Mild hyperbaric oxygen: what it is, and what it is not

Mild hyperbaric oxygen is a session in a soft chamber at roughly 1.3 times normal air pressure, breathing air with a higher share of oxygen than usual. That is what Freezlab offers in the AirPod. It is not medical hyperbaric oxygen therapy, which happens in a hospital at twice normal pressure or more, with 100 percent oxygen, to treat specific diagnosed conditions. This article keeps them apart, explains what a session is actually like, and tells you honestly how much the research supports it.

Two things with similar names

Both involve a chamber and both involve oxygen. That is where the overlap ends.

• Medical HBOT. A hard chamber at 2.0 to 3.0 ATA, which is two to three times normal air pressure. The patient breathes 100 percent oxygen through a hood or mask. It runs in a hospital or accredited centre, on prescription, supervised by a physician. Mayo Clinic lists the conditions it is used for: decompression sickness, carbon monoxide poisoning, wounds that will not heal, tissue damage from radiation, sudden hearing loss and a handful of others. Not what Freezlab offers.
• Mild hyperbaric oxygen. A soft chamber at about 1.3 ATA. The air inside is enriched to roughly 35 to 40 percent oxygen, against 21 percent in the room. It is a wellness session, not a treatment. No prescription, no diagnosis, no condition being treated. This is what Freezlab offers.

A wellness chamber cannot do what a hospital chamber does, and we will not tell you it can. Harvard Health and Mayo Clinic both warn about centres marketing chambers for conditions the evidence does not support. We agree with them. If a doctor has told you that you need HBOT, you need a hospital, not us.

What a session in the AirPod is like

1. Before your first visit you complete a health screening at reception. This is not a formality, see the section below.
2. You lie down inside the AirPod. It is a soft chamber, so it feels more like a small tent than a tank.
3. The chamber closes and the pressure rises gradually over a few minutes. Your ears feel it the way they do on a plane. Swallowing or yawning clears them.
4. Then you settle in for 25 or 50 minutes. Most members read, doze or simply lie still. It is quiet in there.
5. The pressure comes back down slowly, the door opens, and you carry on with your day.

A session costs 9 credits, or from €35 as a single.

Most of our members are not athletes. They have full weeks and they want a block of time where nothing is asked of them. That is how most people use the AirPod: a quiet 25 or 50 minutes inside a recovery routine, often after cryotherapy or the Recovery Room. People report feeling rested and clear-headed afterwards. We record that as a report, not a finding.

What the evidence says about mild pressure

Honestly: the evidence is thin here. Most of the research at 1.3 ATA comes from animal studies. A 2019 review by Ishihara in the Journal of Physiological Sciences sums up that work and describes the mechanism: at mild pressure with enriched air, a little more oxygen dissolves in the blood plasma and reaches tissue. That part is basic physics and is not in dispute. Whether that extra oxygen changes anything you can feel or measure in healthy adults is a different question, and the human studies that try to answer it are few, small and mostly without a proper sham group. Our grade: early evidence at best for anything specific. Well established for one thing only, which is that lying quietly for half an hour feels good.

Who should not do it

Mild pressure is mild, but it is still pressure. The clinical guidance for hyperbaric chambers applies in a lighter form, and we take it seriously.

• Untreated pneumothorax (a collapsed lung). This is the one absolute no in every guideline, because trapped air expands when pressure drops.
• Ear or sinus problems. A cold, blocked sinuses, an ear infection or trouble equalising on planes. If your ears will not clear, the pressure can hurt them.
• Recent ear surgery or a perforated eardrum.
• Pregnancy. Not because of known harm at this pressure, but because the data is not there, so we say no.
• Some lung conditions such as poorly controlled asthma or emphysema, and severe claustrophobia.

The full list is on the Mild Hyperbaric Oxygen page and in the screening you complete on your first visit. If anything on it applies to you, tell reception. We would rather you skip a session than push through one.

How it fits into a week at Freezlab

At 9 credits, the AirPod is the biggest single spend in the club, so most members use it once a week or once a fortnight rather than every visit. A common pattern is three minutes of cryotherapy, then 25 minutes in the AirPod to come down and rest. Read the details on the Mild Hyperbaric Oxygen page, check the screening questions, and book a session. New to Freezlab? The Trial Membership covers a few AirPod sessions alongside everything else.

Freezlab does not diagnose, treat or cure medical conditions. If you are unsure whether a therapy suits you, talk to your doctor.