What You’ll Learn
- Why 5.5 seconds in and 5.5 seconds out is the “magic number” for resonant frequency breathing, backed by James Nestor’s research [01:09]
- How HRV serves as the key indicator that you’ve hit your personal resonant breathing pattern [02:00]
- The Patrick McKeown pilot study showing 8-11% VO2 max increases in athletes within 4-6 weeks of breathwork training [16:43]
- Why the urge to breathe comes from CO2 tolerance, not oxygen levels, and how to train it [26:59]
- How downregulating breathing speeds up athletic recovery by 46%, according to clinical research [22:49]
- The BOLT score test: how to benchmark your CO2 tolerance at home (40+ seconds is a good score) [17:58]
- Why mouth breathing in children changes facial and dental structure over time [43:57]
- How music entrains your breathing rate, which drives the physiological effect, not neurological pathways [50:20]
- Wim Hof’s E. coli study: how 12 trained individuals repelled infection through sympathetic activation breathing [40:10]
- FivePointFive’s AI coach feedback, heart rate tracking, and 4 difficulty levels for personalized breathwork [58:03]
Why It Matters
Most people assume they know how to breathe because they’re alive. Adam Ludwin argues the opposite. The vast majority of us breathe dysfunctionally every single day, contributing to chronic stress, suppressed immunity, and poor athletic performance.
Functional breathwork isn’t the “woo woo” spiritual practice many associate with the term. It’s a data-driven, clinically validated tool that professional athletes use to boost VO2 max, accelerate recovery by 46%, and regulate their nervous systems on demand. Patrick McKeown’s pilot study with athletes demonstrated 8-11% VO2 max gains in just 4-6 weeks from breathwork alone, without increasing training load.
The kicker: you only need five minutes a day, five times a week. That’s less time than most people spend scrolling social media before breakfast. Whether you’re an elite competitor or someone who wants better sleep and lower stress, understanding your breath gives you the fastest lever to shift your nervous system state in under 90 seconds.
Who Should Listen
- Athletes and fitness enthusiasts looking to increase VO2 max, speed up recovery, and maintain nose breathing during high-intensity training
- Biohackers and wearable users who track HRV, sleep quality, and recovery scores but haven’t yet connected breathwork to those metrics
- Stress-prone professionals who want a rapid, evidence-based tool to downregulate their nervous system in under 90 seconds
- Parents curious about how breathing habits shape children’s facial structure, dental health, and stress resilience
- Anyone skeptical of breathwork who needs clinical data and athlete testimonials before committing to a practice
Episode Overview
Adam Ludwin sold his tech company Captify Technologies in 2021, then discovered functional breathwork through James Nestor’s book Breathe. That discovery led him to study under Patrick McKeown, one of the world’s top functional breathwork experts. Now he’s built FivePointFive, a data-driven breathwork app that bridges the gap between elite athlete coaching and everyday wellness.
The conversation opens with the science behind resonant frequency breathing: 5.5 seconds in, 5.5 seconds out, 5.5 breaths per minute. This isn’t arbitrary. HRV data confirms when you’ve hit your personal sweet spot. Ludwin explains how FivePointFive tracks heart rate via Bluetooth wearables and Apple Watch, then uses AI coaching to provide real-time feedback on your breathing performance.
From there, the discussion moves into VO2 max. Ludwin references a Patrick McKeown pilot study showing athletes gained 8-11% VO2 max in 4-6 weeks through breathwork exercises stacked on top of their existing routines. The mechanism involves CO2 tolerance training, diaphragm activation, and expanded lung capacity. All three are trainable without altitude camps or expensive equipment.
Recovery gets significant attention. Clinically proven downregulating breathing (longer exhales than inhales) speeds recovery by 46%. Ludwin shares how even top triathletes rely on the app primarily for post-workout cooldowns. He sees recovery as the dominant wellness trend moving forward.
The episode also covers CO2 tolerance (why the urge to breathe comes from carbon dioxide, not lack of oxygen), mouth taping at night using Patrick McKeown’s Myotape, how mouth breathing reshapes children’s facial structure, and the Wim Hof E. coli experiment where 12 trained individuals repelled infection through sympathetic activation.
Ludwin wraps by walking through FivePointFive’s features: 4 difficulty levels, AI coach feedback, music genre selection, and a science section behind every class. He offers code URBAN for a 7-day trial (normally 3 days).
Key Terms
- [01:09] Resonant frequency breathing: The optimal breath rate (approximately 5.5 seconds in, 5.5 seconds out) where your cardiovascular, respiratory, and nervous systems synchronize. Confirmed via HRV measurement.
- [02:00] HRV (Heart Rate Variability): The variation in time between heartbeats. A key biomarker for autonomic nervous system balance, recovery status, and stress resilience. Sub-metrics include RMSSD (mind) and SDNN (mind and body).
- [13:53] VO2 max: The maximum amount of oxygen your body can utilize during high-intensity exercise. A gold-standard marker of cardiovascular fitness and longevity.
- [26:59] CO2 tolerance: Your body’s ability to handle rising carbon dioxide levels before triggering the urge to breathe. Higher tolerance correlates with lower resting heart rate, better performance, and improved breathing efficiency.
- [17:58] BOLT score (Body Oxygen Level Test): A self-assessment of CO2 tolerance. Exhale normally, hold your breath, and count seconds until the first diaphragm contraction. 40+ seconds indicates good tolerance.
- [15:45] Diaphragm activation: Engaging the primary breathing muscle (located under the rib cage) by expanding the ribs outward rather than belly breathing. Critical for core stability, respiratory efficiency, and injury prevention.
- [39:04] Autonomic nervous system balance: The interplay between sympathetic (fight-or-flight) and parasympathetic (rest-and-digest) states. Functional breathwork trains the ability to shift between both on demand.
How Does Resonant Frequency Breathing Improve HRV?
The short answer
Breathing at your resonant frequency (around 5.5 breaths per minute) synchronizes your cardiovascular and respiratory rhythms. This creates the largest possible oscillations in heart rate variability, essentially training your autonomic nervous system to be more flexible and resilient.
What Ludwin found
Adam Ludwin discovered the concept through James Nestor’s book Breathe, which identified 5.5 seconds in, 5.5 seconds out as the sweet spot for most humans. But Ludwin emphasizes it’s an average. Some people resonate at 4.5 seconds, others at 6.5. The only way to confirm your personal resonant rate is through HRV data.
FivePointFive tracks two key HRV sub-metrics: RMSSD (reflecting parasympathetic activity and mental state) and SDNN (a broader indicator of mind and body status). When you hit resonance, both metrics spike. Over time, regular practice at your resonant frequency raises your baseline HRV, which is associated with better recovery, deeper sleep, and lower chronic stress.
Ludwin’s team recommends five sessions per week, five minutes each. Their data shows that consistency at this frequency produces measurable HRV improvements. One key insight: your resonant frequency shifts as your fitness changes. Someone training for a marathon will have different breath patterns than someone focused on stress management. That’s why FivePointFive integrates biometric tracking rather than prescribing a one-size-fits-all protocol.
Heart rate monitoring during sessions provides a real-time proxy for nervous system state. As Ludwin explains, heart rate is an indicator of future HRV. By understanding your heart rate response during breathwork, you can predict and shape your HRV trajectory over weeks and months.
What to do about it
- Start with 5.5-second inhales and 5.5-second exhales for 5 minutes. Use a wearable or the FivePointFive app to track your heart rate response.
- Experiment with breath rates between 4.5 and 6.5 seconds per phase. Your optimal rate is the one that produces the largest HRV swing.
- Practice 5 days per week at minimum. Consistency matters more than session length.
- Track trends over weeks, not days. HRV fluctuates daily based on sleep, stress, and training load.
“Wellness in general shouldn’t just be a feeling anymore. We’re past that. You should be getting data.” – Adam Ludwin, FivePointFive founder
Related: HRV Training: The Complete Guide
Can Breathwork Actually Increase VO2 Max?
The short answer
Yes. A pilot study by Patrick McKeown (FivePointFive’s lead advisor and one of the world’s top functional breathwork experts) showed athletes gained 8-11% VO2 max in 4-6 weeks by stacking breathwork exercises on top of their existing training. No additional physical training load required.
What Ludwin found
Ludwin breaks the mechanism into three pathways. First, CO2 tolerance training simulates altitude training. When athletes train at high altitude, they build carbon dioxide tolerance, boosting red blood cell production and oxygen transport via hemoglobin. Breathwork replicates this effect through nose breathing during high-intensity exercise and targeted breath holds. You don’t need to fly to Kenya.
Second, diaphragm activation improves respiratory efficiency. A stronger diaphragm means easier oxygen transportation and better core stability. Third, lung capacity exercises wake up dormant alveoli (tiny air sacs in your lungs) and can physically expand total lung volume over time. Free divers train this way for a reason.
Ludwin also notes that VO2 max benefits compound with better sleep and recovery practices. The three pathways don’t work in isolation. They amplify each other.
What to do about it
- Practice nose-only breathing during zone 2 training. Build up gradually toward higher zones.
- Add breath holds during workouts to simulate altitude training and build CO2 tolerance.
- Train your diaphragm: lie flat post-workout, place a weight on your diaphragm, and breathe against the resistance.
- Do full inhale/exhale breathing exercises to expand lung capacity and activate dormant alveoli.
“They saw a 8 to 11% increase in VO2 max in a 4 to 6 week period when doing these types of exercises.” – Adam Ludwin, referencing Patrick McKeown’s pilot study with athletes
Related: How to Breathe Properly
Why Is CO2 Tolerance More Important Than Oxygen Intake?
The short answer
Your cells already carry 97-98% oxygen saturation, even after exercise. The urge to breathe doesn’t come from needing more oxygen. It comes from rising CO2 levels. Training your CO2 tolerance is the real lever for better breathing, lower resting heart rate, and improved performance.
What Ludwin found
Most people believe they breathe to get more oxygen. Ludwin calls this a fundamental misconception. Our blood oxygen saturation barely changes during most activities. What triggers the breathing reflex is your body’s sensitivity to carbon dioxide buildup. If you panic at the first hint of CO2 accumulation, you’ll breathe faster, shallower, and less efficiently.
Training CO2 tolerance through breath holds, nose breathing during exercise, and controlled air hunger teaches your body to stay calm with higher CO2 levels. The result: slower resting breathing rate, decreased resting heart rate, and better oxygen delivery through the Bohr effect (where CO2 actually helps release oxygen from hemoglobin to tissues).
Ludwin recommends the BOLT score test as a starting benchmark. Breathe normally, exhale, hold, and count to the first diaphragm contraction. Forty seconds or above is a good score. Retest periodically to track progress.
What to do about it
- Take the BOLT score test today to establish your CO2 tolerance baseline.
- Practice nose breathing during all zone 1-2 exercise. Gradually extend to higher intensities.
- Add moderate air hunger intervals: breathe normally, then hold after an exhale until you feel a moderate urge to breathe. Build gradually.
- Mouth tape at night using Myotape or a simple vertical strip of micropore tape to reinforce nasal breathing during sleep.
“The urge to breathe comes from your carbon dioxide tolerance. Our cells have 97, 98 oxygen in them.” – Adam Ludwin, FivePointFive founder
Related: Box Breathing: The Complete Guide
The Ludwin Functional Breathwork Protocol
- Check your baseline: take the BOLT score test (normal exhale, hold, count to first diaphragm contraction). Record your score. 40+ seconds is the target.
- Find your resonant frequency: start at 5.5 seconds inhale, 5.5 seconds exhale. Adjust between 4.5 and 6.5 seconds per phase while monitoring HRV response.
- Commit to the minimum effective dose: 5 minutes per day, 5 days per week. Consistency drives measurable HRV and recovery improvements.
- Activate your diaphragm correctly: place hands on the bottom sides of your ribs. Breathe so ribs expand outward (not belly forward). Post-workout, lie flat and place a weight on your diaphragm to train it.
- Train CO2 tolerance during exercise: breathe through your nose only during zone 1-2 training. Gradually extend nose breathing into higher zones as tolerance builds.
- Use downregulating breathing for recovery: inhale for 4 seconds, exhale for 8 seconds (or similar ratio with longer exhales). Apply immediately post-workout and before sleep.
- Mouth tape at night: use Myotape or a small vertical strip of micropore tape to reinforce nasal breathing during sleep. This accelerates daytime nose breathing adaptation.
- Track and compare your data: connect a wearable via Bluetooth to monitor heart rate during sessions. Review HRV trends weekly, not daily.
- Match breathwork to your goal: use performance builders (CO2 tolerance, breath holds) before training. Use cooldowns (longer exhales, slow breathing) for recovery. Use sleep classes before bed.
- Retest your BOLT score every 2-4 weeks to confirm measurable progress in CO2 tolerance.
*Source: Adam Ludwin’s Functional Breathwork Framework, FivePointFive*
Frequently Asked Questions
What is resonant frequency breathing & why does 5.5 breaths per minute matter?
Resonant frequency breathing is the rate at which your cardiovascular, respiratory, and nervous systems synchronize for optimal function. For most people, this falls around 5.5 seconds in and 5.5 seconds out (approximately 5.5 breaths per minute). When you hit this rate, HRV reaches its peak oscillation. Your personal resonant rate may differ slightly, ranging from 4.5 to 6.5 seconds per phase, so tracking HRV data is the only way to confirm your ideal rate.
How long does it take to see results from functional breathwork?
Adam Ludwin recommends 5 minutes per day, 5 days per week as the minimum effective dose. FivePointFive’s data shows measurable improvements in HRV and recovery metrics at this frequency. Patrick McKeown’s pilot study with athletes showed 8-11% VO2 max gains in 4-6 weeks. CO2 tolerance can improve noticeably within the first 1-2 weeks of consistent practice.
What is a good BOLT score & how do I test it?
A good BOLT score is 40 seconds or above. To test it, take a few normal breaths, exhale normally (not forcefully), then hold your breath and count the seconds until you feel the first diaphragm contraction or urge to breathe. Do not push past that first urge. The purpose is to benchmark your CO2 tolerance and retest every 2-4 weeks to track improvement.
Can breathwork replace altitude training for VO2 max improvement?
Breathwork can simulate key benefits of altitude training without traveling to high elevations. CO2 tolerance training through nose breathing during exercise and controlled breath holds increases red blood cell production and oxygen transport, similar to what happens at altitude. Combined with diaphragm activation and lung capacity exercises, these techniques produced 8-11% VO2 max gains in Patrick McKeown’s pilot study with athletes.
Is mouth taping at night safe & what tape should I use?
Mouth taping at night is generally considered safe for healthy adults. Adam Ludwin and host Nick Urban both use a small vertical strip of micropore tape rather than covering the entire mouth. Patrick McKeown’s Myotape is a child-friendly option that tapes around the mouth, allowing it to open if needed. You can still breathe through your mouth in an emergency. The goal is to reinforce nasal breathing during sleep, which improves CO2 tolerance and accelerates daytime breathing improvements.
How does FivePointFive differ from other breathwork apps?
FivePointFive focuses exclusively on functional (science-backed) breathwork rather than traditional or spiritual practices. It integrates real-time heart rate tracking via Bluetooth wearables and Apple Watch, provides AI coach feedback after each session, and offers 4 difficulty levels (beginner through advanced). The app includes a science section behind every class and tailors recommendations based on your mind, body, and sleep scores. Use code URBAN for a 7-day trial.
Products, Tools, & Resources Mentioned
*Outliyr independently evaluates all recommendations. We may get a small commission if you buy through our links (at no cost to you). Thanks for your support!*
- FivePointFive App (code URBAN for 7-day trial, normally 3-day): Data-driven functional breathwork app with AI coach feedback, heart rate tracking, and 4 difficulty levels. Available on iOS in the US. Get FivePointFive
- Ultrahuman Ring (code URBAN saves 10%): Wearable ring for HRV, sleep, and recovery tracking. Get the Ultrahuman Ring
- Breathe by James Nestor: The book that introduced Adam Ludwin to the 5.5-second resonant frequency concept. Covers the science and history of nasal breathing. Get Breathe on Amazon
- Myotape by Patrick McKeown: Child-friendly mouth tape that wraps around (not over) the mouth to promote nasal breathing during sleep. Learn more about Myotape
- Oura Ring: Popular HRV and sleep tracking wearable. Note: not currently compatible with FivePointFive’s heart rate tracker. Learn more about Oura Ring
About Adam Ludwin
Adam Ludwin is a serial entrepreneur who sold Captify Technologies in 2021. After discovering functional breathwork through James Nestor’s Breathe, he studied under Patrick McKeown, one of the world’s leading functional breathwork experts and author of 13-14 books on the subject. McKeown now serves as FivePointFive’s lead advisor, alongside Dr. Jay Wiles (HRV expert who trains world-class athletes).
Ludwin built FivePointFive to democratize the data-driven breathwork coaching previously available only to elite athletes with personal coaching teams. The app integrates real-time biometric tracking, AI feedback, and clinically validated techniques across performance, recovery, and sleep. He practices what he preaches: 5 minutes of breathwork every morning, daily ice baths, and consistent wearable tracking.
Related Episodes & Articles
- E72: HRV Biofeedback Training with Dr. Jay Wiles
- Othership Breathwork App: Science & Benefits
- Breathwork & Meditation Frameworks with David Reveles
- Vagus Nerve Stimulation User Guide (Pulsetto)
- Human Performance & Recovery: DARPA Research
- Article: HRV Training: The Complete Guide
- Article: Breathe Properly
Music by Alexander Tomashevsky
Full Episode Transcript
Adam Ludwin [00:00:00]: And clinically proven, you can speed up recovery by 46% by doing like down regulating breathing.
Nick Urban [00:00:04]: So you’re listening to High Performance Longevity, the show exploring a better path to optimal health for those daring to live as an outlier in a world of averages. I’m your host, Nick Urban, bioharmonizer, performance coach, and lifelong student of both modern science and ancestral wisdom. Each week we decode the tools, tactics and timeless principles to help you optimize your mind, body and performance span. Things you won’t find on Google or in your AI tool of choice. From cutting edge biohacks to grounded lifestyle practices, you’ll walk away with actionable insights to look, feel and perform at your best across all of life’s domains. Adam, welcome to the podcast.
Adam Ludwin [00:00:57]: Thanks. Thanks for having me.
Nick Urban [00:00:58]: A mutual friend introduced us and he mentioned what you were working on. I saw the title of your platform, the name 5.5. What does that refer to and why is that significant?
Adam Ludwin [00:01:09]: Yeah, so 5.5, I actually discovered it whilst reading the book Breathe by James Nestor. And he basically talks about the optimal breath for a human being somewhere between 4.5 seconds in, 4.5 seconds out, and 6.5 seconds in, 6.5 seconds out, and obviously averaging out to 5.5 seconds. But there’s more to it than that because it’s also 5.5 seconds in, 5.5 seconds out, but also 5.5 breaths per minute and 5.5 liters of air. So there’s this magic number of 5.5 has been floating around for a long time. That being said, that’s an average. Right. So some people’s optimal breath will be four and a half, and some people may be six or six and a half, but, uh, it’s kind of the magic number for ultimate breathing for a human.
Nick Urban [00:01:52]: Okay. And so when you hit your what’s called resonant frequency breath rate, what happens? What’s going on inside your body that makes it a magic number?
Adam Ludwin [00:02:00]: Yes. So I think from a physiological standpoint, obviously certain breathing techniques have different reactions to different people. But when you look at the key metric that you find when you hit that sweet spot is hrv, that’s kind of a really key indicator that you’re, you’re getting that resonance breathing pattern that is right for you. That being said, that also changes over time. Right. So we know that, you know, if you’re training for a marathon or you’re going to train in a certain way, your breath patterns also evolve. So it’s incredibly important from a biometric standpoint that Wherever tall people are using, which is why we’ve got biometrics in the app that we have, is to really measure not just where you are today, but also how you’re evolving over time and ensuring that ultimate breath pattern from balancing out your nervous system is working as it should. And that obviously has a whole host of benefits that I’m sure we’ll talk about in a lot of detail in this podcast.
Nick Urban [00:02:52]: Yeah, so if I figured out my resonant frequency breath rate right now is say, average of 5.5 or 4 in, 6 out, and that changes over time. What do I do with that information? Like, how do I use that to actually make a change and how do I know if it’s a good change or a bad change?
Adam Ludwin [00:03:10]: So I think there’s core biomarkers that everyone will monitor from our perspective, from an athletic perspective, a lot of people are focused on VO2 Max and HRV. There is obviously a benchmark. So not everyone has the same levels of these biomarkers. So over time, you’ll start to compare against your own benchmark. So if you’re having apps, be that Whoop or a Fitbit Garmin, the benchmark is obviously incredibly important because it’s obviously telling you where you were at and how you’re doing compared to that. And what we also find is, you know, people do try and compare each other and it’s just a dangerous game because, you know, we are all different, but you will start to see so many different effects as you kind of evolve in that journey. So let’s take, for example, hrv. You know, that obviously has multiple benefits from a body perspective, a mind perspective, a sleep perspective.
Adam Ludwin [00:04:01]: So you can start to measure the sub metrics from all those. When you start to go into measuring deep sleep versus REM versus other forms of sleep. So wherever you’re starting, you can go deeper and deeper and get kind of a better understanding of how much data you want. And I think these wearables that exist, they’re not short of data. Right. You can go into a real rabbit hole and some people just like the top line data and they’ll focus on HRV VO2 max. And some people really want to get under the hood. So if you’re looking at hrv, there are multiple data points that fall under hrv, where we often look at rmssd, which is a really good indicator from a mind perspective what’s going on at sdnn, which also is used for a mind and body perspective.
Adam Ludwin [00:04:44]: So these sub biomarkers, which a lot of wearables give you, but maybe the frequency isn’t as often as it should be. That’s really insightful if you want to get a level deeper as well into some of those metrics.
Nick Urban [00:04:57]: Interesting. There’s also one called, I think it’s a coefficient of variants of HRV which is more resistant to like heart rate changes because I think it’s as your heart rate increases or increases, your HRV also increases. And so there’s more research around the code, the CV of HRV as it’s abbreviated for performance and other things. Maybe you’ve seen that.
Adam Ludwin [00:05:20]: Yeah, well, there’s multiple types of hrv. Right. So there’s the short term hrv, long term hrv, standard hrv. And you know, if you’re, if you’ve gone for a run, you see your hrv, it’s not going to look like what it’s going to look in the morning, but actually when you look at following morning, that’s actually when you’re seeing the benefits of it. So yeah, so it’s again, knowing kind of your routine, knowing how you’re working out, knowing when you’re looking at them and not expecting kind of like to see certain results after a certain activity is one thing, but understanding which level of HRV you’re actually looking at is another thing.
Nick Urban [00:05:51]: Because HRV is also one of those metrics where it can be really helpful. And I’ve been talking a lot about nervous system regulation on the podcast and it’s really like the core of like behavior change and of health. If you have a disregulated nervous system, things that are, quote, otherwise healthy are going to actually not work in your favor. They can work against you. And so knowing your nervous system status is great. But then if you’re working out frequently, you might notice your HRV declines. And it’s really about like the bigger picture rather than just like a 24 hour cycle. Is it high today, low tomorrow? It’s like that’ll be very, that’ll fluctuate a lot depending on what you’re doing.
Nick Urban [00:06:25]: So it’s like understanding the trends and like you don’t want to see your HRV constantly low because you’re working out super hard. That might also be a negative thing sign. So you want to see like a good and.
[Full transcript continues in the audio. Listen above or on your favorite podcast platform.]
Adam Ludwin [01:09:09]: Yeah, well, we, we do support it on the heart rate tracker at the moment, but, but we just don’t support it. So there’s two sections I should add real quickly. Sorry. The heart rate tracker integratable into kind of all major wearables apart from Aura right now. But the, the performance section, which is like a mind, body and sleep score that’s under beta right now. So that’s only integrating with Apple Watch for the time being. But you know, in the next kind of four to six weeks we’re going to be bringing in other wearables into that as well. But you can still kind of get kind of.
Adam Ludwin [01:09:39]: Yeah, all the kind of good stuff from those types of wearables as well.
Nick Urban [01:09:42]: Okay, well, look forward to checking that out. Thanks Adam.
Adam Ludwin [01:09:45]: Thanks so much for having me. Appreciate it.
Nick Urban [01:09:47]: Thanks for tuning in to high performance longevity. If you got value today, the best way to support the show is to leave a review or share it with someone who’s ready to upgrade their health span. You can find all the episodes, show notes and resources mentioned at outlier.com. until next time, stay energized, stay bioharmonized, and be an outlier.
