The short answer
Breathing exercises have the best evidence for easing stress and anxiety, lowering blood pressure a little, raising heart rate variability and, with breathing muscle training, improving endurance. They may help sleep, low mood, panic and pain, but those studies are small. There is no good evidence that they ease hot flushes, boost immunity or detox your body.
On this page
How strong is the evidence for each benefit?
Breathing exercises are cheap, safe for most people and can genuinely help. But some claims made for them run far ahead of the research. Here is each common claim, graded using our four evidence grades. The grade tells you how sure we can be, not how big the effect is.
| Claim | Grade | Why |
|---|---|---|
| Raising heart rate variability | Strong | Slow breathing raises heart rate variability during and after practice in almost every study: 223 of them in one review. What that means for long-term health is less clear. |
| Easing stress and anxiety | Moderate | Reviews of randomised trials find small to moderate falls in stress and anxiety, though many trials were small or at risk of bias. |
| Lowering blood pressure | Moderate | Slow breathing lowered systolic blood pressure by about 5.6 mmHg across 17 studies, but the studies varied widely. |
| Sport and fitness | Moderate | Breathing muscle training improves endurance in reviews of dozens of trials. Other breathing methods have little evidence in sport. |
| Panic attacks | Weak | Slow breathing is standard advice, and breathing retraining makes panic treatment easier to stick with, but adds little to how well it works. |
| Sleep | Weak | One small study found slow breathing before bed improved sleep in people with insomnia. No trial has tested 4-7-8 breathing for sleep. |
| Low mood and depression | Weak | Trials suggest a small lift in mood, but most were small and at risk of bias. |
| Pain | Weak | Slow breathing lowered short-term pain in seven trials, but the evidence is very low certainty. |
| Menopause hot flushes | None | The largest trial found paced breathing worked no better than fast shallow breathing. Experts now recommend against it. |
| Boosting your immune system | None | Studies of the Wim Hof method found it damps down inflammation for a few hours, which is not the same thing. No trial shows fewer infections. |
| Detoxing or alkalising your body | None | Over-breathing briefly makes your blood more alkaline, which is what causes tingling and dizziness. It does not remove toxins. |
Why breathing changes how you feel
Breathing is the one part of your automatic nervous system you can easily control. When you breathe slowly, and especially when you make the out-breath longer than the in-breath, your heart rate swings up and down more with each breath and your body tends to shift towards a calmer state. Researchers think the vagus nerve, which links your brain with your heart, lungs and gut, carries much of this effect. See the vagus nerve.
The pace matters more than the depth. Most calming exercises slow you to around five to seven breaths a minute, well below the usual 12 to 20. Breathing fast and deep has the opposite effect: it blows off carbon dioxide and can leave you dizzy, tingly and more anxious, not less.
How big are the effects?
Mostly small to moderate. A fall of about 5 mmHg in blood pressure is worthwhile: in drug trials, a fall of that size cut the risk of heart attacks and strokes by about a tenth. A small to moderate fall in stress is similar to what many other self-help approaches achieve. But breathing exercises are not a cure. They work best as a daily habit alongside the treatment you already have.
What breathing exercises can’t do
They can’t replace your inhalers, blood pressure tablets or antidepressants. They don’t treat sleep apnoea, and they won’t cure long COVID or a breathing pattern disorder on their own, though a physiotherapist may use them as part of treatment. If a claim sounds too good to be true, such as curing disease, boosting immunity or detoxing, there is almost certainly no good evidence for it.
In this section
- Breathing exercises for stress and anxiety: what works
Which breathing exercises ease stress and anxiety, how to use them in the moment and every day, and what randomised trials show about how well they work.
Moderate - Breathing during a panic attack: what helps and what doesn't
How to breathe during a panic attack, why slow, gentle breathing helps, why not to use a paper bag, and what research shows about breathing retraining.
Weak - Breathing exercises for blood pressure: what the trials show
How much slow breathing and breathing muscle training lower blood pressure, how to do them, and how they fit with lifestyle changes and medicines.
Moderate - Breathing and heart rate variability (HRV): what it means
What heart rate variability is, why slow breathing raises it, what resonance breathing does, and what your HRV reading from a watch can and can't tell you.
Strong - Breathing exercises for sleep: do they help you fall asleep?
Which breathing exercises may help you fall asleep, what the small studies found, why there is no trial of 4-7-8 for sleep, and what to do about insomnia.
Weak - Breathing exercises for low mood and depression
Whether breathing exercises can lift low mood or help depression, what the trials show, and how they fit alongside talking therapy and other treatment.
Weak - Breathing exercises for sport and fitness: what helps
Which breathing methods can improve sport and fitness, what trials of breathing muscle training show, and why most breathing claims in sport lack evidence.
Moderate - Breathing exercises for pain: what the evidence shows
Whether slow breathing can ease short-term and long-term pain, what the trials found, how to use breathing when you are in pain, and when to see a doctor.
Weak - Breathing exercises for hot flushes: what the trials found
Paced breathing was once widely advised for menopause hot flushes. What the largest trial found, why experts now advise against it, and what helps.
None
Common questions
What are the proven benefits of breathing exercises?
The most reliable effects are on heart rate variability, which slow breathing raises in almost every study, and on stress and anxiety, which fall by a small to moderate amount in trials. Slow breathing also lowers blood pressure a little, by about 5 mmHg on average.
How long do breathing exercises take to work?
Some effects are immediate: a few minutes of slow breathing can make you feel calmer. Effects on blood pressure and long-term stress built up over weeks of daily practice in trials, usually 5 to 20 minutes a day for 4 to 12 weeks.
Can breathing exercises replace medication?
No. They can add to treatment for anxiety, high blood pressure, asthma or COPD, and sometimes help people need less reliever medicine, but they are not a substitute. Never stop or reduce a prescribed medicine without talking to your GP, nurse or pharmacist.
References
- Fincham GW et al. Effect of breathwork on stress and mental health: a meta-analysis of randomised-controlled trials. Scientific Reports, 2023.pubmed.ncbi.nlm.nih.gov
- Chaddha A et al. Device and non-device-guided slow breathing to reduce blood pressure: a systematic review and meta-analysis. Complementary Therapies in Medicine, 2019.pubmed.ncbi.nlm.nih.gov
- Laborde S et al. Effects of voluntary slow breathing on heart rate and heart rate variability: a systematic review and a meta-analysis. Neuroscience and Biobehavioral Reviews, 2022.pubmed.ncbi.nlm.nih.gov
- Illi SK et al. Effect of respiratory muscle training on exercise performance in healthy individuals: a systematic review and meta-analysis. Sports Medicine, 2012.pubmed.ncbi.nlm.nih.gov
- Zaccaro A et al. How breath-control can change your life: a systematic review on psycho-physiological correlates of slow breathing. Frontiers in Human Neuroscience, 2018.pubmed.ncbi.nlm.nih.gov
First published 4 November 2026. Next review due November 2027. Spotted an error? Tell us and we'll correct it. Read our editorial policy.