Box Breathing for Stress Regulation, Attention, and Performance: A Narrative Review

Box breathing is a systematic respiratory exercise with equal-duration phases of inhalation, breath-holding, exhalation, and a second breath-hold, typically four seconds per phase.This narrative review analyzes direct evidence on box breathing and distinguishes it from other controlled breathing techniques.The review used an updated PubMed search and cited additional studies, categorizing results by stress and emotional outcomes, attention and performance effects, and autonomic or recovery results.The review identified nine primary studies that specifically examined box, square, or tactical breathing.The findings suggest that box breathing may reduce state anxiety and physiological stress responses in various settings, including daily practice and real-world situations involving acute stress.However, studies reported inconsistent improvements in cognitive and task performance following box breathing.For instance, a pilot study reported fewer inhibitory control errors but longer reaction times following the breathing intervention.One randomized study on marksmanship showed improved first-shot accuracy, while another highlighted better task performance during prolonged exhalation than with tactical breathing.Physiological effects varied by context; one study reported increased high-frequency heart rate variability during recovery from maximal exertion, while another reported a higher post-exercise heart rate and perceived exertion with box breathing than with a six-breaths-per-minute method after intense interval exercise.The broader literature on slow breathing suggests improvements in vagally mediated HRV and stress regulation.However, these advantages may not extend to the equal-phase protocol, which includes two breath-holding phases.Overall, the evidence suggests that box breathing may serve as a potentially useful strategy for short-term stress management strategy for certain individuals, but it does not support consistent improvements in attention, cognitive performance, or athletic capabilities.