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

NCT ID: NCT03904810

Last Updated: 2019-04-05

Basic Information

• Recruitment Status: COMPLETED
• Clinical Phase: NA
• Total Enrollment: 103 participants
• Study Classification: INTERVENTIONAL
• Study Start Date: 2016-10-01
• Study Completion Date: 2017-08-31

Brief Summary

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.

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.

Conditions

Overweight and Obesity

Study Design

• Allocation Method: RANDOMIZED
• Intervention Model: PARALLEL
• Primary Study Purpose: TREATMENT
• Blinding Strategy: SINGLE

Study Groups

Control

Subjects in this group do not received any intervention

Group Type: NO_INTERVENTION

No interventions assigned to this group

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

Group Type: ACTIVE_COMPARATOR

Exercise intervention

Intervention Type: BEHAVIORAL

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.

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

Group Type: ACTIVE_COMPARATOR

Exercise intervention

Intervention Type: BEHAVIORAL

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.

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

Group Type: ACTIVE_COMPARATOR

Exercise intervention

Intervention Type: BEHAVIORAL

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.

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

Group Type: ACTIVE_COMPARATOR

Exercise intervention

Intervention Type: BEHAVIORAL

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.

Interventions

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.

Intervention Type: BEHAVIORAL

Eligibility Criteria

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.

• Minimum Eligible Age: 18 Years
• Maximum Eligible Age: 30 Years
• Eligible Sex: MALE
• Accepts Healthy Volunteers: No

Sponsors

The University of Hong Kong

OTHER

Sponsor Role: lead

Responsible Party

Parco M. Siu, PhD

Associate professor

Responsibility Role: PRINCIPAL_INVESTIGATOR

Locations

LKS Faculty of Medicine

Hong Kong, , Hong Kong

Countries

Hong Kong

Other Identifiers

HIIT001

Identifier Type: -

Identifier Source: org_study_id