NCT07659301

Brief Summary

This study examines whether exposition to hyperbaric oxygen after a road-race simulation can help competitive cyclists recover and perform better the following day. Hyperbaric oxygen, which involves breathing oxygen inside a pressurized chamber, is used as a recovery method in elite and professional sport. Its effectiveness, however, remains controversial: despite this widespread use, there is a lack of solid scientific evidence that a single HBO session after strenuous endurance exercise actually improves recovery, or that clarifies how the amount of oxygen exposure influences any benefit. The study includes healthy male road cyclists between 18 and 40 years of age who compete at the national level in Belgium. After completing a fatiguing cycling session, each participant is randomly assigned to one of four groups receiving different levels of oxygen exposure during recovery. Two groups breathe oxygen under increased pressure inside a chamber at either 2.5 or 1.4 atmospheres absolute. A third group breathes oxygen at normal pressure. The fourth group receives a sham condition that reproduces the treatment setting without active oxygen exposure. The study is double-blind, meaning that neither the participants nor the researchers assessing the outcomes know which condition each participant receives. The main goal is to determine whether a single session of post-exercise HBO improves next-day endurance performance, and whether higher oxygen exposure produces greater effects. The researchers also collect blood samples and physiological measurements to better understand how the body recovers.

Trial Health

77
On Track

Trial Health Score

Automated assessment based on enrollment pace, timeline, and geographic reach

Enrollment
48

participants targeted

Target at P25-P50 for not_applicable

Timeline
17mo left

Started Jul 2026

Geographic Reach
1 country

1 active site

Status
recruiting

Health score is calculated from publicly available data and should be used for screening purposes only.

Trial Relationships

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Study Timeline

Key milestones and dates

Study Progress6%
Jul 2026Dec 2027

First Submitted

Initial submission to the registry

June 15, 2026

Completed
7 days until next milestone

First Posted

Study publicly available on registry

June 22, 2026

Completed
9 days until next milestone

Study Start

First participant enrolled

July 1, 2026

Completed
1.5 years until next milestone

Primary Completion

Last participant's last visit for primary outcome

December 31, 2027

Expected
Same day until next milestone

Study Completion

Last participant's last visit for all outcomes

December 31, 2027

Last Updated

June 22, 2026

Status Verified

June 1, 2026

Enrollment Period

1.5 years

First QC Date

June 15, 2026

Last Update Submit

June 15, 2026

Conditions

Outcome Measures

Primary Outcomes (1)

  • Next-day endurance performance : Percent decrement in time to exhaustion from baseline

    Endurance performance measured by a cycling time-to-exhaustion test at 105% of the lactate threshold power, expressed as the percentage decrement in time to exhaustion relative to the baseline test. Performance is compared SHAM to the other oxygen-exposure groups.

    Throughout the entire study, approximately during 18 months

Study Arms (4)

HBO 2.5 ATA

EXPERIMENTAL

PiO₂ = 2.5 (100 % O₂ x 2.5 ATA)

Other: Post-exercise Recovery

HBO 1.4 ATA

EXPERIMENTAL

PiO₂ = 1.4 (100 % O₂ x 1.4 ATA)

Other: Post-exercise Recovery

NBO 1.0 ATA

EXPERIMENTAL

PiO₂ = 1.0 (100 % O₂ x 1.0 ATA)

Other: Post-exercise Recovery

SHAM

SHAM COMPARATOR

PiO₂ = 0.21 (21 % O₂ x 1.0 ATA)

Other: Post-exercise Recovery

Interventions

1h intervention after a fatiguing exercise

HBO 1.4 ATAHBO 2.5 ATANBO 1.0 ATASHAM

Eligibility Criteria

Age18 Years - 40 Years
Sexmale(Gender-based eligibility)
Healthy VolunteersYes
Age GroupsAdult (18-64)

You may qualify if:

  • Road cyclists competing in Elite 2 (Elite without professional contract) or Under-23 (U23) categories or equivalent \[Participation in national-level Belgian competitions within the previous 12 months. No specific ranking, finishing position, or performance threshold is required.\]
  • ≥ 2 consecutive years of cycling experience at regional or national level, with structured and periodized training
  • Cycling-specific training volume ≥ 8 h a week over the preceding 10 weeks
  • Measured VO₂max ≥ 60 ml/kg/min

You may not qualify if:

  • Presence of significant cardiovascular, pulmonary, neurological, ENT, or metabolic disease, including but not limited to: Uncontrolled arterial hypertension (systolic blood pressure ≥ 180 mmHg and/or diastolic blood pressure ≥ 110 mmHg) ; Unstable heart disease or decompensated cardiomyopathy
  • Contraindications to hyperbaric exposure, including: Untreated pneumothorax, History of spontaneous pneumothorax without medical clearance ; Pulmonary conditions associated with air trapping (e.g. emphysema or bullous lung disease), or abnormal thoracic imaging when indicated ; Recent thoracic surgery
  • Neurological contraindications, including epilepsy, history of oxygen-induced seizures, or recent seizure activity, and any association with cannabis use
  • Ear, sinus, or Eustachian tube disorders preventing adequate pressure equalization, including active infection or history of severe barotrauma
  • Severe claustrophobia incompatible with chamber exposure

Contact the study team to confirm eligibility.

Sponsors & Collaborators

Study Sites (1)

Institute of Neuroscience, Université catholique de Louvain

Louvain-la-Neuve, Brabant-Wallon, 1348, Belgium

RECRUITING

MeSH Terms

Interventions

Post-Exercise Recovery

Intervention Hierarchy (Ancestors)

Adaptation, PhysiologicalPhysiological PhenomenaExerciseMotor ActivityMovementMusculoskeletal Physiological PhenomenaMusculoskeletal and Neural Physiological PhenomenaAdaptation, BiologicalBiological Phenomena

Central Study Contacts

Théo A MAHY, MSc

CONTACT

Study Design

Study Type
interventional
Phase
not applicable
Allocation
RANDOMIZED
Masking
DOUBLE
Who Masked
PARTICIPANT, INVESTIGATOR
Purpose
TREATMENT
Intervention Model
PARALLEL
Sponsor Type
OTHER
Responsible Party
SPONSOR

Study Record Dates

First Submitted

June 15, 2026

First Posted

June 22, 2026

Study Start

July 1, 2026

Primary Completion (Estimated)

December 31, 2027

Study Completion (Estimated)

December 31, 2027

Last Updated

June 22, 2026

Record last verified: 2026-06

Data Sharing

IPD Sharing
Will not share

Locations