Does Training While Breathing Extra Oxygen Improve Fitness?
Not proven. This review’s conclusion is that much is known about the acute effects of breathing hyperoxia while the effects of hyperoxia-supplemented training are not well understood. The authors report that the few studies on training with supplemental oxygen have produced conflicting results.
Training while breathing more oxygen has become practical because athletes can now wear a mask and breathe a higher fraction of oxygen from a stationary or portable apparatus while they exercise. This review by Cardinale and Ekblom examines what that does acutely and what it does over a training block.
What the Data Show
The review separates two questions that often get blurred together:
- Acute effects: A large body of evidence indicates that oxygen transport capacity, lactate metabolism, power output and work tolerance are improved while breathing hyperoxia.
- Training effects: The few studies on the physiological effects of hyperoxic training have been conducted with conflicting results.
- Adaptation mechanisms: How the body adapts to hyperoxia-supplemented training is not well understood, especially in well-trained endurance athletes.
- Safety: Potential detrimental effects have not been shown experimentally, and the authors call for further investigation.
The proposed mechanisms behind the acute performance improvements are higher oxygen delivery and reduced central fatigue, though the authors state these are still not fully elucidated.
Dr. Kumar’s Take
The distinction this review draws is the one that matters clinically. Breathing extra oxygen during a session makes that session better: more oxygen delivered, less lactate accumulation, more power, longer time to exhaustion. That part is well supported. Whether stacking those better sessions into weeks of training produces an athlete who performs better afterwards in normal air is a separate question, and the evidence there is conflicting rather than positive. I would not sell an athlete on hyperoxic training as a proven adaptation tool. I would describe it accurately as an acute aid whose long-term training value is still open, and I would want the safety question answered before anyone uses it habitually.
How Hyperoxic Training Works
When you breathe extra oxygen during exercise:
- Oxygen delivery to working muscle rises, which is one of the two mechanisms the authors propose
- Central fatigue is reduced, the second proposed mechanism
- Oxygen transport capacity improves
- Lactate metabolism improves
- Power output and work tolerance improve, so endurance during the session is greater
The reasoning behind hyperoxic training is that these acute benefits let an athlete work at a higher intensity, and that the larger training stimulus should carry over to performance in normal air. The review does not find that this carryover has been established.
The Evidence
Acute hyperoxia is the well-documented part of this literature. Hyperoxia-supplemented endurance training is not: the review describes the available training studies as few in number and conflicting in their results, and the mechanisms behind any training adaptation as poorly understood. That gap is widest in well-trained endurance athletes, which is exactly the group most likely to want to use the technique.
Important Limitations
- The training studies it draws on are few, and they disagree with each other
- The mechanisms of adaptation to hyperoxic training remain unresolved
- Evidence in well-trained endurance athletes is especially thin
- Potential detrimental effects have not yet been shown experimentally
Practical Takeaways
- A large body of evidence indicates that breathing hyperoxia during a session improves power output, lactate metabolism and work tolerance in that session
- Whether weeks of hyperoxic training improve later performance in normal air is unsettled
- The equipment side is straightforward: a mask fed by a stationary or portable oxygen apparatus
- Anyone considering habitual use should know the safety data are incomplete rather than reassuring
Related Studies and Research
- Hyperbaric oxygen therapy and cancer, a review
- Oxygen therapy in traditional and immunotherapeutic treatment protocols of cancer patients: current reality and future prospects
- Tumor oxygenation and survival rates (22 sarcoma patients)
- The Effects of Hyperoxia on Sea-Level Exercise Performance, Training, and Recovery: A Meta-Analysis
FAQs
How is hyperoxia delivered during training?
Athletes wear a mask and breathe a higher fraction of oxygen supplied by a stationary or portable apparatus while they exercise.
Does breathing extra oxygen help during the session itself?
Yes. A large body of evidence shows improved oxygen transport capacity, lactate metabolism, power output and work tolerance while breathing hyperoxia.
Is hyperoxic training safe?
Potential detrimental effects have not been shown experimentally, and the authors say the question warrants further investigation. Work with qualified professionals.
Does hyperoxic training make you faster once you go back to normal air?
That is the unresolved part. The few studies examining hyperoxia-supplemented endurance training have produced conflicting results, and the mechanisms behind any adaptation are not well understood.
Bottom Line
This review makes a clean split between two claims that often travel together. Breathing hyperoxia during exercise improves oxygen transport capacity, lactate metabolism, power output and work tolerance, and the likely mechanisms are greater oxygen delivery and reduced central fatigue. Training over weeks with supplemental oxygen is a different proposition, and the studies that have tested it disagree, with the adaptation mechanisms still unexplained and potential detrimental effects not yet shown experimentally. Treat hyperoxic training as an open question, not a settled method.
