Biology of Business

Breath-holding and its breakpoint

Michael J. Parkes

Experimental Physiology (2006)

TL;DR

You cannot breath-hold to unconsciousness—involuntary systems override voluntary control to prevent fatal self-harm.

By Alex Denne

Research demonstrating limits of voluntary override in hybrid respiratory control - chemoreceptor feedback eventually forces involuntary breathing, illustrating hierarchical priority in hybrid systems.

Key Findings from Parkes (2006)

  • Normal subjects cannot breath-hold to unconsciousness despite voluntary effort
  • Central respiratory rhythm continues during breath-holding—only output is suppressed
  • PaCO2 at breakpoint is not constant across conditions or individuals
  • Bilateral phrenic/vagus nerve paralysis prolongs breath-hold duration
  • Diaphragm muscle chemoreceptors may contribute more than blood gas sensors
  • Highly cited review (181+ citations) in Experimental Physiology vol. 91, pages 1-15

Related Mechanisms for Breath-holding and its breakpoint