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ObesityNCT04887454

Optimal Frequency of High-Intensity Interval Training for Centrally Obese Adults

A study testing Once-Weekly HIIT and Thrice-Weekly HIIT in people with Obesity, run by The University of Hong Kong at 1 site in Hong Kong.

Completed

Finished. The study has ended and is not enrolling. Results may be posted on the official record.

Official record
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Trial summary

The aim of this study is to examine the therapeutic effectiveness of two different exercise frequencies of high-intensity interval training (HIIT; once versus thrice weekly, with matched weekly exercise volume) on improving cardiometabolic risk factors in centrally obese adults. Read more about this study

Who is it for?
Ages 18 years and older
Conditions the study is for
Obesity
What is being tested?
Once-Weekly HIIT and Thrice-Weekly HIIT
Could I receive a placebo?
No, everyone receives an active treatment
How many people
315 participants
Where
1 siteHong Kong
Study dates
1 Sep 2021to 7 Sep 2024
Phase
Interventional
Are there results?
None posted in the registry

Key requirements

Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.

  • Ages 18 years and older
  • All sexes
  • No healthy volunteers
  • Adult, Older adult

Who may be able to join

  • Aged above 18 years
  • Ethnic Chinese
  • Overweight (BMI ≥23 for Asian)
  • Centrally obese according to IDF and NCEP with Asian-specific cut-off (waist circumference ≥90 cm for males; ≥80 cm for females)
  • Males and females

Who cannot join

  • Medical and somatic conditions that prevent brisk walking
  • Chronic diseases affecting mobility and motor function (e.g., neurological disease, musculoskeletal disorder, spinal cord injury, autoimmune, arthritis, Parkinson's Disease)
  • Chronic diseases affecting cardiorespiratory and metabolic health (e.g., cancers, cardio-/cerebrovascular diseases, heart disease, diabetes mellitus, pneumonia, chronic pulmonary diseases, nephritis, nephrosis)
  • Signs of cardiac arrhythmia indicated by aberrant electrocardiography during incremental VO2max test
  • Regular moderate-to-vigorous intensity exercise (≥150 min weekly) in the past 3 months, as screened by a specially designed questionnaire
  • Daily smoking habit
Show all 9Show fewer
  • Excess alcohol consumption (daily ≥30g for men, ≥20g for women) in the past six months
  • Claustrophobia
  • Surgery, therapy or medication for obesity or weight loss in the past six months (e.g., gastric bypass, gastric band, sleeve gastrectomy, gastric reduction duodenal switch, and dietitian-prescribed dietary program)

Trial locations and contacts

1 site in 1 country.

Hong Kong1 site

  • LKS Faculty of Medicine

    Hong Kong

Other trials in Hong Kong

About this study

The aim of this study is to examine the therapeutic effectiveness of two different exercise frequencies of high-intensity interval training (HIIT; once versus thrice weekly, with matched weekly exercise volume) on improving cardiometabolic risk factors in centrally obese adults.

Read the detailed description

HIIT is an emerging, popular, promising, cost-effective, and time-efficient exercise modality for managing obesity. Although lower-frequency HIIT is favorable for intervention adherence, the optimal exercise frequency of HIIT for alleviating obesity is unknown.

This study is a three-arm randomized controlled trial. Centrally obese adults will be randomly allocated to three groups: the usual care control, once and thrice-weekly HIIT groups. Led by research personnel, the usual care group will receive obesity-related health education. Led by athletic coaches, the HIIT intervention groups will receive 16 weeks of once or thrice weekly HIIT (with matched weekly exercise volume). Outcome measures of this study will be examined at baseline, 4 months (post-intervention), and 8 months (follow-up), by assessors blinded to group allocation.

Conditions
Obesity
Being tested
Once-Weekly HIIT, Thrice-Weekly HIIT, Usual Care
Keywords
Obesity, Central Obesity, High-Intensity Interval Training, Aerobic Exercise, Adults, Metabolic Syndrome
Medical subject headings
Obesity, Obesity, Abdominal, Metabolic Syndrome

What participants receive

What participants receive. In a randomised study each person is assigned to one group by chance.

  • Once-Weekly HIITBehavioural

    Participants in this group will receive a 16-week intervention of HIIT once weekly supervised by certified athletic coaches. Participants will perform four 4-minute intervals at 85%-95% peak heart rate with a 3-minute active recovery between each 4-minute interval. Participants will repeat the 25-minute HIIT bout three times with 30-60 minutes break in between each 25-minute HIIT bout. Health information provided to the usual care control group will be made available to the participants in the HIIT groups.

  • Thrice-Weekly HIITBehavioural

    Participants in this group will receive a 16-week intervention of HIIT thrice weekly supervised by certified athletic coaches. Participants will perform four 4-minute intervals at 85%-95% peak heart rate with a 3-minute active recovery between each 4-minute interval. Health information provided to the usual care control group will be made available to the participants in the HIIT groups.

  • Usual CareOther

    Participants in the usual care control group will receive health education delivered by research personnel. This program will consist of eight two-hour bi-weekly sessions covering major health issues relating to obesity including causes, prevalence, epidemiology, associated diseases, healthy diet, caloric restriction advice, physical activity, stress management, adequate sleep, as well as lifestyle counseling/consultation and goal-setting/record-keeping strategies for behavioral changes.

Study groups in NCT04887454
Study groupRoleWhat they receive
Once-Weekly HIITExperimentalOnce-weekly HIIT for 16 weeks, led by certified athletic coaches
Receives: Behavioral: Once-Weekly HIIT
Thrice-Weekly HIITExperimentalThrice-weekly HIIT for 16 weeks, led by certified athletic coaches
Receives: Behavioral: Thrice-Weekly HIIT
Usual CareOtherBi-weekly health education, led by research personnel
Receives: Other: Usual Care

What is being measured

The primary outcome is the main question the study is designed to answer.

  1. Change in Body Fat

    Total body fat mass will be assessed using dual-energy X-ray absorptiometry (DXA)

    Measured: Baseline and 4 months

Secondary outcomes (21)

  1. Change in Body Fat

    Total body fat mass will be assessed using dual-energy X-ray absorptiometry (DXA)

    Measured: Baseline and 8 months

  2. Change in Abdominal Visceral Fat

    Abdominal visceral fat will be assessed using magnetic resonance imaging (MRI)

    Measured: Baseline and 4 and 8 months

  3. Change in Abdominal Subcutaneous Fat

    Abdominal subcutaneous fat will be assessed using magnetic resonance imaging (MRI)

    Measured: Baseline and 4 and 8 months

  4. Change in Body Mass Index

    Weight and height will be assessed using a calibrated electronic digital weighing scale and stadiometer respectively

    Measured: Baseline and 4 and 8 months

  5. Change in Waist Circumference

    Waist circumference will be assessed using an inelastic measuring tape to the nearest 0.1cm on bare skin

    Measured: Baseline and 4 and 8 months

  6. Change in Systolic Blood Pressure

    Resting systolic blood pressure will be assessed

    Measured: Baseline and 4 and 8 months

  7. Change in Diastolic Blood Pressure

    Resting diastolic blood pressure will be assessed

    Measured: Baseline and 4 and 8 months

  8. Change in Fasting Glucose

    Fasting glucose will be analyzed from venous blood by an accredited medical laboratory

    Measured: Baseline and 4 and 8 months

  9. Change in Fasting Triglycerides

    Fasting triglycerides will be analyzed from venous blood by an accredited medical laboratory

    Measured: Baseline and 4 and 8 months

  10. Change in Fasting Low Density Lipoprotein Cholesterol (LDL-C)

    Fasting LDL-C will be analyzed from venous blood by an accredited medical laboratory

    Measured: Baseline and 4 and 8 months

  11. Change in Fasting High Density Lipoprotein Cholesterol (HDL-C)

    Fasting HDL-C will be analyzed from venous blood by an accredited medical laboratory

    Measured: Baseline and 4 and 8 months

  12. Change in Fasting Total Cholesterol

    Fasting total cholesterol will be analyzed from venous blood by an accredited medical laboratory

    Measured: Baseline and 4 and 8 months

  13. Change in Proportion of Metabolic Syndrome Diagnosis

    Metabolic syndrome diagnosis will be evaluated with waist circumference, triglycerides, HDL-C, blood pressure, and fasting glucose

    Measured: Baseline and 4 and 8 months

  14. Number of Adverse Events

    Adverse events related or unrelated to training will be assessed

    Measured: Baseline and 4 and 8 months

  15. Change in Organ Fat

    Organ fat will be assessed using magnetic resonance imaging (MRI)

    Measured: Baseline and 4 and 8 months

  16. Change in SF-12 Physical Component Summary Score

    Physical health-related quality of life will be assessed using the Physical Component Summary Score of the 12-Item Short-Form Health Survey (SF-12)

    Measured: Baseline and 4 and 8 months

  17. Change in SF-12 Mental Component Summary Score

    Mental health-related quality of life will be assessed using the Mental Component Summary Score of the 12-Item Short-Form Health Survey (SF-12)

    Measured: Baseline and 4 and 8 months

  18. Change in HADS-D Score

    HADS-D score will be assessed using the Depression subscale of the Hospital Anxiety and Depression Scale (HADS-D)

    Measured: Baseline and 4 and 8 months

  19. Change in PHQ-9 Score

    PHQ-9 score will be assessed using the Patient Health Questionnaire-9 (PHQ-9)

    Measured: Baseline and 4 and 8 months

  20. Change in HADS-A Score

    HADS-A score will be assessed using the Anxiety subscale of the Hospital Anxiety and Depression Scale (HADS-A)

    Measured: Baseline and 4 and 8 months

  21. Change in GAD-7 Score

    GAD-7 score will be assessed using the General Anxiety Disorder-7 (GAD-7) Questionnaire

    Measured: Baseline and 4 and 8 months

Timeline

From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.

  1. First posted14 May 2021
  2. Study start1 Sep 2021
  3. Primary completion7 Sep 2024
  4. Study completion7 Sep 2024

Resources

More details

For doctors and researchers: how the study is designed, who runs it, and its registry IDs.

Study design
Study type
Interventional
Phase
Phase N/A
Primary purpose
Treatment
Allocation
Randomised
Intervention model
Parallel groups
Masking
Single blind
Who is masked
Outcomes assessor
Enrolment
315 participants (actual)
IDs, dates and publications
ClinicalTrials.gov ID
NCT04887454
Sponsor's protocol ID
1v3HIIT
Status last verified
Mar 2025
First submitted
10 May 2021
Last updated
30 Mar 2025
Results posted
No
FDA-regulated drug
No
FDA-regulated device
No
Individual data sharing
Yes: The data of individual participants that underlie the results reported in this trial, after de-identification including text, tables, figures, and appendices, as well as study protocol and statistical analysis plan, will be shared after 3 months of study publication. Data will be shared with researchers who provide a methodologically sound proposal for academic purposes. Proposals should be directed to pmsiu@hku.hk to gain access and for data request, a data-access agreement needs to be signed.

Publications

  • Siu PM, Leung CK, Bernal JDK, Yu AP, Recchia F, Tam BT, Fong DYT, Chan DKC, Ngai HH, Lee CH, Yung PSH, Wong SHS, Gibala M. Once and thrice weekly interval training in adults with central obesity: a randomized controlled trial. Nat Commun. 2026 Jan 10;17(1):1410. doi: 10.1038/s41467-025-68149-7.

    PubMed 41519797

  • Leung CK, Bernal JDK, Yu AP, Recchia F, Tam BT, Fong DYT, Chan DKC, Ngai HH, Lee CH, Yung PSH, Wong SHS, Gibala M, Siu PM. Effects of volume-matched once-weekly and thrice-weekly high-intensity interval training (HIIT) on body adiposity in adults with central obesity: Study protocol for a randomized controlled trial. J Exerc Sci Fit. 2024 Oct;22(4):329-340. doi: 10.1016/j.jesf.2024.05.001. Epub 2024 Jun 14.

    PubMed 38993983

Questions about this trial

What is this clinical trial studying?

A study testing Once-Weekly HIIT and Thrice-Weekly HIIT in people with Obesity, run by The University of Hong Kong at 1 site in Hong Kong.

The full registered description is in the About this study section and the official record.

Who may be eligible to take part?

The sponsor lists 5 inclusion and 9 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.

Is this clinical trial currently recruiting?

The record says: finished, as of the sponsor's last update on 30 Mar 2025. Status can change between updates, so confirm with the study contact before making plans.

Where is the study taking place?

The record lists 1 site in Hong Kong. Whether a site is taking part right now should be confirmed with that site. See every site.

What are the possible benefits and risks?

They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.

Are results available for this study?

The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.

How can a doctor refer a patient or contact the research team?

The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.

What does the primary outcome measure?

Change in Body Fat (time frame: Baseline and 4 months). It is what the study was designed to measure, not a finding.

Where can I read the original study information?

On the ClinicalTrials.gov record for NCT04887454, which also lists 2 linked publications.

Does a listing mean the treatment is approved or proven to work?

No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.

How often is this information updated?

AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 30 Mar 2025; AzTrials last refreshed its copy on 6 Nov 2026.

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