How to improve HRV with breathing

What is the best breathing exercise for HRV?

Slow, even breathing at about 6 breaths a minute, often called resonance or coherent breathing. Your heart speeds up a little as you breathe in and slows as you breathe out. At around 6 breaths a minute those swings are as large as they get for most adults, because your breathing and a blood-pressure reflex fall into step (Lehrer & Gevirtz 2014). Bigger swings mean higher HRV.

In a head-to-head lab test, 84 students tried box breathing, 4-7-8 and two versions of 6 breaths a minute. Breathing at 6 a minute raised HRV more than either named technique (Marchant et al. 2025).

How to improve HRV quickly

Start the player above. HRV rises during slow breathing almost at once, so if your watch or app shows a live reading, you’ll see it climb within a couple of minutes. That’s a real change, but it’s the in-session number.

Your resting HRV, the morning or overnight figure most wearables report, moves more slowly. It responds to how you’ve slept, what you drank, whether you’re ill, how hard you trained and how stressed you’ve been. Breathing helps with the last of those, and it may help you sleep. It can’t cancel out the rest.

Does breathing really increase HRV?

Yes, at least while you do it. A 2022 review of 223 studies found slow breathing raised heart rate variability during practice, straight after one session and after programmes lasting weeks (Laborde et al. 2022).

Lasting change is less certain. In a trial of 64 young adults, those who did 15 minutes of slow breathing each evening for 30 days showed more “rest” activity in their overnight HRV than those who spent the time on social media (Laborde et al. 2019). But in a trial of 108 adults practising 5 minutes a day for 28 days, resting HRV didn’t change in any group (Balban et al. 2023). Longer sessions may matter.

So: slow breathing raises HRV reliably in the moment. For your resting baseline, think weeks of 10 to 15 minutes a day, not one good session.

How well each breath is studied

• Coherent breathingWell studied
• Slow breathing (6-6)Some evidence

Every study on this page (8)

• Lehrer & Gevirtz, 2014: Heart rate swings most at around six breaths a minute; this review says a blood-pressure reflex is the likeliest reason.
• Marchant et al., 2025: In 84 students, six breaths a minute raised heart-rhythm signs of calm modestly more than box or 4-7-8 breathing; none changed mood.
• Laborde et al., 2022: Across 223 studies, slow breathing raised heart-rhythm signs of calm, during practice and after, though that alone doesn't prove a health benefit.
• Laborde et al., 2019: In 64 healthy young adults, a month of 15-minute evening slow-breathing sessions improved self-rated sleep more than time on social media.
• Balban et al., 2023: Five minutes a day of cyclic sighing lifted mood a little more than mindfulness meditation, in 108 adults.
• Meehan & Shaffer, 2024: In two small studies at six breaths a minute, breathing out longer than in made no difference to heart-rhythm measures.
• Lehrer et al., 2020: Across 58 trials, breathing guided by live heart-rhythm feedback brought modest benefits, most for anxiety, low mood and performance, least for sleep.
• Steffen et al., 2017: One 15-minute session at about six breaths a minute lifted mood and kept blood pressure lower under stress in 95 students.

What is HRV biofeedback?

It’s slow breathing with a live readout. A sensor tracks your heart, and a screen shows how much your heart rate is rising and falling as you breathe. You adjust your pace until the swings are biggest: that’s your personal resonance pace, usually between about 4.5 and 6.5 breaths a minute for adults (Meehan & Shaffer 2024).

It has a fair amount of research behind it. A review of 58 randomised studies found a small-to-moderate overall benefit, largest for anxiety, depression and performance (Lehrer et al. 2020). You don’t need the kit to start, though. Most people do well at 6 breaths a minute, and a plain pacer such as Breathform holds it steady without a sensor. If 5-5 feels quick, try 6 in and 6 out, which is 5 breaths a minute:

How do I see the effect on my watch or ring?

Two ways, and they tell you different things.

New to the numbers? What is HRV, and what’s a good HRV? explains them in plain words.

How long does it take to improve HRV?

Minutes for the in-session rise. For your resting HRV, one trial that found a change used 30 days of 15-minute evening sessions (Laborde et al. 2019). Even one session can help you under pressure: students who breathed at their resonance pace for 15 minutes before a stressful maths task felt more positive afterwards and had lower systolic blood pressure during it than students who sat quietly (Steffen et al. 2017).

Slow breathing is one part of the picture, alongside sleep, movement and less alcohol. For why it calms you as well as shifting a number, read how to calm your nervous system.

Questions people ask

Why is my HRV low?

Often for ordinary reasons: a short night, a drink the evening before, a cold coming on, a hard workout or a stressful week. HRV also falls with age, and some people simply run lower than others. A single low reading means little. A trend that drifts down over a couple of weeks is worth noticing, and asking what has changed.

Does box breathing improve HRV?

Less than slow, even breathing does. In a lab study of 84 college students, breathing at 6 breaths a minute raised heart rate variability more than box breathing or 4-7-8 (Marchant et al. 2025). Box breathing is still useful for steadying yourself before something. For HRV, a pace of about 5 seconds in and 5 out does more.

Can breathing too slowly be a problem?

It can make you light-headed if you breathe too deeply at the same time. In one lab study, breathing at 6 breaths a minute led to mild over-breathing. The fix is simple: keep each breath soft and quiet, not big. If you feel dizzy or tingly, take a few normal breaths and start again more gently.

What time of day should I measure HRV?

At the same time every day, in the same position. Many wearables use the night or the first minutes after waking, which is a good choice because nothing else is going on. Compare a week’s average with the week before rather than reacting to one morning’s number.