Clinical trial NCT04545320: Effectiveness of High-intensity Interval Training (HIIT) Versus Moderate-intensity Continuous Training (MICT) in Reducing Visceral Fat in Adults With Central Obesity
Official title: Effectiveness of Once-a-week High-intensity Interval Training (HIIT) Versus Moderate-intensity Continuous Training (MICT) in Reducing Visceral Fat in Adults With Central Obesity, a Pilot Randomized Controlled Trial.
Study type: INTERVENTIONAL
Overall status: WITHDRAWN
Phase: NA
Conditions: Central Obesity
Keywords: Central Obesity
Visceral Fat
HIIT
MICT
Lead sponsor: The University of Hong Kong
Sponsor class: OTHER
First posted: 2020-09-11
Enrollment: 0
Sex: ALL
Minimum age (years): 18
Maximum age (years): 60
Standard ages: ADULT
Accepts healthy volunteers: no
Allocation: RANDOMIZED
Intervention model: PARALLEL
Primary purpose: TREATMENT

Brief summary: Obesity is a major risk factor for cardiovascular disease and diabetes as well as all-cause mortality. The prevalence of obesity has continuously increased in most countries and has doubled in over 70 countries since 1980. The World Health Organization (WHO) estimated in 2014 that \~600 million (13%) adults were obese and \~1.9 billion (39%) were overweight worldwide. Notably, United States and China have the highest numbers of obese adults. According to a national survey in China in 2014 conducted among 146,703 Chinese adults aged 20-59, the prevalence of obesity was 13%, central obesity was 25% and overweight was 41%. In Hong Kong, the Behavioural Risk Factor Survey conducted by the Government in 2016 found 39% of adults were classified as overweight or obese, of which 21% were obese. The prevalence of central obesity has also risen steadily since 1999 in America. By 2030 is projected to reach 55.6% in men, 80.0% in women, 47.6% among girls and 38.9% among boys in the United States. Overweight, obesity and central obesity are now already pandemic public health issues causing heavy burden on healthcare system. Nowadays, lifestyle modification interventions still remain as the primary strategy to manage obesity and obesity-related complications, among which exercise is low-cost and effective. Substantial evidences have demonstrated effectiveness of HIIT and MICT in reducing body adiposity and improving body Anthropometry. However, studies have also pointed out "lack of time" is one of the major barriers preventing patients from exercise participation. Therefore, studies have put focus on low-frequency or low-volume exercise in improving health to reduce time commitment and increase exercise adherence. Among substantial evidence, our recent study demonstrated once-a-week HIIT is effectively in improving body composition. The effectiveness of low-frequency exercise in reducing visceral fat has also been explored. However, a recent meta-analysis showed low-frequency exercise is not effective in reducing visceral fat. Notably, the authors pointed out most of studies included in the meta-analysis adopted cycling exercise modality and they suggested walking or running exercise which recruits more body muscles may exert better results. In this study, we propose to adopt walking exercise modality to fill the research gap identified by the meta-analysis. Also, no study has compared the effectiveness of low-frequency HIIT and MICT in reducing visceral fat determined by magnetic resonance imaging (MRI) previously.

Study aim: to examine the effectiveness of once-a-week high-intensity interval training (HIIT) versus moderate-intensity continuous training (MICT) in reducing visceral fat in adults with central obesity


Eligibility criteria: Inclusion Criteria:

1. Adults aged 18 - 60,
2. Central obesity, defined as BMI ≥25 (obesity classification adopted by the Hong Kong Government) with waist circumference of ≥90 cm for men and ≥80 cm for women (abdominal obesity according to the International Diabetes Federation's Chinese ethnic-specific criterion),
3. Males and females will be included to enhance generalizability.

Exclusion Criteria:

1. ≥150 minutes moderate-intensity or ≥75 minutes vigorous-intensity exercise weekly,
2. Regular HIIT or MICT (≥1 weekly) in the past 6 months,
3. Medical history of cardiovascular disease, chronic pulmonary or kidney disease, heart failure, cancer, etc.,
4. Somatic conditions that limit exercise participation (e.g., limb loss),
5. Impaired mobility due to chronic diseases (e.g., chronic arthritis/osteoarthritis, neurological, musculoskeletal and autoimmune diseases),
6. Daily smoking and drinking habit,
7. Surgery, therapy or medication for obesity or weight loss in the past 6 months (e.g., gastric bypass, gastric band, sleeve gastrectomy, gastric reduction duodenal switch, and dietitian-prescribed dietary program).

Primary outcomes:
measure: Visceral fat
timeFrame: 3-month follow-up
Secondary outcomes:
measure: Subcutaneous fat
timeFrame: 3-month follow-up
measure: Body fat mass
timeFrame: 3-month follow-up
measure: Body fat percentage
timeFrame: 3-month follow-up
measure: Body Mass Index
timeFrame: 3-month follow-up
measure: Waist Circumference 1
timeFrame: 3-month follow-up
measure: Waist Circumference 2
timeFrame: 3-month follow-up
measure: Cardiorespiratory fitness
timeFrame: 3-month follow-up
measure: Bone Mineral Density
timeFrame: 3-month follow-up
measure: Lean Mass
timeFrame: 3-month follow-up
measure: Health-related Quality of Life
timeFrame: 3-month follow-up
measure: Adherence
timeFrame: 3-month follow-up
measure: Adverse Events
timeFrame: 3-month follow-up
measure: Medication
timeFrame: 3-month follow-up
measure: Habitual Physical Activity
timeFrame: 3-month follow-up
measure: Dietary Intake
timeFrame: 3-month follow-up
measure: Blood pressure
timeFrame: 3-month follow-up
measure: Hip circumference
timeFrame: 3-month follow-up
measure: Self-report habitual physical activity
timeFrame: 3-month follow-up
measure: Enjoyment
timeFrame: 3-month follow-up
Other outcomes:
Locations:
city: Hong Kong
country: Hong Kong
facility: Li Ka Shing Faculty of Medicine, The University of Hong Kong
Study officials:
affiliation: Li Ka Shing Faculty of Medicine, The University of Hong Kong
name: Ming Fai Parco Siu, PhD
role: PRINCIPAL_INVESTIGATOR
References: