Key Takeaway
CO2 tolerance is trainable and improvements correlate with reduced dysfunctional breathing symptoms and better stress resilience.
Summary
This review examined the concept of CO2 tolerance and its implications for breathing training and health.
Key concepts:
- CO2 tolerance = threshold at which breathing urge occurs
- Lower tolerance = tendency toward hyperventilation
- Higher tolerance = more efficient breathing patterns
- Tolerance is modifiable through training
Health correlations:
- Low CO2 tolerance linked to anxiety, panic
- Associated with exercise intolerance
- Connected to sleep-disordered breathing
- Affects stress response
Training effects:
- Breath-hold practices increase tolerance
- Nasal breathing normalizes CO2 levels
- Reduced breathing volume improves tolerance
- Benefits seen within weeks
Clinical significance:
Provides theoretical foundation for using BOLT and similar tests to assess and track breathing health, supporting breathwork interventions.