CO2 Tolerance Test for Breath Control

How to Perform the Test

1. Sit comfortably and relax for a minute. Breathe normally.
2. Take 3-4 calm, normal breaths.
3. After the final normal exhale, start the timer and hold your breath. **Do not inhale first.**
4. Stop the timer as soon as you feel the **first definitive urge** to breathe. This is not a test of holding your breath as long as possible.