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.
试验速览
- 阶段
- 不适用
- 状态
- 撤回
- 试验地点
- 1
- 主要终点
- Visceral fat
研究概览
简要总结
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
研究设计
- 研究类型
- Interventional
- 分配方式
- Randomized
- 干预模型
- Parallel
- 主要目的
- Treatment
- 盲法
- Single (Outcomes Assessor)
盲法说明
The outcome assessor will be blinded from the group allocation and the participants will be instructed not to reveal his/her intervention assignment.
入排标准
- 年龄范围
- 18 Years 至 60 Years（Adult）
- 性别
- All
- 接受健康志愿者
- 否
入选标准
- •Adults aged 18 - 60,
- •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),
- •Males and females will be included to enhance generalizability.
排除标准
- •≥150 minutes moderate-intensity or ≥75 minutes vigorous-intensity exercise weekly,
- •Regular HIIT or MICT (≥1 weekly) in the past 6 months,
- •Medical history of cardiovascular disease, chronic pulmonary or kidney disease, heart failure, cancer, etc.,
- •Somatic conditions that limit exercise participation (e.g., limb loss),
- •Impaired mobility due to chronic diseases (e.g., chronic arthritis/osteoarthritis, neurological, musculoskeletal and autoimmune diseases),
- •Daily smoking and drinking habit,
- •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).
结局指标
主要结局
Visceral fat
时间窗: 3-month follow-up
The amounts of visceral fat (VAT) at the abdominal region will be assessed by a 1.5-Teala whole-body scanner. A breath-hold localizer scan will be performed prior to the MRI scan. T1-weighted in-phase images will be obtained by fast spoiled gradient-echo sequences during suspended end-expiration. The VAT and between the thoracic diaphragm and the upper broader of the first sacral vertebra will be manually marked on each transverse image to calculate the volume of abdominal VAT.
次要结局
- Subcutaneous fat(3-month follow-up)
- Hip circumference(3-month follow-up)
- Self-report habitual physical activity(3-month follow-up)
- Enjoyment(3-month follow-up)
- Bone Mineral Density(3-month follow-up)
- Health-related Quality of Life(3-month follow-up)
- Blood pressure(3-month follow-up)
- Body fat mass(3-month follow-up)
- Cardiorespiratory fitness(3-month follow-up)
- Waist Circumference 1(3-month follow-up)
- Adherence(3-month follow-up)
- Body fat percentage(3-month follow-up)
- Body Mass Index(3-month follow-up)
- Waist Circumference 2(3-month follow-up)
- Lean Mass(3-month follow-up)
- Adverse Events(3-month follow-up)
- Medication(3-month follow-up)
- Habitual Physical Activity(3-month follow-up)
- Dietary Intake(3-month follow-up)
研究者
Parco M. Siu, PhD
Associate Professor & Division Head
The University of Hong Kong