Box breathing (4 seconds in, hold, out, hold) can help reduce felt pain for people with chronic pain — but probably not because it 'calms the vagus nerve,' more because it redirects attention and lowers overall arousal.

noli's read

Several experimental studies confirm that slow, deep breathing reduces perceived pain intensity from a controlled stimulus (heat, visceral pain) compared to breathing at a normal rate. But when researchers specifically tested the mechanism invoked here — that slow breathing reduces pain because it stimulates the vagus nerve or baroreceptors — the results don't confirm it: a study by Gholamrezaei et al. (Psychophysiology, 2021) explicitly concludes that 'these findings do not support the role of baroreceptor stimulation or vagal modulation' in the hypoalgesic effects of slow deep breathing, despite a real increase in heart-rate variability. Other work (Busch et al. 2012) shows only the 'relaxing' version of slow breathing reduces pain — not a version requiring concentration — pointing toward a more attentional/psychological mechanism than a purely autonomic-nervous one. A 2025 narrative review on box breathing specifically for chronic pain concludes dedicated evidence is sparse and mostly extrapolated from the broader slow-breathing and mindfulness literature. Verdict: mixed — the pain-relief effect of slow breathing is real and replicated, but the 'vagus nerve calming guarding muscles' explanation isn't what the studies that tried to isolate it actually confirm.

the sources

1. 1Zaccaro A et al. 2018