Are You Tracking The Wrong Health Markers? | Rick Cohen MD | Uncommon Living Podcast

Summary

Health is not the absence of disease. Health is the capacity to heal from injury or stress--i.e., resilience.

Measures of peak performance like VO2max are poor indicators of resilience, because they do not indicate how hard the body is already working under current stress levels. Resting Breath Hold Index (RBH) is a better indicator of readiness for new stressors.

When health resilience is low, performance degrades, reaction times slow, cognition suffers, and minor tasks require more effort. Dynamic measures of resilience indicate when the body is best prepared for challenges.

Cold plunge therapy can reset the nervous system, restore resilience, and improve stress readiness.

by Rick Cohen MD

Useless Markers of Recovery

I usually wake up feeling pretty good. I don’t need a device to tell me that... but for months I wore one anyway. 

The numbers would shift from day to day. Sometimes it said I was “fully recovered” when I felt flat. Other times it indicated strain when I felt strong. Most days, it didn’t change anything. 

I’d look at the score and still have no sense of the extent to which I was prepared for the challenges of my day. What frustrated me most wasn’t that it was wrong — it was that it didn’t help me decide anything. It gave me numbers, but not guidance.

I saw the same thing with my clients — even high-level athletes. They’d wear these devices religiously, upload the data, and have no idea what to do with it. No one ever changed their training regimen based on a wellness tracker readiness score. 

The advice from the device was always the same: “look at the trends.” But trends aren’t helpful when you need to know how hard to push your training or performance today. 

Stress readiness isn’t a trend — it’s a moment-to-moment reality. And no device was capturing it well.

The Missing Signals

The body can be fueled, rested, and still not ready. I’ve seen it in myself, and I’ve seen it in athletes who are strong, well-trained, fully recovered by the numbers, but off.

The problem is almost never physical capacity--it’s whether the nervous system is actually ready to engage. Most people don’t realize how often there nervous system isn't ready for new stressors.

When the nervous system is strained — from travel, stress, poor sleep, immune load, or just cumulative pressure — nothing works quite right. Your reaction time slows. Your breathing gets shallow. Focus drifts. Tasks feel harder than they should. You’re pushing, but it’s taking more effort to get less done. 

It isn't about how hard you're able to go. It's about your body's ability to accelerate, slow down, and recover. That is, it's about your ability to adapt to stress. When your adaptive capacity is high, we call that resilience, which means your ready for stress. However, when resilience is low your tolerance for stress is also low, and that's when you're at greatest risk of injury or failure.

You can’t feel that directly — not until you’re already overriding.

That’s why I needed a test that could show me my resilience before I made the wrong call about my readiness for stress.

Recovery Measures Do NOT Indicate Resilience

Most people don’t have a real way to assess stress readiness. They either go by how they feel — which can be misleading — or they check their device, glance at the score, and move on.

Even when their device says they’re “recovered,” they rarely change anything. I’ve seen it over and over. The data doesn’t translate into decisions.

The questions that actually matters are: "What do I do today? Do I train hard? Do I back off? Do I take the meeting, run the session, push the work — or is this a day to hold and recover?"

If you guess wrong, it costs you twice. First, your performance takes a hit. Second, your recovery window gets pushed back. What should have been a one-day reset becomes a three-day drag. This happens to athletes constantly — and it’s entirely avoidable.

There is another simple at-home assessment that indicates whether your nervous system is ready for stress. You run it in a minute. No app, no averaging, no overthinking. Just a real-time signal that tells you whether your nervous system is ready — or not.

Once you know that, everything else gets easier.

Resting Breath Hold Index

Resting Breath Hold Index (RBH) is simple. You take a normal exhale and hold your breath. Not a deep breath. Not a big inhale. Just a relaxed breath out, then hold.

You stop when you feel the first real urge to breathe. Not when you’re struggling. Not when you’re gasping. Just when your body says, breathe now — that first internal nudge. That’s the number.

RBH is not a test of lung volume or willpower. Lung volume typically refers to the volume of gas within the lungs and is measured by body plethysmography, gas dilution or washout. Instead, RBH is a direct window into how well your nervous system is managing stress, oxygen, and internal regulation at this moment. It tracks how long your system can stay calm and efficient after a full exhale — no tricks, no pushing.

What it actually measures is your tolerance to rising CO₂ — and how well your brain and nervous system stay composed as that signal builds. When the body is under strain, it reacts sooner. The brain starts to push for air faster. Breathing gets more shallow. The balance between control and reactivity breaks down. The earlier the urge to breathe shows up, the more tension or dysregulation is sitting under the surface. The longer you can stay calm and still, the more available your system is for performance, focus, or recovery. 

This is the signal your devices can’t see, and the one that matters most. RBH picks this up early — before it shows up in performance, mood, or recovery.

How to Do the RBH Test

1. Find a quiet place. Sit upright. Nothing fancy — just grounded and still. Take three slow nasal breaths — in for about 3 seconds, out for about 3 seconds.

2. After the third exhale, just pause. Don’t inhale again. Hold your breath.

3. Start the timer.

4. Hold until you feel the first clear urge to breathe. Not when it’s hard. Not when you’re forcing. Just when the body says, breathe now.

5. Stop the timer. That’s your number.

6. Breathe normally for a minute or so, then repeat once or twice. Log your best score.
   

That’s your Resting Breath-Hold (RBH) Time.

What Your Score Means

The Real Signal: Change Over Time

The number itself matters — but not as much as how it shifts from your normal. An RBH of 50 seconds might be strong for one person — and low for someone else. That’s why the most valuable signal is your daily variation. When it drops, your body is likely under pressure. When it rebounds, recovery has begun. Your baseline tells the story — but the change tells you what to do today.

Change in RBH Is the Signal

The raw number is useful — but the real signal is how it shifts from your own baseline. Most people want to know what a “good” RBH time is. But the truth is, that number means very little without context. A 50-second hold might show up as high resilience in one person — and as a red flag in another.

What matters most is whether your number is stable, dropping, or rebounding.

That’s the difference between seeing a snapshot and reading terrain.

Let’s say your baseline is around 50 seconds after a good night’s sleep. Then, after a cross-country flight, poor sleep, or an emotional hit, you drop to 25. That isn’t just a blip — it’s a real-time signal that your nervous system is under pressure. It’s not adapting well. You’re in a reactive state.

I’ve seen this play out over and over — in clients and in myself. 

For example, my wife — a competitive cyclist — typically holds around 45, but I'm usually closer to 90 seconds. That’s my terrain when things are aligned. 

But after a 4-hour flight from North Carolina to Phoenix, I ran the test and hit 30 seconds. I didn’t feel terrible, but the number told my I wasn't ready to take on more stress, because my nervous system had already been depleted by my flight. If I’d trained hard that day, I would’ve driven the strain deeper and my recovery would’ve taken longer.

When RBH is low, here’s what that usually means:

• CO₂ tolerance is reduced — the body is overreacting to normal breath-hold gas shifts

• Brain oxygenation and blood flow are likely impaired

• Sympathetic (flight or fight) activation is elevated and parasympathetic (rest and digest) function is impaired.

• You’re not in danger — but you’re not regulating.

You might still feel OK when your RBH is low, but what other measures fail to reveal is how hard is your nervous system working to maintain your current state of performance?

That's why RBH is a measure of your readiness for additional stress--i.e., your resilience. It indicates whether your nervous system has the reserve capacity to take on new challenges, or whether it's already overworked.

What Do I Do When RBH Drops?

When RBH is low, I don’t guess. I don’t power through. I reset and retest.

These are the resets I’ve used most consistently:

• CO₂ rehab breathing (5–7 min): nasal only, 4s inhale / 8s exhale. This helps rebalance gas exchange and calm the drive to over-breathe.

• Walking breath-holds (4–6 rounds): gentle exhale → 10–20 second hold while walking → resume nasal breathing. This builds tolerance without forcing.

• Zone 2 movement (20–30 min): light cardio to improve circulation and metabolic flexibility.

• Magnesium bicarbonate: supports energy restoration and parasympathetic tone.

• Circadian anchoring: sun exposure, movement, grounding — especially after travel or rhythm disruption.

• Avoiding stimulants or hard output, until the signal shifts.
  

The key isn’t to do more — it’s to do precisely what’s needed to re-regulate. Sometimes that’s a walk and a breath. Sometimes it’s rest.

After a reset, I’ll run RBH again — usually within 30 to 60 minutes. If it rebounds, I move forward. If it doesn’t, I hold. That’s how I train — and recover — with accuracy.

Ice Baths for Resilience

Ice baths can also reset the autonomic nervous system through activating the sympathetic response and then inducing the parasympathetic response. T his can allow stress to be reduced, improving resilience and breath hold index as a result.

When your body is recovered and not under pressure, the breath-hold stretches naturally. There’s no premature signal to breathe. Nothing is on alert. You’re not fighting anything. 

After my flight, when my RBH was low, I plunged in the freezing ice bath at the Morozko Forge production Studio in Phoenix AZ. After rewarming outside for several minutes, my RBH index jumped from 30 seconds back up to 70 seconds.

That meant I was ready to go.

That's how RBH works. It gives me a clean, moment-based readout of physiological readiness — without effort, and without guesswork.

When you start tracking your RBH, you’ll notice the pattern right away. It drops before you feel off and it rebounds when your body and your nervous system have bounced back and ready for more.

When High Numbers Mislead...

Most of the time, RBH on its own is enough to steer the day with confidence, but sometimes, even a strong RBH score isn’t the green light it looks like. One morning, my resting RBH came in at 120 seconds — a solid number, even for me. But it felt off. There was friction in the hold. It came with more effort than usual.

Something wasn’t right.

For added precision, I’ll use walking breath-holds to see how my body regulates under movement. Normally I’d expect 40+ paces, but on this particular morning, my walking breath hold was below baseline. And I could feel it. Within 10–15 seconds of a walking breath hold, the signal was clear. My body hadn’t fully recovered from the prior day’s load — which had included three breath-holds over four minutes each.

This wasn’t a crash, but it also wasn’t recovery. It was a day where things looked okay on the surface — but underneath, I hadn’t reset. The breath-hold was long, but not clean. The deeper markers were off. Pushing through would’ve made it worse.

So I called it what it was: a hold day. Not a setback, just a clear signal to give the body space to settle.

I adjusted:

• Morning walk in the sun.

• Gentle yoga and movement.

• No cold exposure.

• No stimulants, no emotional load.

• Magnesium bicarbonate as needed.
  

This is where RBH becomes powerful. It doesn’t just tell you when to go — it tells you when to wait. And it keeps you from being tricked by numbers that look good but carry friction underneath.

Avoid Your Ego

There’s always a temptation to beat your last breath-hold. To chase the number. But that’s not the point.

That’s what I call terrain ego — pushing to prove you’re ready, even when your body says otherwise. You’re overriding the signal instead of responding to it. 

I’ve done it. Everyone does. But over time, I’ve learned: when I listen, I recover. When I push past the signal, I pay for it. RBH gives you the stop sign before the cost shows up.

What To Do Next?

Try the test. Track your number. Then do it again tomorrow. You’ll start to notice patterns — not just in the number itself, but in how it lines up with how you recover, train, and show up. That’s where the real value lives.

This is the starting point of a broader stress readiness model — one that adapts to you, instead of locking you into a plan that doesn’t flex. It doesn’t require wearables, apps, or averages. Just attention and consistency. 

About the Author

Rick Cohen MD is was educated as a biomedical engineer prior to earning his doctorate in medicine and becoming a physician. His research and practice is focuses on rearchitecting human resilience using his understanding of quantum biology, mitochondria, and regenerative system design.