Effectiveness of High-intensity Interval Training (HIIT) Versus Moderate-intensity Continuous Training (MICT) in Reducing Visceral Fat in Adults With Central Obesity

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

Conditions

• Central Obesity

Interventions

BEHAVIORAL

Usual care control group

Health education

BEHAVIORAL

HIIT group

Once-a-week HIIT

BEHAVIORAL

MICT group

Once-a-week MICT

Sponsors & Collaborators

• The University of Hong Kong

  lead OTHER

Principal Investigators

• Ming Fai Parco Siu, PhD · Li Ka Shing Faculty of Medicine, The University of Hong Kong

Study Design

Allocation

RANDOMIZED

Purpose

TREATMENT

Masking

SINGLE

Model

PARALLEL

Eligibility

Min Age

18 Years

Max Age

60 Years

Sex

ALL

Healthy Volunteers

No

Timeline & Regulatory

Start

2020-09-01

Primary Completion

2022-10-31

Completion

2022-10-31

Countries

• Hong Kong

Study Locations