results of this research study may be published, but any data included will in no way be linked to any 
individual participant and you will not be identified in any publication. 
 
Contacts for further information? 
Questions are always welcome, and you are free to ask the research student (Kamalesh Dey), or the 
supervisory team (Dr Daniel Bailey), any questions at any time. See below for specific contact details. 
 
Many Thanks 
 
 
Contact Details 
 
Kamalesh Dey 
Email: kamalesh.dey@study.beds.ac.uk Phone: 01234 793053 
 
Dr Daniel Bailey 
Email: daniel.bailey@beds.ac.uk Phone: 01234 793237 
 
 
Alternatively, if you would like to speak with someone independent from the research study please 
contact: 
 
Dr Andrew Mitchell 
Head of School of Sport Science and Physical Activity 
 
Phone: 44 (0)1234 793363 
Email: andrew.mitchell@beds.ac.uk 
 
 
Thank you for taking your time to read this information letter. Please keep this form for your records. 
 
 

7 
 
Consent form for participants 
 
 
Study title: Effects of breaking up prolonged sitting on postprandial cardiometabolic disease risk 
markers in normal weight versus overweight and obese South Asian adults. 
 
Principal 
Kamalesh Dey, University of Bedfordshire 
Investigators: 
Dr Daniel Bailey, University of Bedfordshire 
Project date: 
April 2019 – July 2020 
Email: kamalesh.dey@study.beds.ac.uk ; daniel.bailey@beds.ac.uk 
Telephone: 01234 793053/ 07574748607 
 
To be completed by participant 
 
 
Name of the participant: ………………………………………………………… 
 
I have read the information sheet concerning this project and understand what is about. All my further 
questions have been answered to my satisfaction. I understand that I am free to request further 
information at any stage. 
I know that: 
❖ My participation in the project is entirely voluntary and I am free to withdraw from the 
project at any time without disadvantage or prejudice. 
❖ I will be required to attend three sessions to complete the project. 
❖ As part of the study I will have to: 
➢ Sit for 5 hours on two occasions (on separate days), once prolonged sitting 
and once with walking breaks where I will complete light intensity walking 
for 5 minutes every 30 minutes; 
➢ Have finger-prick blood samples taken a total of 10 times, expired air 
sample taken 11 times, and blood pressure taken 11 times during each 
main trial day; 
➢ Consume one breakfast and lunch meal for each of the main per trial days. 
❖ I am aware of any risks that might be involved with the project. 
❖ All information and data collected will be published but anonymity will be preserved. 
 
 
Signed: ……………………………………… (Participant) Date: …………………………………….. 
 
 
Thank you for your participation! Please complete and return this form to the research staff. 
 
 
 

8 
 
Ethical approval confirmation: