Acquire a core relaxation skill (and actually practice it until automatic)

SIT requires one somatic coping skill — diaphragmatic breathing or PMR — trained to automaticity before stress practice begins.

Why it works

Stress inoculation works by pairing acquired coping skills with progressively challenging stressors. The skills must be genuinely available — retrieval-ready — before they are tested under stress, otherwise the inoculation trial is simply a failed exposure. Diaphragmatic breathing activates the parasympathetic branch of the autonomic nervous system through the respiratory-cardiac interaction, providing a reliable physiological interrupt to the sympathetic stress response.

How to do it

1. Learn diaphragmatic breathing: inhale slowly into the belly for 4 counts, pause 1, exhale for 6–8 counts.
2. Practice daily for two weeks in non-stressful conditions until it requires no conscious monitoring.
3. Then practice during mild stress (a traffic jam, a deadline) to bridge from calm to stressed context.
4. Add progressive muscle relaxation (systematically tensing and releasing muscle groups) as a complement if breathing alone is insufficient.

Evidence

Diaphragmatic breathing and progressive muscle relaxation have consistent evidence for reducing physiological stress markers (cortisol, heart rate) and subjective anxiety across multiple populations in controlled studies. (rct)

Effect sizes vary considerably by population and application context; relaxation is most effective as a component of broader interventions rather than as a standalone treatment.

Sources

• Conrad & Roth (2007), muscle relaxation therapy for anxiety disorders: meta-analysis, Journal of Anxiety Disorders

Common mistake

Learning the breathing technique but not automating it before stress trials — then trying to use it under pressure for the first time, when cognitive load is highest and new skills are least accessible.