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Hyperbaric Oxygen Linked to Fitness Gains in 1,032 Patients

A large patient cohort saw measurable gains in aerobic capacity after hyperbaric oxygen therapy, a pattern previously shown in smaller controlled trials.

By Dr. Josh Axe · November 11, 2026 · 1 source · Watch

Photo: Pexels

At a glance

What they found: 94% improved on peak or threshold oxygen uptake.
Who was studied: 1,032 patients with varied health conditions, treated with hyperbaric oxygen therapy from 2018 to 2025.

A cohort of 1,032 patients who completed hyperbaric oxygen therapy showed a 2.29 mL/kg/min rise in peak aerobic capacity, according to a study published November 11, 2026 in Frontiers in Aging.

82.9%showed some gain

58.8sessions average

1,032patients tracked

Researchers tracked 1,032 consecutive patients with varied health conditions who underwent hyperbaric oxygen therapy from 2018 to 2025, each completing cardiopulmonary exercise testing before and after treatment. Patients completed an average of 58.8 sessions at 2.0 atmospheres with intermittent air breaks. Peak aerobic capacity (VO2 max) rose 2.29 mL/kg/min (95% CI, 2.10-2.47), and the oxygen-use threshold during submaximal exercise rose 2.12 mL/kg/min (95% CI, 1.94-2.30). Oxygen pulse, a measure of oxygen delivered per heartbeat, rose 0.79 mL/beat, and ventilatory efficiency improved, with the VE/VCO2 slope falling 1.07. All seven fitness markers tracked improved at the group level. Using MET-based thresholds, 53.9% of patients gained at least half a MET in aerobic capacity, 26.6% gained a full MET or more, and 82.9% showed some increase; 94.4% improved on peak or threshold oxygen uptake. The authors call this the largest such cohort reported, extending smaller placebo-controlled trials of the same hyperoxic-hypoxic paradox protocol into a larger real-world population with mixed conditions.

Cardiorespiratory fitness is among the strongest markers tied to biological aging and long-term survival, which is why the authors emphasized VO2 max and ventilatory threshold as headline measures. Higher aerobic capacity reflects how efficiently the heart, lungs and muscles deliver and use oxygen during exertion; this study didn't test which organ system drove the improvement.

Peak Aerobic Capacity Change After Hyperbaric Oxygen Therapy

Frontiers in Aging, 2026, Yaakobi et al.

This was a retrospective, uncontrolled cohort with no comparison group, so changes are linked to hyperbaric oxygen therapy, not proven caused by it. The authors state prospective controlled studies are needed to determine the therapy's specific contribution versus other factors in patients' care.

Dr. Axe’s Take

A 2.29 mL/kg/min rise in peak aerobic capacity across more than 1,000 patients with mixed health conditions is a meaningful signal, especially since VO2 max tracks closely with how long and well people live. I'd pair any interest in hyperbaric oxygen with the basics that build aerobic capacity on their own: zone 2 cardio several times a week, strength training, and nasal breathing during easy efforts. This was an uncontrolled cohort, so I wouldn't assume the chamber alone did the work. If chronic illness or stalled fitness has you considering it, find an experienced provider to discuss appropriate protocols.

— Dr. Axe

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Study summary

Who: 1,032 consecutive patients with varied clinical conditions, ages under 45 to 75 and older, both sexes, treated 2018-2025.
Design: Retrospective cohort study; within-subject before-and-after comparison using cardiopulmonary exercise testing, benchmarked against prior sham- and control-anchored trials.
Dose: Hyperoxic-hypoxic paradox protocol, 2.0 atmospheres absolute with intermittent air breaks, averaging 58.8 sessions per patient.
Primary result: Peak aerobic capacity (VO2 max/kg) rose 2.29 mL/kg/min (95% CI 2.10-2.47); 82.9% of patients showed some increase.
Secondary: Ventilatory threshold capacity rose 2.12 mL/kg/min; oxygen pulse rose 0.79 mL/beat; ventilatory efficiency slope fell 1.07; 26.6% gained at least 1 MET.
Funding / conflicts: Funding and conflicts not reported in the abstract.
Date: Nov 11, 2026