Theory 46/Biology & physiology/Diving reflex
Diving Is Bradycardia Against Resistance
The claim
Dive duration is set by the ratio of bradycardia magnitude to peripheral resistance, so the reflex extends breath-hold only if both change together.
01Mechanism
Slowing the heart saves oxygen while vasoconstriction redirects it to the brain.
02Prediction
Duration should track the ratio.
03Refutation
Duration tracking heart rate alone would remove redistribution.