Low-frequency High-Intensity Interval Training in Overweight or Obese Young Adults

The Effectiveness of Low-frequency High-Intensity Interval Training (HIIT) in Overweight or Obese Young Adults

Background: The relationship between the frequency of high-intensity interval training (HIIT) and the resultant adaptations is largely unclear. Purpose: This study examined the effects of different frequencies of HIIT compared to moderate-intensity continuous training (MICT) on body composition and cardiovascular biomarkers in overweight or obese adults. Methods: This study was a randomized, controlled, single-blinded trial. Fifty-six overweight or obese men aged between 18 and 30 years were randomly assigned to no-intervention control (CON; n=14), MICT performed thrice weekly (MICT×3/wk; n=9), HIIT performed thrice weekly (HIIT×3/wk; n=14), HIIT performed twice weekly (HIIT×2/wk; n=10), and HIIT performed once weekly (HIIT×1/wk; n=9). Each HIIT session consisted of 12 × 1-min bouts at 90% heart rate reserve (HRR), interspersed with 11 × 1-min bouts at 70% HRR (HIIT×3/wk: 69 min/wk; HIIT×2/wk: 46 min/wk; HIIT×1/wk: 23 min/wk). Aerobic capacity, resting heart rate, body composition, waist circumference, blood pressure, endothelial function, fasting blood glucose and lipids, circulatory adipokines and inflammatory biomarkers were examined at baseline, after 4 weeks and 8 weeks of intervention.

Study Overview

• Status: Completed
• Conditions: Overweight and Obesity
• Intervention / Treatment: Behavioral: Exercise intervention

Detailed Description

Individuals who fulfilled the following inclusion criteria were invited to participate in the present study: 1) Chinese male; 2) aged 18-30 years; and 3) overweight or obesity, defined as BMI ≥23 kg/m2 (classification of overweight for Hong Kong adults according to Department of Health, Hong Kong SAR Government) (13). Subjects were excluded if they had: 1) chronic medical and health condition such as cardiovascular diseases, diabetes, neurological disease, musculoskeletal disorder, cancers, and autoimmune diseases; 2) hypertension (blood pressure >140/90 mmHg); 3) contraindications to participating in physical exercise; 4) any pre-existing medical or physical issues that affected the experimental test; 5) physically active (i.e., >3 hours of moderate-intensity exercise weekly) or 6) lean overweight population (BMI ≥23 kg/m2, but percent body fat ≤20%) according to the BMI data corresponding to bioelectrical impedance estimated percent body fat cut-off value among Hong Kong Chinese adults.

Of those who were screened, 103 Chinese young adults were eligible to participate in this study. They were provided with written and verbal information on the study protocol and the possible associated discomforts and risks followed by obtaining their written informed consent to participate in this study. The study protocol and consent form were approved by the Human Subjects Ethics Sub-Committee of The Hong Kong Polytechnic University (ethics approval reference number: HSEARS20160927005-01).

This study was a single-blind, randomized, controlled trial. Subjects were randomly assigned to 1) no-intervention control (CON), 2) MICT performed thrice weekly (MICTx3/wk), 3) HIIT performed thrice weekly (HIITx3/wk), 4) twice weekly (HIITx2/wk), and 5) once weekly (HIITx1/wk). All subjects were instructed to maintain their usual daily activities. Outcome measures including aerobic capacity, body composition, blood pressure, resting heart rate, endothelial function, arterial stiffness, fasting glucose, lipids markers, adipokine marker, and inflammatory marker were assessed at baseline, 4 weeks and 8 weeks after the intervention.

• Study Type: Interventional
• Enrollment (Actual): 103
• Phase: Not Applicable

Contacts and Locations

Study Locations

• Hong Kong
  • Hong Kong, Hong Kong
    • LKS Faculty of Medicine

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 18 years to 30 years (Adult)
• Accepts Healthy Volunteers: No
• Genders Eligible for Study: Male

Description

Inclusion Criteria:

1. Chinese male
2. Aged 18-30 years
3. Overweight or obesity, defined as BMI ≥23 kg/m2 (classification of overweight for Hong Kong adults according to Department of Health, Hong Kong SAR Government)

Exclusion Criteria:

1. Chronic medical and health condition such as cardiovascular diseases, diabetes, neurological disease, musculoskeletal disorder, cancers, and autoimmune diseases
2. Hypertension (blood pressure >140/90 mmHg)
3. Contraindications to participating in physical exercise
4. Any pre-existing medical or physical issues that affected the experimental test
5. Physically active (i.e., >3 hours of moderate-intensity exercise weekly)
6. Lean overweight population (BMI ≥23 kg/m2, but percent body fat ≤20%) according to the BMI data corresponding to bioelectrical impedance estimated percent body fat cut-off value among Hong Kong Chinese adults.

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: Single

Number of Arms

5

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
No Intervention: Control; Subjects in this group do not received any intervention
Active Comparator: Moderate Intensity Continuous Training ×3/wk; Subjects in this group will receive three sessions of Moderate-Intensity Continuous Training per week throughout the 8 weeks experimental period	Behavioral: Exercise intervention; HIIT groups performed 30-meter shuttle runs on a rooftop covered field whereas MICT group ran on a footpath with an overall flat and non-slippery road surface. All training sessions were preceded by a 5-minute self-pace warm-up jogging and ended with a 5-minute self-pace jogging or walking cool-down. Each session of MICT consisted of 30 minutes of continuous exercise at an intensity of 60% of heart rate reserve (HRR); [i.e., (maximal HR - resting HR) × intensity + resting HR]. For each HIIT session, the intensity was set at 90% HRR for high-intensity bouts, interspersed with active recovery at 70% HRR. All exercise sessions were supervised by qualified athletic coach or strength and conditioning coach.
Active Comparator: High Intensity Interval Training×3/wk; Subjects in this group will receive three sessions of High-Intensity Interval Training per week throughout the 8 weeks experimental period	Behavioral: Exercise intervention; HIIT groups performed 30-meter shuttle runs on a rooftop covered field whereas MICT group ran on a footpath with an overall flat and non-slippery road surface. All training sessions were preceded by a 5-minute self-pace warm-up jogging and ended with a 5-minute self-pace jogging or walking cool-down. Each session of MICT consisted of 30 minutes of continuous exercise at an intensity of 60% of heart rate reserve (HRR); [i.e., (maximal HR - resting HR) × intensity + resting HR]. For each HIIT session, the intensity was set at 90% HRR for high-intensity bouts, interspersed with active recovery at 70% HRR. All exercise sessions were supervised by qualified athletic coach or strength and conditioning coach.
Active Comparator: High Intensity Interval Training×2/wk; Subjects in this group will receive two session of High-Intensity Interval Training per week throughout the 8 weeks experimental period	Behavioral: Exercise intervention; HIIT groups performed 30-meter shuttle runs on a rooftop covered field whereas MICT group ran on a footpath with an overall flat and non-slippery road surface. All training sessions were preceded by a 5-minute self-pace warm-up jogging and ended with a 5-minute self-pace jogging or walking cool-down. Each session of MICT consisted of 30 minutes of continuous exercise at an intensity of 60% of heart rate reserve (HRR); [i.e., (maximal HR - resting HR) × intensity + resting HR]. For each HIIT session, the intensity was set at 90% HRR for high-intensity bouts, interspersed with active recovery at 70% HRR. All exercise sessions were supervised by qualified athletic coach or strength and conditioning coach.
Active Comparator: High Intensity Interval Training×1/wk; Subjects in this group will receive one session of High-Intensity Interval Training per week throughout the 8 weeks experimental period	Behavioral: Exercise intervention; HIIT groups performed 30-meter shuttle runs on a rooftop covered field whereas MICT group ran on a footpath with an overall flat and non-slippery road surface. All training sessions were preceded by a 5-minute self-pace warm-up jogging and ended with a 5-minute self-pace jogging or walking cool-down. Each session of MICT consisted of 30 minutes of continuous exercise at an intensity of 60% of heart rate reserve (HRR); [i.e., (maximal HR - resting HR) × intensity + resting HR]. For each HIIT session, the intensity was set at 90% HRR for high-intensity bouts, interspersed with active recovery at 70% HRR. All exercise sessions were supervised by qualified athletic coach or strength and conditioning coach.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Estimated maximal oxygen consumption	Estimated maximal oxygen consumption achieved during the 20-meter shuttle multistage run test were used for the assessment of aerobic fitness Unit: body weight, estimated oxygen consumption and minute will be combined to report the estimated VO2max in ml/kg/min.	8 weeks
Total running distance	Total running distance in meters achieved during the 20-meter shuttle multistage run test were used for the assessment of aerobic fitness	8 weeks
Total body fat percentage	Total body fat percentage were assessed by a bioelectrical impedance analyzer (BC-418, Tanita, Japan).	8 weeks
Total body fat mass	Total body fat mass in kg were assessed by a bioelectrical impedance analyzer (BC-418, Tanita, Japan).	8 weeks
Total body fat-free mass percentage	Total body fat-free mass percentage were assessed by a bioelectrical impedance analyzer (BC-418, Tanita, Japan).	8 weeks
Total fat-free mass	Total body fat-free mass were assessed by a bioelectrical impedance analyzer (BC-418, Tanita, Japan).	8 weeks
Trunk fat mass	Trunk fat mass in kg were assessed by a bioelectrical impedance analyzer (BC-418, Tanita, Japan).	8 weeks
Body weight	Body weight in kg were assessed by a bioelectrical impedance analyzer (BC-418, Tanita, Japan).	8 weeks
Body height	Body height in meter were assessed.	8 weeks
Body mass index (BMI)	Weight and height will be combined to report BMI in kg/m^2	8 weeks
Waist circumference	Waist circumference was determined to the nearest 0.1 cm of a contact tension tape. The tape was applied directly to the skin at the mid-point between the lower margin of the last palpable rib and the top of the iliac crest.	8 weeks

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Systolic blood pressure	Systolic blood pressure was determined by an electronic sphygmomanometer (Accutorr Plus, Datascope, USA)	8 weeks
Diastolic blood pressure	Diastolic blood pressure was determined by an electronic sphygmomanometer (Accutorr Plus, Datascope, USA)	8 weeks
Mean arterial pressure	Mean arterial pressure was determined by an electronic sphygmomanometer (Accutorr Plus, Datascope, USA)	8 weeks
Resting heart rate	Resting heart rate was determined by an electronic sphygmomanometer (Accutorr Plus, Datascope, USA)	8 weeks
Endothelial function	Endothelial function were measured by digital plethysmography using EndoPAT 2000 device (ITAMAR Medical, Caesarea, Israel) and expressed as natural log reactive hyperemia index (LnRHI)	8 weeks
Arterial stiffness	Arterial stiffness were measured by digital plethysmography using EndoPAT 2000 device (ITAMAR Medical, Caesarea, Israel) and expressed as augmentation index normalized to heart rate of 75 bpm (AI@75)	8 weeks
Serum fasting glucose	Fresh blood samples were sent to an accredited medical laboratory to measure the serum fasting glucose concentrations by commercial test kit methods with an automatic clinical chemistry analyzer (Architect CI8200, Abbott Diagnostics, USA)	8 weeks
Triglycerides	Fresh blood samples were sent to an accredited medical laboratory to measure the serum triglycerides concentrations by commercial test kit methods with an automatic clinical chemistry analyzer (Architect CI8200, Abbott Diagnostics, USA)	8 weeks
High-density lipoproteins (HDL) cholesterol	Fresh blood samples were sent to an accredited medical laboratory to measure the serum high-density lipoproteins-cholesterol (HDL-C) concentrations by commercial test kit methods with an automatic clinical chemistry analyzer (Architect CI8200, Abbott Diagnostics, USA)	8 weeks
Low-density lipoprotein (LDL) cholesterol	Low-density lipoprotein (LDL) cholesterol in serum was measured by an automatic chemistry analyzer (AU-480, Beckman Coulter, USA)	8 weeks
Interleukin 6	Commercially available enzyme-linked immunosorbent assay kits (R&D systems, Minneapolis, MN) were used to determine interleukin 6	8 weeks
Tumor necrosis factor alpha	Commercially available enzyme-linked immunosorbent assay kits (R&D systems, Minneapolis, MN) were used to determine tumor necrosis factor alpha	8 weeks
C-reactive protein	Commercially available enzyme-linked immunosorbent assay kits (R&D systems, Minneapolis, MN) were used to determine c-reactive protein	8 weeks
Adiponectin	Commercially available enzyme-linked immunosorbent assay kits (R&D systems, Minneapolis, MN) were used to determine adiponectin	8 weeks
Intercellular adhesion molecule-1	Commercially available enzyme-linked immunosorbent assay kits (R&D systems, Minneapolis, MN) were used to determine intercellular adhesion molecule-1	8 weeks
Vascular cell adhesion molecule-1	Commercially available enzyme-linked immunosorbent assay kits (R&D systems, Minneapolis, MN) were used to determine vascular cell adhesion molecule-1	8 weeks

Collaborators and Investigators

• Sponsor: The University of Hong Kong

Study record dates

Study Major Dates

• Study Start (Actual): October 1, 2016
• Primary Completion (Actual): August 31, 2017
• Study Completion (Actual): August 31, 2017

Study Registration Dates

• First Submitted: March 31, 2019
• First Submitted That Met QC Criteria: April 3, 2019
• First Posted (Actual): April 5, 2019

Study Record Updates

• Last Update Posted (Actual): April 5, 2019
• Last Update Submitted That Met QC Criteria: April 3, 2019
• Last Verified: April 1, 2019

More Information

Terms related to this study

• Keywords: HIIT; Exercise intensity; Exercise frequency
• Additional Relevant MeSH Terms: Body Weight; Overweight
• Other Study ID Numbers: HIIT001

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No