Assessment

CO₂ Tolerance

CO₂ tolerance reflects how well your body handles the urge to breathe — the key limit on breath control, composure under stress, and endurance. This test measures yours with a single slow exhale.

Breathe through your noseStay seated and still

How it works

  1. 1. Follow the orb for 5 calm warm-up breaths.
  2. 2. On breath 6, take one gentle inhale when prompted.
  3. 3. Exhale as slowly and softly as possible, then tap Stop when you need to inhale.

This is a baseline check, not a challenge. Stay seated, stop at the first clear need to inhale, and return to normal breathing if you feel dizzy or strained.