Effects of slow-paced breathing and humming breathing on heart rate variability and affect: a pilot investigation

This study aimed to evaluate the effects of slow-paced breathing (SPB) and humming breathing on heart rate variability (HRV) and affect.

The study included 16 healthy adults. HRV was measured for five min under three conditions: rest, SPB (5-second inhale, 5 s exhale; administered using the EliteHRV application), and humming breathing (Bhramari Pranayama). The Visual Analogue Scale (VAS) assessed anxiety, stress, relaxation, and confidence across baseline, rest, SPB, and humming breathing conditions.

Both SPB and humming breathing significantly increased HRV, with higher Standard Deviation of all Normal-to-Normal intervals (SDNN), Total Power (TP), and Low Frequency (LF) values than those in the rest condition. The VAS scores indicated higher relaxation levels during rest, SPB, and humming breathing than at baseline. No significant differences were observed between SPB and humming breathing in HRV or VAS measures.

These findings suggest that humming breathing is a viable alternative to SPB for enhancing HRV and autonomic regulation, without requiring specialized equipment or feedback.