A few minutes of controlled breathing may blunt the body’s short-term reaction to a stressful speaking task, according to a small study published in Comprehensive Psychoneuroendocrinology and reported by PsyPost.
Researchers at Texas State University and the University of Toronto Mississauga randomly assigned 66 university students to normal breathing, box breathing (equal-length inhale, hold, exhale and hold) or prolonged exhalation (a short inhale followed by a slower exhale). All then gave a speech in a virtual version of the Trier Social Stress Test. The normal-breathing group showed rises in heart rate, self-reported anxiety and salivary alpha-amylase, a stress-related marker, while neither breathing group showed those spikes. Cognitive performance did not differ between groups.
The authors noted limits: the sample was small, young and healthy, the judges were pre-recorded, and heart rate variability was not measured during the breathing itself. The study tested short-term stress reactivity, not long-term health outcomes or treatment of any condition.