Paced Breathing With a Prolonged Inspiratory Period Increases Sympathetic Activity: A Heart and Brain Analysis

Abstract

Paced breathing exercises with prolonged exhalation have been commonly used to reduce stress and anxiety by stimulating parasympathetic activity. However, increasing sympathetic activity may also provide benefits such as increased alertness and energy levels. In this work, we investigate the physiological impact of an 80-second breathing exercise with a prolonged inspiratory period of 6 seconds followed by 2 seconds of exhalation on the sympathetic system. We collected raw two-channel prefrontal electroencephalography and photoplethysmography signals of 19 subjects using EMOTAIs headband while performing the proposed exercise every workday for 2 weeks straight. Physiological metrics such as heart rate, heart rate variability, and absolute power of the brain waves were extracted before and during the exercise to measure its effectiveness. A marked increase in beta wave power was observed, along with a significant increase in both heart rate and heart rate variability. The cardiovascular results indicate that the proposed exercise effectively raised sympathetic activity. Simultaneously, the observed neural activity is consistent with that seen during focused attention and heightened mental processing.