The Effects of Hyperbaric Oxygen Therapy at Intermediate Pressure (1.75 ATA) on VO₂ Max and Inflammatory Cytokine Profiles
Phase: NA
Conditions: Cardiovascular Fitness, Inflammation
Sponsor: University of Texas at Austin

Study Protocol
Official Title:
The Effects of Hyperbaric Oxygen Therapy at Intermediate Pressure (1.75 ATA) on VOI Max and
Inflammatory Cytokine Profiles
ClinicalTrials.gov Identifier:
NCT Number: Pending
Document Date:
December 15, 2025

1. Background and Rationale
Hyperbaric oxygen therapy (HBOT) involves breathing 100% oxygen at pressures greater than
atmospheric pressure. Prior research suggests HBOT may improve cardiovascular fitness and
modulate inflammatory processes. While higher pressures such as 2.0 ATA have demonstrated
physiologic benefits, they may be associated with increased risk and cost. Lower pressures may
provide fewer benefits. Intermediate pressures, such as 1.75 ATA, remain underexplored. This study
aims to evaluate whether HBOT at 1.75 ATA improves aerobic capacity and inflammatory biomarkers
while maintaining an acceptable safety profile.
2. Study Objectives
Primary Objective: To assess changes in VOI max following HBOT at 1.75 ATA.
Secondary Objective: To evaluate changes in circulating inflammatory cytokine profiles following HBOT
at 1.75 ATA.
3. Study Design
This is a prospective, single-arm, pre–post interventional study. Participants will undergo baseline
assessments, receive HBOT intervention, and complete follow-up assessments at prespecified time
points.
4. Study Population
The study will enroll physically active adults aged 30 to 60 years. Participants must be generally healthy
and capable of completing maximal exercise testing. Individuals with medical contraindications to
HBOT or exercise testing will be excluded.
5. Intervention
Participants will undergo 24 hyperbaric oxygen therapy sessions over approximately eight weeks. Each
session consists of exposure to 100% oxygen at 1.75 ATA for 100 minutes, including scheduled air
breaks. All sessions will be conducted in a supervised clinical hyperbaric facility.
6. Outcome Measures
Primary Outcome: Change in VOI max measured via cardiopulmonary exercise testing.
Secondary Outcomes: Changes in circulating inflammatory cytokines measured from venous blood
samples.
7. Study Procedures and Timeline
Assessments will occur at baseline, mid-intervention, immediately post-intervention, and approximately
four weeks after completion of HBOT. Assessments include VOI max testing, blood sample collection,
and vital sign monitoring.
8. Statistical Analysis Overview

Within-participant changes will be analyzed using paired statistical methods. Continuous outcomes will
be summarized using descriptive statistics. Statistical significance will be assessed using appropriate
parametric or nonparametric tests based on data distribution.
9. Safety Monitoring and Ethics
Participants will be screened for contraindications prior to enrollment and monitored throughout the
study. Adverse events will be documented and reviewed by the study team. The study has received
approval from an Institutional Review Board, and all participants will provide written informed consent
prior to participation.