PNEO · FROM HUMAN PERFORMANCE CENTER

PNEO™ (pronounced “NEE-oh”) — derived from the Greek word pneuma, meaning breath and spirit.

Train the signal behind every breath.

Your CO₂ tolerance is the hidden metric behind calm, focus, and athletic endurance. Pneo™ measures it, trains it, and tracks your progress — in as little as 60 seconds a day.

Download on the App Store Take the CO₂ test →
20–60
seconds–minutes
6+
free + pro
iOS 17+
built for
Pneo app home screen

BUILT BY CLINICIANS, NOT A TECH STUDIO

“Most breathwork apps train you to feel calm. We built one that trains the nervous system to be calm — measurably.”

Kele & Fred McDaniel · HPC, Santa Fe NM · Practicing since 1999

humanperformancecenter.com →

SECTION 01 · THE WHY

Most of us breathe 20,000 times a day without thinking about it. That’s the problem.

CO₂ Tolerance Test
Measure your breath-hold capacity
Take 4 calm prep breaths, then exhale in a slow, controlled stream — not a breath hold. We’ll time how long you can keep air moving out.
<20s Low 20-50s Moderate >50s High

Try it now — take the CO₂ Tolerance Test.

This one-minute test measures how calmly your nervous system handles CO₂. It’s the single number Pneo™ uses to calibrate everything.

How it works
1
4 calm prep breaths — we guide the timing
2
Exhale slowly — a thin, steady stream through your nose or pursed lips. Keep air moving out (not a breath hold).
3
Tap when you need to breathe in — don’t force it. Stop at the first urge.
  • Lower resting breath rate and deeper tidal volume
  • Improved autonomic regulation and vagal tone
  • Greater exercise capacity and delayed ventilatory threshold
  • Reduced anxiety triggers from normal CO₂ fluctuations

SECTION 02 · THE METHOD

Strength training for your respiratory system.

The 4-Week Program progressively loads your CO₂ tolerance the same way a strength program loads your muscles — structured sets, measured progress, and systematic adaptation. Each week builds on the last.

Pro only

1

Week 1 — Baseline

Establish your CO₂ score and learn nasal-diaphragmatic mechanics.

2

Week 2 — Load

Introduce extended exhale holds and CO₂ builder sets.

3

Week 3 — Adapt

Personalized sessions calibrated to your improving tolerance.

4

Week 4 — Integrate

Full protocol with advanced holds and recovery-phase breathing.

SECTION 03 · INSIDE THE APP

Three modules. One purpose.

03 modules · 06 techniques · 1 score

MODULE 01

Free

Breathing Techniques

Six guided protocols for focus, calm, sleep, and activation. Each session is timed, paced with haptic cues, and designed around clinical breathing mechanics.

MODULE 02

Pro

CO₂ Training

Measure your CO₂ tolerance with a one-minute exhale test, build tolerance with the CO₂ Builder, and unlock Personalized CO₂ sessions that adapt to your level. The core of the app.

MODULE 03

Free

Learn

Short-form education on breathing mechanics, CO₂ science, and the “why” behind each protocol — written by clinicians, not copywriters.

Use Pneo™ free. Train with Pro.

Two paths, one app. Start free, go deeper when you’re ready.

FREE · FOREVER

Everything to start.

$0
 
  • 6 guided breathing techniques
  • CO₂ Test (one-time baseline)
  • CO₂ Builder sessions
  • Full Learn library
Pneo free experience
Download free
Recommended PRO · 3-DAY FREE TRIAL

Everything to progress.

$4.99/mo
Annual $49.99/yr · Lifetime $99.99
  • Personalized CO₂ Training
  • 4-Week Structured Program
  • Advanced Analytics & trends
  • All future protocols included
Pneo Pro paywall
START FREE TRIAL

No content library. No endless features. Just the practice.

Home screen
HOME
CO2 Test
CO₂ TEST
Relax
RELAX
4-Week Program
4-WEEK PROGRAM

COMPARE PLANS

Free is real. Pro is personal.

 
$0 Forever
$4.99/mo Recommended
Focus / Relax / Sleep / Activate
✓
✓
CO₂ Test (one-time)
✓
✓
CO₂ Builder
✓
✓
Personalized CO₂
—
✓
4-Week Program
—
✓
Learn library
✓
✓
Future protocols
—
✓

QUESTIONS

Frequently asked

01
What is CO₂ tolerance?
Your body’s ability to stay calm as CO₂ builds up between breaths. Higher tolerance = slower, deeper, more efficient breathing — and a more regulated nervous system. We measure it with a one-minute timed exhale — a slow, controlled stream, not a breath hold.
02
How long are sessions?
From 60 seconds (the daily test) to 20 minutes (program sessions). The shortest path to a benefit is consistency, not duration.
03
Do I need to know how to breathe a special way?
No. The app guides you through every inhale, hold, and exhale in each technique — and in the Learn section, it teaches you the correct mechanics for proper breathing so you build the right habits from the start.
04
Is this safe?
For most healthy adults, yes. If you’re pregnant, have a heart condition, or are managing anxiety in active treatment, talk to your clinician first. Pneo™ is a wellness app, not a medical device.
05
What’s HPC?
Human Performance Center — an integrative therapy practice in Santa Fe, NM, founded in 1999. Pneo™ is the first piece of software we’ve built; it distills the breath protocols we use in clinic.

Breathe better. Live calmer.

Twenty thousand breaths a day. Pneo™ trains the system that runs them.

Download on the App Store Try the CO₂ test