Effects of interrupting sitting on glycemic control

ISRCTN	ISRCTN15716578
DOI	https://doi.org/10.1186/ISRCTN15716578
ClinicalTrials.gov (NCT)	Nil known
Clinical Trials Information System (CTIS)	Nil known
Protocol serial number	Nil known
Sponsor	Zhejiang University
Funder	National Natural Science Foundation of China

Submission date: 04/07/2023
Registration date: 05/07/2023
Last edited: 14/07/2025

Recruitment status: No longer recruiting
Overall study status: Completed
Condition category: Nutritional, Metabolic, Endocrine

Prospectively registered

Protocol

Statistical analysis plan

Results

Individual participant data

Plain English summary of protocol

Background and study aims
The sedentary (inactive) lifestyle, which is highly associated with heart disease and type 2 diabetes, has become highly prevalent in the last decade. Breaking up prolonged sitting time with physical activities has been proven to be beneficial for postprandial (after meals) glucose response. The specific pattern (intensity, frequency, and modality) still remains to be determined. The aim of this study is to examine the effects of breaking up sitting time with brief bouts or a single bout of activities, all having a unique muscle activity pattern but similar energy expenditure, on postprandial glucose responses in overweight and obese men.

Who can participate:
Healthy Chinese young adults between 18-25 years old with body mass index (BMI) over 24 kg/m2

What does the study involve?
Participants are randomly allocated to prolonged sitting for 8.5 hours, sitting with 30-min walking, sitting with 3-min walking every 45 min, or sitting with 3-min squatting every 45 min. Participants undergo glucose and leg muscle activity measurements.

What are the possible benefits and risks of participating?
The benefits are that participants can understand their glucose metabolism and were given an individualized sedentary break program. The risks are participants may be afraid to wear a continuous glucose monitor.

Where is the study run from?
Zhejiang University (China)

When is the study starting and how long is it expected to run for?
April 2020 to August 2021

Who is funding the study?
National Natural Science Foundation of China

Who is the main contact?
Dr Ying Gao, yigao@zju.edu.cn

Contact information

Dr Ying Gao
Scientific

Number 866
Yuhangtang Road
Xihu District
Hangzhou
310058
China

Phone	+86 (0)15967119137
Email	yigao@zju.edu.cn

Study information

Primary study design	Interventional
Study design	Randomized four-arm crossover study
Secondary study design	Randomised cross over trial
Study type	Participant information sheet
Scientific title	Muscle activity when interrupting prolonged sitting improves glycemic control in overweight and obese men
Study objectives	Breaking up prolonged sitting time with physical activities would attenuate postprandial glucose response. Multiple breaks would elicit more pronounced glucose reduction through greater muscle activity.
Ethics approval(s)	Approved 02/06/2020, Medical Ethics Committee of Zhejiang University (866 Yuhangtang Rd, Hangzhou, 310058, China; +86 (0)15967119137; medicalethics@zju.edu.cn), ref: No.2020−099
Health condition(s) or problem(s) studied	Prevention of pre-diabetes in overweight and obese adults
Intervention	The randomization sequence was generated with an online statistical package (https://www.randomization.com). Participants were blinded to the order of the conditions until the commencement of each condition. SIT. Participants sat upright in a comfortable chair throughout the 8.5-h measurement and were instructed to minimize excessive movement. ONE. The protocol was identical to SIT, but participants performed a 30-min light-intensity walking on a treadmill at 4 km·h-1 with no gradient at 1:00 of the experiment time. The first bout commenced at 1:00 of the experiment time. WALK. The protocol was identical to SIT, but participants performed 3-min bouts of light-intensity walking on a treadmill at the same speed and gradient as ONE every 45 min, 10 times throughout the day, which accumulated a total of 30 min walking. The first bout commenced at 1:00 of the experiment time. SQUAT. The protocol was identical to SIT, but participants performed 3-min bouts of squatting following a soundtrack every 45 min, 10 times throughout the day, which accumulated a total of 30 min activity. The soundtrack would beep every 5 seconds.
Intervention type	Behavioural
Primary outcome measure(s)	Postprandial glucose measured using a continuous glucose monitor (CGM) throughout the 8.5-h intervention
Key secondary outcome measure(s)	1. Muscle activity measured using textile EMG shorts throughout the 8.5-h intervention 2. Heart rate measured using a heart rate belt throughout the 8.5-h intervention 3. Physical activity measured using accelerometry 2 days before each condition 4. Food intake measured using self-reported dialogue 2 days before each condition 5. Blood pressure measured using an electronic blood pressure monitor every 45 minutes during the measurement (beginning, 1:00, 1:45, 2:30, 3:15, 4:00, 4:45, 5:30, 6:15, 7:00, 7:45, and 8:30 of the experiment time) 6. Perceived feelings, including shoulder, upper limbs, waist, hip, and lower limbs discomfort, fatigue, and working efficiency, measured using a visual analogue scale every 45 minutes during the measurement (beginning, 1:00, 1:45, 2:30, 3:15, 4:00, 4:45, 5:30, 6:15, 7:00, 7:45, and 8:30 of the experiment time) 7. Energy expenditure of daily physical activity tasks, including supine, sitting, standing, walking, running, and squatting, measured using K5 indirect calorimetry 1 week before the intervention 8. Body composition, including body mass, fat mass, muscle mass, and liver fat index, measured using a bioelectrical impedance device 1 week before the intervention 9. Leg swelling measured using a self-made water tank (water displacement method) before and after each condition
Completion date	30/08/2021

Eligibility

Participant type(s)	Healthy volunteer
Age group	Adult
Lower age limit	18 Years
Upper age limit	35 Years
Sex	Male
Target sample size at registration	18
Key inclusion criteria	1. Healthy Chinese men aged 18-35 years old 2. Overweight or obese (BMI ≥24 kg/m2) 3. Sedentary (self-reported sitting time >6 h per day for last 2 months), physically inactive (not meeting the physical activity guideline of ≥150 min per week of moderate-intensity or ≥75 min per week of vigorous-intensity exercise for last 2 months) 4. Free of diabetes and cardiovascular diseases (fasting glucose ≤6.1 mmol/l) and nonsmoker
Key exclusion criteria	1. Self-reported chronic, long-term musculoskeletal disease 2. Cardiovascular or metabolic disease requiring medication known to affect metabolism 3. Change of body weight >2 kg in the past 2 months
Date of first enrolment	01/11/2020
Date of final enrolment	30/08/2021

Locations

Countries of recruitment

China

Study participating centre

Zhejiang University

Number 866
Yuhangtang Road
Xihu District
Hangzhou
310058
China

Results and Publications

Individual participant data (IPD) Intention to share	Yes
IPD sharing plan summary	Published as a supplement to the results publication
IPD sharing plan	The datasets generated and/or analysed during the current study will be published as a supplement to the results publication

Study outputs

Output type	Details	Date created	Date added	Peer reviewed?	Patient-facing?
Results article		12/07/2025	14/07/2025	Yes	No
Participant information sheet	Participant information sheet	11/11/2025	11/11/2025	No	Yes

Editorial Notes

14/07/2025: Publication reference added.
04/07/2023: Study's existence confirmed by the Medical Ethics Committee of Zhejiang University.