ZoneX measures training zones based on your respiratory gas exchange
Device and software for measuring training zones based on ventilatory thresholds.
ZoneX measure ventilation and CO2 production during a ramp test
ZoneX is a simple, reliable, and accessible device for sports professionals to personalize their athletes' training plans and provide them with optimized instructions to help them achieve their athletic goals.
In the TV show Interieur Sport on Canal+

Tested and adopted by many coaches.

Every week, new tests are posted by our clients on their Instagram accounts and shared on PAIRFS’s account.

A training plan calibrated using ventilatory thresholds leads to 2.2× greater improvement than one based on heart rate reserve.
The study by Wolpern et al. compared two groups over 12 weeks. They followed the same training program, but with different intensity prescriptions.
60% of the group using heart rate reserve did not improve.
100% of the group training based on ventilatory thresholds improved, with an average gain 2.2× greater.

Stop guessing Zone 2
Training in Zone 2 is key to making progress. In the well-known 80/20 model, you should spend 80% of your time there.
With ZoneX, Zone 2 isn’t estimated — it’s measured.
Knowing your Zone 2 is also essential for long-distance events or for weight loss.

A simple and sub max test
With ZoneX, there’s no need to perform maximal tests — you simply need to reach the anaerobic threshold.
The test protocol is a ramp test that requires no mental preparation and isn’t physically exhausting.
Reconnect your clients with testing!
Ventilatory thresholds only — with the reliability of gold-standard systems.
Our approach
Ventilatory thresholds are typically measured using heavy, bulky, complicated, and expensive machines, typically used in hospitals for stress tests or in elite sports centers. These machines can measure many parameters.
With ZoneX, we have created a product focused on a specific measurement because we believe it is the most relevant measurement for physical training. We have simplified the device and adapted the gas sensors specifically for this measurement.
ZoneX makes it easy and accessible to measure ventilatory thresholds without compromising reliability.
Validation of ZoneX vs Cortex
The data from ZoneX has been compared with a reference system.
A study was conducted on 9 participants with HumanFab and is available upon request. It shows that the quality of the data used to determine ventilatory thresholds is equivalent between ZoneX and the Cortex system.
A clinical study is also currently underway to support a scientific publication of these results.
Validation against lactate
Many ZoneX users have also validated the accuracy of ventilatory threshold measurements against lactate testing.



ZoneX was the winner of the Inosport and Ré-éeduca innov' innovation competitions.
ZoneX is designed for sports professionals

Des tests qui peuvent s'enchainer
Le dispositif est conçu pour fonctionner une journée sans être rechargé.
Le masque doit être rincé entre les tests et des tubes internes doivent être changés. Ils peuvent être nettoyés dans de l'eau avec une pilule pour désinfecter

Automatisation du test
Le dispositif est fourni avec un logiciel qui permet de synchroniser des capteurs tiers: puissance, fréquence cardiaque.
Il peut prendre le contrôle d'un home trainer ou d'un tapis de course pour programmer le protocole.
Un test dure entre 15 et 20 minutes avec 5 minutes d'echauffement
Vous pouvez aussi suivre vos propres protocoles

Analyse complète des données
A l'issue du test, le logiciel détermine automatiquement les deux seuils ventilatoires et génère un rapport avec les zones d'entrainements.
Tous les outils sont fournis pour que vous puissiez aussi faire votre propre analyse des données pour trouver les seuils
Product features
The product includes:
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The ZoneX device
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The software that allows you to record and analyze data
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iPhone & Android mobile apps
ZoneX measure expired volume (L/min), tidal volume, respiratory rythm, VCO2 and eqCO2. Measured during a stress test, these data are used to get the ventilatory threshold and get physiological training zones.
15-day money-back guarantee
Software updates included
2-year warranty
Lifespan > 5 years (excluding battery)
There is no maintenance or consumables.
After testing, you must clean the mask and the inner tube. You can use a disinfectant tablet or put it in the dishwasher.

Cycling, running, skating, indoor, outdoor… everything is possible.

Original Protocols
With ZoneX and its software you can perform classic tests... Or not.
ZoneX also offers you the possibility to create your own protocols and analyze your results

ZoneX replaces lactate testing

ZoneX measures physiological training zones in the same way as lactate tests. But it's simpler:
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The effort plateaus are shorter.
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No blood samples are required.
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No sample contamination from sweat.
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ZoneX replaces lactate tests with a simple, less painful, and comprehensive solution.
Our customers are talking about ZoneX
More than 50 coaches and sport professionals are using ZoneX everyday
Kévin Rémondière,
State-certified massage therapist and physical therapist, sports coach
The ZoneX advantage: Ease of use and precision of the device
Aurélien Gabriele
Athlete
ZoneX is a real revolution for anyone looking to understand their physical thresholds accurately and non-invasively.
Michael Lecuivre
Sports coach
One of the most reliable methods for defining your training zones, particularly your HR1/HR2 and HR2/HR3, in a completely personalized way.
XT Xperience training
Personal trainer
I've been a coach for many years and I've integrated PAIRFS into my testing routines for several months now. It has become the ideal tool for evaluating my athletes' ventilatory thresholds: simple to use, reliable, and perfectly suited to both field and lab environments.
I use it regularly with very different profiles, and the result is always the same: a clear protocol, consistent data and real comfort in working.
Honestly, it's a device I really appreciate — well-designed, precise, and above all, consistent over time.
In short: a high-quality product that brings real value to the monitoring of my athletes.



