Origin
Why This Program Exists
Three established breathing traditions are based on the same mechanisms. Our program makes it accessible for everyone.
The Person Behind It
Why This Exists
I trained as a Buddhist monk for nine years, then spent 18 years as a Buteyko breathing instructor. Early on, I taught the strongest version of the method. It was impressively effective, but the intensity made it harder to sustain on the long-term. I adapted the approach to give people more control over their own intensity and encouraged lower intensity for long term results, but the question stayed with me: if the strongest version works best, is there no way to make it easier to do?
Over the last ten years, I took an increasingly experimental attitude to the practice. I was particularly interested in variants that allow higher training effectiveness while being softer on the nervous system. Getting closer to the nervous system required changes to the exercises that are not possible within the Buteyko framework.
It also required a completely new app with new exercise flows and a larger selection of exercise variants. The new app uses sensor-free stress detection to find your optimal intensity. Zones make the invisible visible. No equipment needed. And relaxation puts you in the best position to make a serious effort, once you're properly warmed up. Based on the new exercise style, we also developed a walking version, allowing you to practice in a more physically active way.
A Hard Problem to Solve
Three established breathing traditions independently discovered that breathing less delivers more oxygen to the cells. Each tradition developed effective training methods. Two of them couldn't scale. The third one scaled but lost the ability to adapt to individual differences.
In yoga, pranayama with extended breath retention is the most advanced practice, the culmination of years of dedicated training. The practitioners who reach that level are genuine masters. The problem is that this path requires a long-term teacher-student relationship and years of preparation. Very few yoga teachers reach or teach the deeper pranayama. What the masters achieve is real, but the way to get there does not scale.
Buteyko researchers proved the mechanism: CO₂ tolerance drives oxygen delivery. Research confirmed strong results. But the full original version of the method required skill and judgment that Buteyko found very hard to transfer to new instructors. It took too long. He said himself that after a full year of training, only about 2% had the ability. So he made a simpler, weaker version of the method. That version scaled worldwide. The original results stayed locked behind rare expertise.
Modern tummo (the 30-breath method) showed that millions of people will hold their breath if given a simple framework. That was a genuine breakthrough, and it entered popular consciousness in a way no breathing method had before. But many people find it doesn't fit. The deep hyperventilation, the breath hold style, and the cold exposure come as a fixed package with no room to adapt. It reached a mass audience, but it doesn't meet people where they are.
Each tradition solved part of the problem. None solved all of it.
Research
Stanescu et al. 1981, J Appl Physiol
60% more efficient CO₂ response
Breathing training recalibrates the CO₂ response
The Reuvers program is designed to improve your CO₂ response over months and years.
Three Traditions, One Mechanism
Research
Dallam et al. 2018, Int J Kinesiology & Sports Sci
Same VO₂max, better breathing economy
Nasal breathing improves running economy
The Reuvers program trains nasal breathing from the first session.
All three breathing traditions train the same underlying physiology: the ability to maintain calm, efficient breathing while CO₂ rises. In physiology, this is called CO₂ tolerance. When CO₂ tolerance is high, oxygen flows freely from the blood to the cells. More oxygen from less air.
Pranayama trains it through graduated breath retention (kumbhaka). Buteyko trains it through reduced breathing and extended pauses. Tummo trains it through breath holds after intense breathing. Different entry points. Same destination.
The research confirms that this mechanism is not tradition-specific. It is human physiology.
60 Years of Evidence
The evidence spans six decades, multiple countries, and thousands of participants. The findings are consistent: when breathing training specifically targets CO₂ tolerance and oxygen efficiency, results are strong across sleep, stress, focus, and physical performance.
Research
Lundberg et al. 1995, Nature Medicine
Significant nasal nitric oxide release
Nose breathing produces nitric oxide
Nasal breathing is the default throughout the Reuvers program.
Research
Hurford et al. 1990, J Appl Physiol
+9.5% hemoglobin from breath-hold diving
Breath-hold diving lifts hemoglobin
The same breath-hold response is trained gradually and safely in the app.
Research
Schagatay et al. 2001, J Appl Physiol
+30.5% longer breath-hold time
Repeated breath holds extend how long you can hold
Every session trains progressively longer, relaxed holds.
Research
Engan et al. 2011, Scand J Med Sci Sports
Spleen-driven red blood cell release
Apnea training builds the body's oxygen-carrying response
Breath-hold sequences in the Reuvers program's higher levels.
Why This Stayed Rare
Research
de Bruijn et al. 2008, Eur J Appl Physiol
+24% EPO after repeated breath holds
Repeated breath holds raise erythropoietin (EPO)
Breath-hold sequences run through every level of the Reuvers program.
The research is clear. The mechanism is proven. The results are strong. So why hasn't oxygen efficiency training become standard practice?
Because the strongest version requires real-time calibration. Push too hard and the nervous system activates, undermining the CO₂ tolerance you are trying to build. Push too little and nothing changes. The right intensity is different for every person and shifts session to session.
Traditional instruction depends on the instructor's judgment to find this balance. That judgment takes years to develop. According to Buteyko himself, after a full year of instructor training, only about 2% of new instructors could deliver the method at the quality level needed for best results.
The limitation is an exercise customization problem. People need options to adjust the exercise to what works for them. And the exercise itself needs to detect when something isn't working and signal that a change is needed. Both of these are solvable with the right technology.
Get the Foundation Right
Every session trains three things: your breathing muscles, your oxygen efficiency, and your ability to focus and relax.
When you get the foundation right, everything else follows.
The App That Measures What Instructors Used to Guess
Research
Glubokaya et al. 2021, Bulletin of Tula State University
1 km run 7-8 seconds faster after 5 months
Breath-hold training improves running performance
Breath-hold training in the Reuvers program's higher levels builds the same adaptation.
The Reuvers method came from open experiment, and its core is real-time stress and performance measurement built into the exercise. The app reads your breathing response after each breath hold. What matters is how your nervous system reacted afterward, more than how long you held.
A long hold followed by gasping scores red. A moderate hold followed by smooth recovery scores green. You know immediately whether you pushed too hard or not hard enough. Practice intensity is measured in every round.
The training adapts to you automatically through built-in feedback loops. The app reads your response, adjusts intensity, and tracks progress over time. This feedback loop works without needing a physical sensor. Just a new and smarter approach to analyzing your breathing sessions.
Instructors supplement the app with broader guidance: managing side effects, the bird's eye view of your training, walking exercises, and higher-level techniques. The app handles moment-to-moment calibration. The instructor handles the bigger picture.
For the full evidence base, see the research page.
View the research →