What the trial did

The 2023 Stanford trial asked 108 people to practice for 5 minutes a day for 28 days; the breathing groups logged about 6 minutes a day on average. The box breathing arm had 21 people. Participants sat in a chair or lay down, and logged each session in a daily survey. Box breathers' mood improved over the month, though not significantly more than in the mindfulness meditation group.1

The trial tested 5 minutes only. It didn't compare 1 minute with 5 or 10, so it can't say whether longer is better. In a small group, 5 minutes a day was enough to see a change, and positive mood rose with the number of days people practiced.1

What Divine recommends

Divine recommends at least 5 minutes for the full effect, and says even 5 minutes leaves him calm and alert. His own routine is one 10- to 20-minute session a day, plus 1- or 2-minute "spot drills" when the chance comes up: in line, in traffic, before a workout.2

That is one practitioner's routine, and no study has tested it.

What other guidance says

A 2018 review of 15 slow-breathing studies found session lengths from about 1 minute to 30, many of them 5 to 15 minutes. The studies were too different to pool, so the review can't say which length works best.3

The NHS suggests at least 5 minutes of its breathing exercise, as part of your daily routine.4 Student Minds, a UK charity, suggests 5 to 10 minutes or longer for 7-11 breathing.5

Why longer isn't automatically better

Box breathing is slower than normal breathing, and some people feel a little dizzy when they start, because they are breathing more deeply than usual. An NHS trust's staff leaflet suggests repeating the box up to 4 times at first, and sitting or lying down to practice until you are used to it.6

Keep each breath at a comfortable size as it slows. A longer session at a strained pace is harder to keep up than a short one done gently.

The research can't settle the question either way. The Stanford trial ran for 4 weeks with no follow-up, and its authors call it exploratory, so it says nothing about what months of practice, or longer sessions, would add.1

How to build up

Week 1: 1 minute, once a day. Week 2: 3 minutes. Week 3: 5 minutes. If you miss a day, start again at the length you can do without thinking about the clock.

Use the session length control on the timer above: 1, 3, 5, 10 minutes or open-ended. A 3-minute session runs for 3 minutes and 12 seconds, because the timer finishes the cycle it is in rather than cutting a breath short.

If 4 seconds is a strain, start at 3-3-3-3 on the custom timer. In the Stanford trial, box counts ranged from 3 or 4 seconds up to 8 to 10, set for each person by a breath test, and people were told to shorten them if they had to strain.1 Once 5 minutes at 4 seconds is comfortable, Deep Box (6-6-6-6) is the slower version.

Twice a day is fine if it suits you. The trial asked for once a day.1

Every day, or most days

The trial's result came from a month of daily practice, and the NHS suggests making breathing part of your daily routine.1,4 A short session on a busy day keeps the habit going.

If you want a reminder, the app can send a daily one and keep a streak. The web timer has no account and no reminder; it is there when you open it.

Questions

Is 10 minutes of box breathing better than 5?

No study has shown that. The trial tested 5 minutes a day.1 Divine's own daily session is 10 to 20 minutes;2 10 is fine if it is comfortable, but it is not required.

Can I split it into 2 shorter sessions?

Yes. Divine's routine is one longer session plus 1- or 2-minute drills during the day.2 If 5 minutes feels long, 2 short sessions are a reasonable start.

Is 1 minute of box breathing enough?

For a short break, Divine uses 1- or 2-minute drills.2 No study has tested 1 minute on its own; the Stanford trial used 5.1

How soon will I notice anything?

In the Stanford trial, people rated their mood and anxiety right before and right after each 5-minute session. On average across the breathing groups, positive mood rose and anxiety fell after a session.1

What time of day is best?

The Stanford trial didn't set one.1 Divine practices in the morning and before a workout, then does short drills during the day.2 Pick a time you can keep.

How many cycles is 5 minutes?

At 4-4-4-4, one cycle is 16 seconds, so 5 minutes is about 19 cycles. The timer's 5-minute session runs 5:04 and completes 19 cycles.

How long is 1 minute of box breathing?

It's 4 cycles. The timer's 1-minute session runs 1:04, because it finishes the fourth cycle rather than stopping at 60 seconds.

Should I do box breathing before bed?

You can. Divine describes 4-4-4-4 as neutral: it won't make you sleepy, and it leaves him alert.2 For bedtime, 4-7-8 has a longer exhale and is taught for winding down,7 and a 2026 review found that slow breathing before bed improved self-reported sleep in 7 of 9 studies.8

Related timers

This guide isn’t medical advice.

Sources

  1. Balban, M. Y., Neri, E., Kogon, M. M., et al. (2023). Brief structured respiration practices enhance mood and reduce physiological arousal. Cell Reports Medicine, 4(1), 100895.The 5-minute daily dose, how the box counts were set, and the trial's design and limits
  2. Divine, M. (2016). A Navy SEAL breathing technique to stay calm and focused. Time.Divine's advice on session length, spot drills and the neutral effect of 4-4-4-4
  3. Zaccaro, A., Piarulli, A., Laurino, M., et al. (2018). How breath-control can change your life: a systematic review on psycho-physiological correlates of slow breathing. Frontiers in Human Neuroscience, 12, 353.Session lengths in slow-breathing studies and why they can't be pooled
  4. NHS. Breathing exercises for stress. Reviewed 12 June 2026.NHS advice to practice for at least 5 minutes, as a daily routine
  5. Student Minds. 7-11 breathing exercise. Published 1 July 2024.5 to 10 minutes for 7-11 breathing
  6. Sherwood Forest Hospitals NHS Foundation Trust. Breathing exercises (staff wellbeing leaflet).Dizziness when starting, repeating the box up to 4 times, and sitting or lying down
  7. Weil, A. The 4-7-8 Breath: health benefits and demonstration. DrWeil.com.4-7-8 for winding down
  8. Eide, E. M., et al. (2026). Slow breathing techniques before bedtime and the effects on sleep: a systematic review. Sleep Medicine Reviews, 102284.The review of slow breathing before bedtime