Oxygen as a Metabolic Modulator: Divergent Physiological Adaptations to Hypoxic and Hyperoxic Tabata Training.

NCT07551869 | Completed DMC

• 1 other identifier: B200-2020-088
• Study Type: interventional
• Target: 23
• Locations: 1 country
• Sites: 1

Brief Summary

The purpose of this study is to examine how breathing air with different oxygen concentrations (higher or lower than normal) during high-intensity interval training affects:

• Aerobic capacity (VO₂max)
• Ventilatory thresholds
• Blood lactate levels
• Perceived exertion This research aims to better understand how oxygen availability influences physiological adaptations to exercise. If you agree to participate, you will undergo the following: Baseline testing:
• Cardiopulmonary exercise test (cycling until exhaustion)
• Measurement of oxygen consumption, heart rate, and ventilatory thresholds
• Blood lactate measurement (finger prick) Training intervention (3 weeks):
• 3 sessions per week (total of 9 sessions)
• High-intensity interval training (Tabata protocol: 8 × 20 seconds effort / 10 seconds rest)
• Exercise performed on an air-resistance cycle ergometer During training, you will breathe either:
• Hyperoxic air (high oxygen concentration) or
• Hypoxic air (low oxygen concentration) You will be randomly assigned to one of these conditions. Post-intervention testing:
• Same assessments as baseline The risks associated with this study are similar to those encountered during high-intensity exercise:
• Fatigue
• Muscle soreness
• Shortness of breath
• Temporary discomfort from finger-prick blood sampling Breathing altered oxygen concentrations (hypoxia or hyperoxia) may induce:
• Mild dizziness
• Increased breathing effort (hypoxia)
• Sensations of ease or altered effort perception (hyperoxia) All sessions are supervised by trained personnel, and safety monitoring is ensured throughout the study You may benefit from:
• Improved physical fitness
• Detailed physiological assessment (VO₂max, thresholds) However, no direct health benefit is guaranteed. Your participation is entirely voluntary.
• You may withdraw at any time
• You do not need to provide a reason
• Withdrawal will not affect your academic or professional standing All collected data will be:
• Anonymized
• Stored securely
• Used only for research purposes Your identity will not be disclosed in any publication. Data will be handled in accordance with applicable data protection regulations (GDPR). You have the right to:
• Access your data
• Request correction or deletion where applicable

Conditions

Hyperoxia / High FiO₂ Exposure; Interval Training; Hypoxia; VO2max; HIIT; High Intensity Interval Training

Keywords

Human; HIIT; High Intensity Interval Training; Assault-Bike; VO2max; Tabata training; Hypoxia; Hyperoxia

Outcome Measures

Primary Outcomes (1)

• maximal oxygen uptake (VO₂max)

  VO2max represents the maximal rate at which an individual can consume oxygen during incremental exercise. It is measured during a graded exercise test (e.g., treadmill or cycle ergometer) using indirect calorimetry. It reflects aerobic capacity and cardiovascular fitness. Higher values indicate better aerobic performance and endurance capacity.

  From enrollment to the end of protocol at 3 weeks

Secondary Outcomes (3)

• the first and second ventilatory thresholds (VT1, VT2)

  from enrollment to the end of the protocol at 3 weeks

• peak blood lactate

  from enrollment to the end of protocol at 3 weeks

• session rating of perceived exertion (RPE).

  from enrollment to the end of the protocol at 3 weeks

Study Arms (2)

Hyperoxia group

EXPERIMENTAL

inspired oxygen fraction (FiO₂) = 0.60 during Tabatha protocol

Other: FIO2 modulation during HIIT protocol on assault bike

Hypoxia group

EXPERIMENTAL

inspired oxygen fraction (FiO₂) = 0.16 during Tabatha protocol

Other: FIO2 modulation during HIIT protocol on assault bike

Interventions

FIO2 modulation during HIIT protocol on assault bike OTHER

Normobaric hyperoxic breathing during high-intensity interval training (FiO2 0.60) and hypoxic (FiO2 0.16)

Hyperoxia group; Hypoxia group

Eligibility Criteria

• Age: 19 Years - 35 Years
• Sex: male
• Healthy Volunteers: Yes
• Age Groups: Adult (18-64)

You may qualify if:

• recreationally active
• male
• years old

You may not qualify if:

• engaged in professional or elite-level sports training
• cardiovascular, pulmonary, metabolic, or neurological disease
• taking medications known to influence cardiovascular or metabolic responses to exercise To minimize potential confounding factors, participants were instructed to refrain from strenuous physical activity, alcohol consumption, caffeine intake, and smoking for at least 24 hours before each testing session, in accordance with standard exercise testing procedures recommended in exercise physiology guidelines

Sponsors & Collaborators

• Haute Ecole Bruxelles-Brabant: lead

Study Sites (1)

Haute Ecole Bruxelles Brabant - HE2B

Brussels, Brussels Capital, 1040, Belgium

Location

Related Publications (3)

• Balestra C, Lambrechts K, Mrakic-Sposta S, Vezzoli A, Levenez M, Germonpre P, Virgili F, Bosco G, Lafere P. Hypoxic and Hyperoxic Breathing as a Complement to Low-Intensity Physical Exercise Programs: A Proof-of-Principle Study. Int J Mol Sci. 2021 Sep 4;22(17):9600. doi: 10.3390/ijms22179600.

  PMID: 34502508 BACKGROUND

• Balestra C, Mrakic-Sposta S, Virgili F. Oxygen Variations-Insights into Hypoxia, Hyperoxia and Hyperbaric Hyperoxia-Is the Dose the Clue? Int J Mol Sci. 2023 Aug 30;24(17):13472. doi: 10.3390/ijms241713472.

  PMID: 37686277 BACKGROUND

• Balestra C, Kot J. Oxygen: A Stimulus, Not "Only" a Drug. Medicina (Kaunas). 2021 Oct 25;57(11):1161. doi: 10.3390/medicina57111161.

  PMID: 34833379 BACKGROUND

MeSH Terms

Conditions

Hyperoxia; Hypoxia

Condition Hierarchy (Ancestors)

Signs and Symptoms, Respiratory; Signs and Symptoms; Pathological Conditions, Signs and Symptoms

Study Officials

• Clément Levêque, PhD

  HE2B

  STUDY DIRECTOR

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: RANDOMIZED
• Masking: NONE
• Purpose: BASIC SCIENCE
• Intervention Model: PARALLEL
• Sponsor Type: OTHER
• Responsible Party: PRINCIPAL INVESTIGATOR
• PI Title: Director of the Integrative Physiology Laboratory , Professor, PhD

Model Details: randomized, two-arm, parallel-group controlled trial

Study Record Dates

• First Submitted: April 5, 2026
• First Posted: April 27, 2026
• Study Start: January 10, 2023
• Primary Completion: June 10, 2023
• Study Completion: December 15, 2025
• Last Updated: April 30, 2026

Record last verified: 2026-04

Data Sharing

• IPD Sharing: Will not share

Locations

BE (1)