Effects of Whole-Body HIIT and Moderate Continuous Exercise on Immune Function (WBHIIT-IMM)

Effects of Whole-Body High-Intensity Interval Training and Moderate-Intensity Continuous Exercise on Immune Function in Recreationally Active Men

This randomized controlled trial aimed to investigate the effects of a 12-week Whole-Body High-Intensity Interval Training (WB-HIIT) program compared with Moderate-Intensity Continuous Training (MICT) on immune function in recreationally active young adults. Participants were randomly assigned to either WB-HIIT or MICT groups. Immune-related biomarkers and performance outcomes were assessed before and after the intervention. The study sought to determine whether different exercise modalities produce distinct adaptations in immune function.

Study Overview

• Status: Completed
• Conditions: Exercise Physiology; Exercise Immunology
• Intervention / Treatment: Behavioral: Whole-Body High-Intensity Interval Training (WB-HIIT); Behavioral: Moderate-Intensity Continuous Training (MICT)

Detailed Description

This study was designed as a two-arm, parallel-group, randomized controlled trial. A total of 20 recreationally active male participants were randomly assigned to either the Whole Body High-Intensity Interval Training (WB-HIIT) group or the Moderate-Intensity Continuous Training (MICT) group. The intervention lasted 12 weeks and involved supervised training sessions multiple times a week.

The WB-HIIT protocol consisted of repeated high-intensity whole-body exercises performed at near-maximum effort with intermittent rest periods, while the MICT group performed moderate-intensity continuous aerobic exercise. Immune function was assessed through selected hematological and biochemical markers collected at baseline and post-intervention. In addition, physical performance variables were evaluated to examine secondary adaptations to different exercise modalities. The primary aim of the study was to compare the effects of WB-HIIT and MICT on immune system responses, while secondary outcomes included changes in exercise performance. This study provides insights into how different training intensities affect immune regulation in individuals who are active in their leisure time.

• Study Type: Interventional
• Enrollment (Actual): 20
• Phase: Not Applicable

Contacts and Locations

Study Locations

• Turkey (Türkiye)
  • Merkez
    • Bitlis, Merkez, Turkey (Türkiye), 13100
      • Bitlis Eren University

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: Yes

Description

Inclusion Criteria:

Healthy male adults Aged 18-25 years Not engaged in regular structured exercise training (>3 sessions/week) VO₂max within normal healthy range Willingness to participate and provide informed consent No acute or chronic inflammatory, metabolic, or cardiovascular disease

Exclusion Criteria:

Female participants (not included in study design) Smoking or alcohol abuse Use of anti-inflammatory or immunomodulatory drugs Participation in regular high-intensity training programs Musculoskeletal limitations preventing exercise testing or training Acute infection within last 2 weeks Chronic metabolic, cardiovascular, or autoimmune diseases

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: None (Open Label)

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: Whole-Body HIIT; Participants will perform Whole-Body High-Intensity Interval Training (WB-HIIT) protocol.	Behavioral: Whole-Body High-Intensity Interval Training (WB-HIIT); Whole-body high-intensity interval training protocol performed under supervision.
Active Comparator: MICT; Participants will perform Moderate-Intensity Continuous Training (MICT) protocol.	Behavioral: Moderate-Intensity Continuous Training (MICT); Moderate-intensity continuous training protocol performed under supervision.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Peripheral immune cell counts	Changes in peripheral blood leukocyte, lymphocyte subsets, neutrophil, and monocyte counts from baseline to post-intervention (8 weeks).	Baseline and 8 weeks (post-intervention)

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Inflammatory cytokine levels	Changes in serum IL-6, TNF-α, and CRP levels from baseline to post-intervention (8 weeks).	Baseline and 8 weeks (post-intervention)
Immunoglobulin levels	Changes in serum immunoglobulin (IgA, IgG, IgM) concentrations from baseline to post-intervention (8 weeks).	Baseline and 8 weeks (post-intervention)
Cortisol levels	Changes in serum cortisol levels as a marker of exercise-induced stress response from baseline to post-intervention (8 weeks).	Baseline and 8 weeks (post-intervention)
Maximal oxygen uptake (VO₂max)	Changes in VO₂max measured by cardiopulmonary exercise testing from baseline to post-intervention.	Baseline and 8 weeks (post-intervention)

Collaborators and Investigators

• Sponsor: Bitlis Eren University
• Investigators: Principal Investigator: Melih Çalışır, PhD, Bitlis Eren Üniversitesi University

Study record dates

Study Major Dates

• Study Start (Actual): June 30, 2020
• Primary Completion (Actual): August 30, 2020
• Study Completion (Actual): August 30, 2020

Study Registration Dates

• First Submitted: May 16, 2026
• First Submitted That Met QC Criteria: May 23, 2026
• First Posted (Actual): June 1, 2026

Study Record Updates

• Last Update Posted (Actual): June 1, 2026
• Last Update Submitted That Met QC Criteria: May 23, 2026
• Last Verified: May 1, 2026

More Information

Terms related to this study

• Keywords: High-intensity interval training; immune system; cortisol; IL-6; ACTH; moderate-intensity continuous exercise; exercise immunology
• Other Study ID Numbers: 2020-189

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO
• IPD Plan Description: Individual participant data will not be shared due to participant privacy and confidentiality concerns.

Drug and device information, study documents

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