EWOT.
Exercise with oxygen therapy. You train while breathing air with a higher oxygen fraction than the room, which changes how much oxygen reaches working muscle and how hard you can work before your body says no.
- Oxygen enriched air delivered through a mask during exertion
- Studied in randomised trials for exercise capacity and endurance
- Intensity adjusts to any level, including quite modest
- Works through delivery rather than pressure, unlike hyperbaric
More oxygen, while it matters most.
Room air is about 21 percent oxygen. At rest that is more than sufficient, since your haemoglobin is already near saturation. Under hard exertion the picture changes. Oxygen delivery becomes a genuine constraint on what your muscles can do, and in some people arterial saturation actually falls during intense work.
EWOT raises the oxygen fraction of the air you breathe while you exercise. You wear a mask connected to a supply and train on a bike or similar, with the effort scaled to you. The oxygen matters precisely because you are working, which is what separates this from sitting quietly with a cannula.
Mask delivery · intensity scaled to you
Delivery is the constraint.
Four things change when you raise inspired oxygen during exercise, and together they explain why this affects what a session can demand of you.
Arterial Oxygen Rises
Breathing oxygen enriched air raises arterial oxygen content and increases delivery to working muscle. In trained individuals working near maximum, it also prevents exercise induced arterial hypoxaemia, the fall in saturation that occurs at high intensities.
- Increased oxygen delivery to working muscle
- Prevents saturation falling during hard efforts
- Effect is acute rather than stored
Ventilatory Drive Falls
With more oxygen available, the drive to breathe hard drops. Reviews describe improvements as mediated by reduced ventilatory drive allowing better ventilatory efficiency, alongside greater oxygen availability in muscle and brain. The practical result is less breathlessness at the same workload.
- Reduced ventilatory drive at a given intensity
- Improved ventilatory efficiency
- Less perceived breathlessness during work
You Can Work Harder
The literature reports acute effects including improved lactate metabolism, reduced muscle glycogen use, and a higher achievable work rate compared with the same exercise in normal air. In one randomised crossover trial with 32 healthy subjects, endurance time at 75 percent of maximum was substantially longer breathing 50 percent oxygen.
- Higher achievable work rate than in room air
- Improved lactate metabolism reported acutely
- Reduced glycogen utilisation during work
Training Effect Is Separate
That acute performance improves is well supported. Whether training in hyperoxia produces greater long term adaptation than the same training in room air is a separate and less settled question, and reviews describe the effect on VO₂ Max specifically as unclear.
- Acute effect and training effect are different questions
- Effect on VO₂ Max described as unclear in reviews
- The value may be in enabling higher quality work
What is established.
The acute physiology here is well documented. The longer term training question is genuinely open, and those are worth separating.
Acute performance improvement is well supported
A systematic review in the Journal of Applied Physiology reports that randomised trials show normobaric hyperoxia increases exercise performance in healthy subjects. In one crossover trial of 32 subjects, maximal power output rose by 5.3 percent breathing 50 percent oxygen, and endurance time at 75 percent of maximum increased substantially.
The mechanism is understood
Improvements are described as mediated through reduced ventilatory drive allowing better ventilatory efficiency, together with increased oxygen availability in working muscle and in the brain, producing less dyspnoea and greater exercise tolerance. This is physiology rather than conjecture.
Whether it improves training adaptation is less clear
Reviews of hyperoxic training report a likely positive effect on performance compared with normoxic training but an unclear effect on VO₂ Max. The most useful framing may be that hyperoxia lets you complete higher quality work, and the training effect follows from that work rather than from the oxygen itself.
Who tends to use it.
Because intensity scales, this suits a wider range of fitness levels than most people assume.
Athletes wanting to sustain higher quality work within an interval session
People with limited time who want a short session to be genuinely productive
Members returning to training who find breathlessness the limiting factor
Anyone whose exertion tolerance is lower than their willingness to work
Members building the Capacity and Performance system alongside other oxygen work
Screening applies for respiratory and cardiac conditions and during pregnancy
What to expect.
This is a training session rather than a passive one, so arrive prepared to work.
Preparation
- Wear training clothing. You will be exercising
- Tell our team about any respiratory or cardiac condition
- Avoid a heavy meal immediately beforehand
- Mention what else you have trained today so we can set intensity
The Session
- A mask delivers oxygen enriched air while you work
- Intervals of effort alternating with recovery, guided throughout
- You may notice you can hold an effort longer than usual
- Fifteen to thirty minutes depending on your protocol
Afterwards
- The mask comes off and you return to room air immediately
- Expect to have worked. This is exercise, not a treatment
- Rehydrate, and treat it as training within your weekly load
- Typically prescribed two to three times a week
Guided intervals · intensity scaled throughout
Framed as mechanisms, not promises.
Each item describes what this modality is studied in relation to. None is a guaranteed outcome, and individual response varies.
Increased arterial oxygen content and delivery to working muscle
Prevention of exercise induced arterial hypoxaemia at high intensities
Reduced ventilatory drive and improved ventilatory efficiency
Less perceived breathlessness at a given workload
Higher achievable work rate compared with the same exercise in room air
Improved lactate metabolism reported in acute studies
Reduced muscle glycogen utilisation during exercise
Greater exercise tolerance, studied in healthy subjects and clinical populations
Counted as training.
Because this is genuine exertion, it belongs in your weekly training load rather than being added on top of it.
We measure where you are
VO₂ Max establishes your zones and your baseline, which is what makes the intensity here meaningful rather than arbitrary. Screening happens at the same time.
We place it in the week
Scheduled around your other training rather than stacked onto it, at an intensity set to your zones. Typically two to three times a week.
We retest
Your VO₂ Max and other markers are measured again at a defined point, so the effect is visible rather than assumed.
Randomised trials, measured effects.
Hyperoxic exercise has been studied in controlled trials for decades. These are papers on the mechanism and its measured effects, linked so you can read the source.
Improvements under hyperoxia are mediated by a reduction of the ventilatory drive, allowing for better ventilatory efficiency, and by increased availability of oxygen in the working muscles and in the brain, leading to less dyspnoea and greater exercise tolerance.
Hypoxia and hyperoxia on exercise performance
Effects of hyperoxic training on human performance
Hyperoxic-supplemented high intensity interval training
Aerobic intermittent hypoxic training and VO₂ Max
Separate the acute effect from the training effect
Two distinct questions sit inside this literature and conflating them is where most marketing goes wrong. That breathing oxygen enriched air improves what you can do during that session is well supported by randomised trials. Whether training that way produces greater long term adaptation than the same training in room air is less settled, with reviews describing the VO₂ Max effect as unclear. We include a paper arguing against the related hypoxic approach for exactly that reason. Our position is that the value lies in enabling higher quality work, and that the work is what drives the adaptation.
Questions answered.
How is this different from hyperbaric oxygen?
Hyperbaric uses pressure to dissolve oxygen into plasma while you rest. EWOT raises the oxygen fraction of the air while you exercise. Different mechanisms, different demands on you, and they sit in the same system because they address the same chain from different directions.
Do I need to be fit for this?
No. The intensity scales, and for people who find breathlessness the limiting factor, the oxygen often makes moderate work feel more manageable rather than less. We set the level from your baseline testing.
Will this increase my VO₂ Max?
We will not promise that. Reviews describe the effect of hyperoxic training on VO₂ Max as unclear, even while reporting benefits to performance. What we can do is retest yours and show you what actually changed rather than telling you in advance what will.
Is it legal in competition?
Supplemental oxygen is not currently prohibited by the World Anti-Doping Agency. If you compete under a specific governing body, check their rules directly rather than relying on general guidance, including ours.
Does it help with recovery?
The evidence is more mixed than you might expect. One study found hyperoxia during recovery periods interfered with metabolic adaptations following hypoxic exercise. That is why we treat this as a training tool rather than a recovery one, and place it accordingly.
Is it safe?
For most people, at the concentrations and durations used here, and supervised throughout. Screening applies for respiratory and cardiac conditions and during pregnancy. Tell our team about any breathing condition before your first session.
Will I feel different during the session?
Many people report less breathlessness at an effort that would normally leave them working hard for air. Your legs will still know they are working. The oxygen changes the ventilatory side rather than removing the effort.
How often should I do it?
Where prescribed, typically two to three times a week, placed within your training week rather than added to it. This counts as training load.
Is it included in membership?
Access depends on your tier. Circuits are the unit of membership, and which modalities appear in yours is set by your protocol rather than chosen from a menu.
Sequenced deliberately.
Modalities in this system address different parts of the same chain. These are the ones most often paired with it.
Hyperbaric Oxygen
Oxygen delivered under pressure at rest, working the same chain from the delivery side rather than through exertion.
Vasper
Cooled compression training that produces a metabolic stimulus from a short, low impact session.
Oxygen & Capacity
See how this modality sits alongside the others addressing delivery, extraction, and utilization.
Reserve Your Consultation.
Your protocol starts with a conversation and a baseline, not with a modality. In it we will:
- Understand what you are actually training for
- Screen for respiratory and cardiac considerations
- Set intensity from your measured zones rather than by feel
- Explain honestly what the research does and does not show
- Build a protocol across the systems that matter for you