HIIT, Cardiorespiratory Fitness, and Metabolic Health in Healthy Young Adults

NCT07719296 | Completed DMC

• 1 other identifier: HIIT-MET-STUDENTS
• Study Type: interventional
• Target: 29
• Locations: 1 country
• Sites: 1

Brief Summary

The purpose of this study was to investigate the effects of a high-intensity interval training (HIIT) intervention on cardiorespiratory fitness (CRF) and cardiometabolic health in active male university students. The main question it aims to answer is: Does HIIT improves CRF and cardiometabolic outcomes, including blood pressure, lipid profile, and insulin resistance estimated using the homeostasis model assessment of insulin resistance (HOMA-IR). Researchers will compare HIIT (designed to experimental group) to non-training intervention (designed to control group) to see if the training program works to improve the cardiometabolic health status. The HIIT program consisted of three sessions per week for 9 weeks, comprising of three sets of six to eight 30-second running bouts performed at 100-110% of maximal aerobic speed (MAS), interspersed with 30-second active recovery runs at 50% MAS between bouts.

Conditions

Metabolic Health; Cardio Respiratory Fitness

Keywords

Training period; Aerobic fitness; Young adults; Insulin resistance; Lipid profile; Cardiometabolic health

Outcome Measures

Primary Outcomes (7)

• Insulin resistance

  Insulin resistance was estimated by the homeostasis model assessment (HOMA-IR) index as HOMA-IR = (fasting insulin (mU/l) × fasting glucose (mmol/l) / 22.5)) (Matthews et al., 1985).

  One day before the start and two days after the completion of the 09 weeks of training program.

• Total cholesterol

  Total cholesterol concentration, expressed in mg/dL, was assessed by the enzymatic method on an Architect C8000 auto analyzer (Abbott Laboratories, Abbott Park, IL) using respective reagent kits.

  One day before the start and two days after the completion of the 09 weeks of training program.

• Triglyceride

  Triglyceride concentration, expressed in mg/dL, was assessed by the enzymatic method on an Architect C8000 auto analyzer (Abbott Laboratories, Abbott Park, IL) using respective reagent kits.

  One day before the start and two days after the completion of the 09 weeks of training program.

• Blood pressure

  Blood pressure, expressed in mmHg, was measured after 15 minutes of seated rest using an automatic blood pressure monitor (Omron BP652; Omron Healthcare Inc., Vernon Hills, IL, USA).

  One day before the start and two days after the completion of the 09 weeks of training program

• Cardiorespiratory fitness

  Cardiorespiratory fitness was assessed using the Vameval incremental running test performed to exhaustion (Cazorla, 1999). Maximal aerobic speed (MAS) was determined from the highest running speed achieved during the test, and maximal oxygen consumption (VO2max) was estimated using the standard Vameval protocol (Cazorla, 1999). The Vameval test is a validated field test for assessing aerobic capacity in healthy young adults.

  One day before the start and two days after the completion of the 09 weeks of training program.

• Body mass index

  Body mass index (BMI), expressed in kg/m², was calculated from measured body mass (kg) and height (m) using the standard formula: BMI = body mass (kg) / height² (m²). Body mass and height were used only to derive BMI and were not considered separate outcome measures.

  One day before the start and two days after the completion of the 09 weeks of training program

• Body fat percentage

  Body fat percentage (%) was estimated from four skinfold measurements (bicipital, triceps, subscapular, and suprailiac) using the Durnin and Womersley (1973) method.

  One day before the start and two days after the completion of the 09 weeks of training program.

Secondary Outcomes (4)

• Fasting glucose

  One day before the start and two days after the completion of the 09 weeks of training program.

• Insulin

  One day before the start and two days after the completion of the 09 weeks of training program.

• High-density lipoprotein cholesterol

  One day before the start and two days after the completion of the 09 weeks of training program.

• Low-density lipoprotein cholesterol

  One day before the start and two days after the completion of the 09 weeks of training program

Study Arms (2)

High-intensity interval training (HIIT) group

EXPERIMENTAL

The HIIT group performed a HIIT program consisting of three sessions per week for 9 weeks, including three sets of six to eight bouts of 30-second runs at high intensity \[100-110% of maximal aerobic speed (MAS)\], interspersed with 30-second recovery runs at low intensity (50% MAS) between bouts, in line with recommendations by Ouerghi et al. (2017, 2026) in young males.

Behavioral: High-intensity interval training (HIIT) program

Control group

NO INTERVENTION

The participants in the control group maintained their normal daily activities.

Interventions

High-intensity interval training (HIIT) program BEHAVIORAL

The HIIT program consisted of three sessions per week for 9 weeks, comprising of three sets of sixr to eight bouts of 30-second runs at high intensity \[100-110% of maximal aerobic speed (MAS)\], interspersed with 30-second recovery runs at low intensity (50% MAS) between bouts.

High-intensity interval training (HIIT) group

Eligibility Criteria

• Age: 19 Years - 25 Years
• Sex: male
• Healthy Volunteers: Yes
• Age Groups: Adult (18-64)

You may qualify if:

• Male university students at the High Institute of Sport and Physical Education, Kef, Tunisia.
• Aged 19 to 25 years
• Provided written informed consent

You may not qualify if:

• Acute or chronic disease contraindicating vigorous physical exercise
• Musculoskeletal injury or any other medical condition limiting participation in exercise
• Participation in another structured training program within the previous 6 months
• Current or recent (within the previous 3 months) use of medications or dietary supplements that could influence the study outcomes

Sponsors & Collaborators

• High Institute of Sports and Physical Education of Kef: lead

Study Sites (1)

Tunisia

El Kef, Boulifa, 7100, Tunisia

Location

MeSH Terms

Conditions

Insulin Resistance

Interventions

High-Intensity Interval Training

Condition Hierarchy (Ancestors)

Hyperinsulinism; Glucose Metabolism Disorders; Metabolic Diseases; Nutritional and Metabolic Diseases

Intervention Hierarchy (Ancestors)

Physical Conditioning, Human; Exercise; Motor Activity; Movement; Musculoskeletal Physiological Phenomena; Musculoskeletal and Neural Physiological Phenomena

Study Officials

• Nejmeddine Ouerghi, Ph.D

  Research Unit "Sport Sciences, Health and Movement"(UR22JS01) High Institute of Sport and Physical Education of Kef, University of Jendouba, 7100 Kef, Tunisia.

  PRINCIPAL INVESTIGATOR

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: RANDOMIZED
• Masking: NONE
• Purpose: PREVENTION
• Intervention Model: PARALLEL
• Sponsor Type: OTHER
• Responsible Party: PRINCIPAL INVESTIGATOR
• PI Title: Principal Investigator

Study Record Dates

• First Submitted: July 17, 2026
• First Posted: July 22, 2026
• Study Start: December 1, 2025
• Primary Completion: February 16, 2026
• Study Completion: February 16, 2026
• Last Updated: July 23, 2026

Record last verified: 2026-07

Data Sharing

• IPD Sharing: Will not share

Locations

TU (1)