Breath Test

The CO2 Tolerance Test is a gateway to understanding your physiology. Developed through extensive trials and applications, including in conjunction with Stanford University’s Huberman Lab; this test has been proven to be a powerful indicator of a variety of physiological mechanisms and gives strong indicators of anxiety levels and even breath mechanics to some degree.

Carbon Dioxide tolerance is important because:

  • CO2 and water along with energy (in the form of ATP) is the exhaust of your aerobic metabolism. When you work harder, breath rate and volume go up.
  • Respiration increases as a result of energy, and CO2 accumulation. Therefore you need to rid yourself of more CO2 depending on how tolerant or intolerant of it we are.
  • Your ability to go through metabolic pathways has a lot to do with how well your body can tolerate CO2 and the acid processes that can “stress” the system as it navigates its way up or down.
  • C02 Tolerance is a great indicator of stress and inflammation

Follow the directions below to find your current CO2 Tolerance. Then you can use your time to calculate personalized Apnea and Cadence Breathing Protocols. Retest every 2-3 weeks to measure your progress and calibrate your personal protocol to your current state.

Over time your CO2 tolerance and your breath practice, in general, can serve as powerful indicators of reactivity to stressors (whether training or otherwise) and how your physiology is dealing with those stressors.

Directions for Test:

Find a stopwatch (on most phones)
Take 3-5 deep normal breaths
Relax for 10 seconds
Take 1 more full inhale, and when you start to exhale, start your timer
Exhale as long and slow as you can
Record your time and input below in the Apnea and Cadence Calculators for personalized breathing protocols

What does your test result mean?

>80 seconds –> Elite. Reflects an advanced pulmonary adaptation, excellent motor control, and low arousal.
60-80 seconds –> Advanced. Reflects a healthy pulmonary system, good motor control, and relatively low arousal.
40-60 seconds –> Intermediate. This range generally improves quickly with a focus on CO2 tolerance training.
20-40 seconds –> Average. Moderate to high arousal state. Breathing mechanics need improvement.
<20 seconds –> Poor. Very high arousal and stress sensitivity. Mechanical restriction possible. Poor pulmonary capacity.

If you would like more information on how and when to use these breathing patterns check out the State app (iOS & Android) for very specific, personal breath work protocols, the PSE PRO Plus Breathe programs or sign up for an Art of Breath clinic.

Apnea + Cadence Breathing Protocol Calculators