. Author manuscript; available in PMC: 2022 Jul 24.

Published in final edited form as: Clin Psychol Rev. 2021 Jan 24;84:101980. doi: 10.1016/j.cpr.2021.101980

Table 2.

Overview of Respiratory Interventions

Types of Respiratory Intervention	Description
Diaphragmatic Breathing	Use of the diaphragm muscle to move air.
Controlled or Paced Breathing	Breathing at a given respiratory frequency (i.e., pace).
Breathing Retraining	Induction of hyperventilation, which is then contrasted with diaphragmatic breathing, to promote the practice of diaphragmatic breathing.
Heart Rate Variability Biofeedback	Breathing at objectively measured individual’s resonance frequency aiming to increase their heart rate variability. Feedback of physiological parameters is provided in real time to promote accuracy.
PaCO₂ Biofeedback	Breathing that targets a specific PaCO₂ level, approximated via end-tidal (i.e., expired) CO₂, to optimize gas exchange. Feedback of relevant physiological parameters is provided in real time to promote accuracy.