box breathing for focus
calm alertness in 5 minutes

your prefrontal cortex underperforms when cortisol is elevated. box breathing (4-4-4-4) is the US Navy combat tactical breathing protocol — equal-ratio phases regulate autonomic arousal without inducing drowsiness. 16 seconds per cycle. the timer counts for you.

start box breathing

Protocol

01
inhale (4s)
breathe in slowly through the nose for 4 seconds. steady, controlled.
02
hold (4s)
hold the breath for 4 seconds. lungs full, body still.
03
exhale (4s)
exhale smoothly through the nose for 4 seconds. equal to the inhale.
04
hold (4s)
hold the breath out for 4 seconds before the next cycle. repeat for 5–10 cycles.

Mechanism

equal-ratio breathing regulates autonomic arousal without sedation. the balanced 1:1 inhale-to-exhale ratio calms the sympathetic nervous system while preserving alertness — unlike exhale-dominant patterns that induce drowsiness.

Ma et al., 2017, Frontiers in Psychology →

5 min/day of structured breathing reduced cortisol and improved affect more than mindfulness meditation in a Stanford RCT (n=108). cortisol reduction directly improves prefrontal cortex function.

Balban et al., 2023, Cell Reports Medicine →

slow-paced breathing at 6 breaths/min increases heart rate variability and baroreflex sensitivity, markers of autonomic flexibility linked to sustained attention.

Lehrer & Gevirtz, 2014, Applied Psychophysiology and Biofeedback →

FAQ

why do navy seals use box breathing?
box breathing is part of the US Navy's official combat tactical breathing program. the equal-ratio pattern (4-4-4-4) dampens the stress response while maintaining alertness — unlike exhale-dominant patterns that induce relaxation. it runs at ~4 breaths per minute, well below the threshold where autonomic calming begins.
does box breathing help with ADHD?
there is growing evidence that structured breathing improves autonomic regulation, which is linked to executive function. a 2025 meta-analysis (600+ adults across 10 studies) found significant symptom improvement, with the strongest effects on executive function specifically. box breathing's zero-friction format — no setup, no tutorial — is particularly well-suited for ADHD.
how long should I do box breathing?
5 minutes is the most studied duration. balban et al. (2023) used 5-minute daily sessions in their Stanford RCT. for pre-task focus, even 2 minutes (about 8 cycles) measurably lowers heart rate and cortisol.
what's the difference between box breathing and 4-7-8?
box breathing (4-4-4-4) is equal-ratio — it calms without sedating. 4-7-8 has an extended exhale that strongly activates the parasympathetic nervous system, making it better for sleep. use box breathing when you need to stay alert; use 4-7-8 when you want to wind down.