Long Exhale for Sleep

Acute effects of the 4-4-8 breathing technique on arterial stiffness in healthy young men

This study investigated the acute effects of the 4-4-8 breathing technique (4 seconds inhalation, 4 seconds pause, 8 seconds exhalation through the nose, 12 consecutive breaths over approximately 5 minutes) on arterial stiffness and autonomic function in 15 healthy young men (age 20 ± 0 years) using a randomized controlled crossover design with a control condition. Brachial-ankle pulse wave velocity (baPWV, reflecting systemic arterial stiffness) and brachial systolic blood pressure significantly decreased 30 minutes after the breathing compared to baseline (p < 0.05), while carotid-femoral PWV remained unchanged. Heart rate variability showed increased high-frequency (HF) power (p < 0.05) and decreased low-frequency (LF) power (p < 0.05), indicating enhanced parasympathetic activity and reduced sympathetic activity. No changes occurred in the control condition. The findings suggest slow breathing techniques like 4-4-8 modulate autonomic function and improve arterial stiffness in healthy young adults. Still You uses the no-hold 4-8 variant of this extended-exhale approach: it keeps the longer-exhale mechanism behind the parasympathetic shift while removing the breath hold, which makes the practice gentler close to sleep.