Reading Scott Carney’s book ‘What Doesn’t Kill Us.’ Cold.
The initial test came from chapter “The Wedge.” First step was to take a baseline measurement for holding the breath. This turned out at 1 minute and 15 seconds, higher than the suggested range of 30 to 60 seconds without any training. Slight ego flare.
Next step was to take 30 fast breaths. The inhalation should take around a second and the exhalation should be allowed, not forced. Done, then followed by a large inhalation and hold. When the urge to exhale becomes feverish, you are supposed to clench your musculature and hold as long as you can.
Time crept by.
Exhalation at last: 2 minutes and 45 seconds of holding the breath.
This bears further investigation. But not while driving.