Body Oxygen Level Test — a breath-hold assessment measuring CO₂ tolerance (despite the "oxygen" in the name).
BOLT is the time between a normal exhale and the first definite urge to breathe, held with the mouth closed. It reflects chemoreceptor sensitivity to CO₂. Auralize uses BOLT to scale box-breathing interval and to gate the CO₂ Capacity Builder program.
See also
Learn · Assessments
The BOLT Test: What It Measures and How to Interpret It
BOLT stands for Body Oxygen Level Test — a misleading name, since it actually measures CO₂ tolerance. Here is what your BOLT score means and what to do with it.
Learn · Science
CO₂ Tolerance: The Real Limiter in Breathwork
The urge to breathe is driven by CO₂, not oxygen. Train that urge and every breathwork practice — plus a lot of your resting physiology — improves.
Learn · Compare
BOLT vs CO₂ Tolerance Test: What's the Difference?
Both test breath hold time after an exhale. The critical difference is when you stop the clock — first urge (BOLT) or first strain (CO₂ test). That changes what you are measuring.