Short answer
To breathe when singing, take a low, easy breath that's comfortable rather than as big as possible, then let the air out steadily through the phrase. "Sing from your diaphragm" is a metaphor: the diaphragm is a breathing-in muscle, and researchers have mostly found it passive in speech (Sundberg, 1992). Breath control comes mainly from managing the out-breath with your rib and belly muscles.
What does "sing from your diaphragm" actually mean?
"Sing from your diaphragm" is shorthand for "breathe low and control the out-breath", not a literal instruction. You can't sing from your diaphragm, because the diaphragm's main job is breathing in.
The diaphragm is a dome-shaped muscle under your lungs. When you breathe in, it tightens and flattens, moving down towards your belly; when you breathe out, it relaxes and curves back up (Cleveland Clinic). Singing happens on the out-breath. In a review of breathing research, voice scientist Johan Sundberg notes that most researchers have found the diaphragm passive during speech, and that singers differ: some use it only when breathing in and to hold back pressure when their lungs are very full, while others keep it gently engaged through the whole phrase (Sundberg, 1992).
So why do teachers say it? Because a low breath, where your belly moves out as you breathe in, is a sign the diaphragm did its job. Sundberg points out that a belly moving outwards on the in-breath is a safe sign the diaphragm was used, while a belly pushing out during singing isn't necessarily a sign of anything (Sundberg, 1992). The phrase is trying to get you to stop gasping into your upper chest and to stay calm and steady while you sing.
What is breath support?
Breath support means keeping the air pressure under your vocal folds steady and right for each note, so the sound doesn't wobble, fade or get pushed. It's a skill of control, not strength.
That pressure does a lot of work. It's the main way you control loudness: more pressure, louder sound. In singing it also has to change with pitch, because higher notes need higher pressure than lower ones. Sundberg describes singers matching the pressure to every single note, and notes that getting it wrong shows up as singing off pitch (Sundberg, 1992). That may be one reason pitch can sag at the end of a long phrase. Why do I sing flat? covers that in more detail.
Where teachers disagree is how to teach it. Some ask you to keep your belly out while you sing; others ask you to draw it in. Sundberg reports that singers use both strategies, each with its own mechanical trade-off, and drily notes that some arguments for one method are taken more seriously than they deserve (Sundberg, 1992). If two teachers tell you opposite things, they may both be describing something that works for some singers.
Practise in short, calm sessions
A short voice check, then a daily plan of 3 to 15 minutes. Your voice stays on your phone.
Should my stomach go in or out when I sing?
Your belly usually moves out as you breathe in and then gradually in as you sing, and that's all a beginner needs to know. There's no single correct belly position that every good singer uses.
A small study measured the breathing of 7 professional classical singers and 4 untrained people. During singing, the singers' bellies accounted for about 35% of the change in lung volume, compared with about 14% for the untrained group, and the singers consistently drew their belly wall inwards just before they started to sing (Salomoni, van den Hoorn and Hodges, 2016). The study was small and only included classical singers, so treat it as a description of what some trained singers do, not a rule.
Singing teacher and breathing researcher Sally Collyer describes measurements of 10 highly trained female singers holding the same swelling-and-fading note: each was very consistent from one try to the next, but the ten of them started and ended the note at very different lung levels. She also notes that the same instruction has different effects on different singers (Collyer, NATS). The lesson for you: aim for a breath that's low, quiet and comfortable, and don't worry about copying an exact belly movement.
How do I know if I'm breathing low enough?
Put one hand on your upper chest and one on your belly, breathe in slowly, and notice which hand moves more. If the belly hand moves out first and your shoulders stay down, you're breathing low.
- Shoulders rising? That means the breath is going mainly into the top of your chest, usually in a quick gasp. It isn't dangerous, but a gasp is noisy and rushed. Try breathing in through a relaxed, slightly open mouth as if surprised, more slowly.
- Lying down helps. On your back with knees bent, a low breath tends to happen by itself. Notice how it feels, then try the same breath standing.
- No forcing. You don't need to push your belly out. Let it move because air is coming in.
How much air should I breathe in?
Take a comfortable breath, not the biggest one you can. Overfilling your lungs makes singing harder, not easier.
Lungs behave a bit like a stretched balloon. The fuller they are, the harder they push air back out. Collyer's handout explains that, on average, singers start phrases with about 70–80% of their vital capacity (the most air you can breathe out after a full breath in) and end them at about 30–50%. Above about 80%, the outward push rises quickly, like stretching a rubber band, so you have to work to hold the air back, especially on quiet notes. Very low lung volumes take extra effort too (Collyer, NATS).
Singing also uses more of your lungs than talking. When we speak, we generally use about the middle half of our available air, but singing often needs much more of it (Watson and Hixon, 1985, summarised in Sundberg, 1992). That's why singing feels like it needs a different kind of breath, even though it's the same lungs.
How do I stop running out of breath when singing?
Most people run out of breath because they let too much air out at the start of a phrase, sing phrases longer than they've planned for, or push volume, not because their lungs are too small.
For a sense of scale: the University of Sydney's voice lab notes that adults can typically hold a quiet "ah" for 15–20 seconds (Sydney Voice Lab). In a study of 69 healthy adults aged 65 and over, the average was about 22 seconds, with no significant difference between age groups (Maslan et al., 2011). Most phrases in a simple song are far shorter than that, so the problem is rarely capacity. It's how the air is spent.
What helps:
- Start the note gently. A breathy, sighing start lets air escape before the note has properly begun. Start cleanly and calmly.
- Plan the breath before you need it. Mark breath points in the song (see below). Breathe before you're empty.
- Don't push volume. Louder singing needs more breath pressure, which makes long phrases harder work (Sundberg, 1992).
- Slow down at first. Practise long phrases a little slower and on one vowel, then add the words.
- Check the key. High notes need more pressure, so a song that's too high eats your air. How to sing high notes without straining explains how to lower it.
If long notes wobble or shake, the cause can be running low on air or a tight throat. Breathe sooner, sing a little quieter, and use the free pitch checker to watch whether the note stays steady.
Breathing exercises for singing
These five exercises train a calm breath in and an even breath out. They're common studio exercises rather than research-tested ones, so use them as practice, not magic. A few minutes a day is plenty.
- Hand-on-belly breaths. One hand on your belly, breathe in slowly through your nose for a count of 4, out through your mouth for a count of 4. Five times. Just notice the movement.
- The long hiss. Breathe in comfortably, then hiss "sss" as evenly as you can, like a slow tyre leak. Time it, without straining at the end. The goal is a steady sound, not a record.
- 4 in, 8 out. Breathe in for 4 counts, then let it out on a gentle "fff" for 8. Once that's easy, try 10 or 12 counts out.
- Hum it, then sing it. Hum a comfortable note for as long as feels easy, then sing it on "ah" with the same steady air. Humming makes uneven air easier to hear, and humming exercises for singing has more ways to use it. Vocal warm-ups for beginners builds this into a 5-minute routine.
- Catch breaths. Sing a short phrase on "la", take a quick, quiet breath in about a second, and sing it again. Repeat four times. Songs rarely give you time for a slow breath.
Practise at a time you can be calm, not rushed. Singbud's daily plans run 3, 5, 10 or 15 minutes, and breathing fits easily into the short ones. Breath is one skill among several; how to improve your singing voice puts it alongside the others.
Where should I breathe in a song?
Breathe at the natural gaps: the ends of phrases and lines, before long notes, and before high or loud passages. Then mark them, so you breathe in the same places every time.
- Speak the words first. Read the lines aloud. Where you'd naturally pause or take a breath is usually a good place to breathe when singing.
- Mark a slash. Put a "/" at each breath point on your lyric sheet. Don't breathe in the middle of a word or a short phrase.
- Add an extra breath if you need it. Before a long note or a high phrase, a small extra breath is better than running dry. You may need more breaths than the original singer took. That's fine.
- Practise the breaths on purpose. Sing the song slowly on "la", breathing only at your marks. Then speed up.
Practising breathing through a familiar, slow, public-domain song such as Amazing Grace or Auld Lang Syne works well, because the phrases are regular and the tempo is gentle.
Should I breathe through my nose or mouth?
Use both: breathe through your mouth (or mouth and nose together) for the quick breaths inside a song, and through your nose when there's time, such as before you start or in long gaps.
Mouth breaths are quicker, which is what you need inside a song. Nose breathing is gentler on a dry voice, and that matters because a dry voice works harder. The background to a 2009 laboratory study on vocal fold dehydration notes that clinicians typically advise voice patients against mouth breathing, lists nasal breathing among ways to keep the voice hydrated, and cites human studies in which dehydration made voicing feel harder (Witt et al., 2009). The NIDCD also advises drinking plenty of water and practising good breathing technique when singing or talking (NIDCD).
Questions
What does sing from your diaphragm mean?
It's a teaching metaphor for breathing low and controlling the out-breath. The diaphragm is mainly a breathing-in muscle: it tightens as you inhale and relaxes as you exhale, and researchers have mostly found it passive in speech. When teachers say it, they usually mean take a calm, low breath and let the air out steadily.
How do I strengthen my diaphragm for singing?
For singing, coordination matters more than strength. You need a calm, low breath in and a steady, controlled breath out. Practise slow belly breaths, a long even hiss, and breathing in for 4 counts and out for 8. A few minutes a day, done calmly, is enough. You don't need weights or crunches.
How do I stop running out of breath when singing?
Start notes cleanly instead of breathily, plan and mark your breaths before you need them, avoid pushing volume, and practise long phrases slowly first. Take a comfortable breath rather than a huge one, since very full lungs push air out fast. If high phrases eat your air, the song may be too high, so try a lower key.
How long should I be able to hold a note?
As a rough guide, adults can typically hold a quiet "ah" for 15 to 20 seconds, according to the University of Sydney's voice lab. Most phrases in simple songs are much shorter, so you rarely need your maximum. If you run out sooner, work on a gentle start and a steady, even out-breath rather than bigger breaths.
Should I breathe through my nose or mouth when singing?
Both. Quick breaths inside a song usually go through the mouth, or mouth and nose together, because they're faster. When there's time, breathe through your nose, which is gentler on a dry voice. Clinicians often advise voice patients to avoid mouth breathing, because a dry voice has to work harder.
Sources
- Sundberg (1992). Breathing behavior during singing. STL-QPSR 33(1), 49–64, including Watson and Hixon (1985) on lung volumes in speech and singing. KTH Royal Institute of Technology (PDF).
- Collyer. Bringing breathing science into the voice studio (handout). NATS (PDF).
- Salomoni, van den Hoorn and Hodges (2016). Breathing and singing: objective characterization of breathing patterns in classical singers. PLoS One 11(5). PMC.
- Cleveland Clinic (2021). Diaphragm. my.clevelandclinic.org.
- Sydney Voice Lab, University of Sydney (2025). Acoustic analysis normative data reference sheet, citing Goy et al. (2013). sydney.edu.au (PDF).
- Maslan, Leng, Rees, Blalock and Butler (2011). Maximum phonation time in healthy older adults. Journal of Voice 25(6). PMC.
- Witt, Regner, Tao and colleagues (2009). The effect of dehydration on phonation threshold flow in excised canine larynges. Annals of Otology, Rhinology and Laryngology 118(2). PMC.
- National Institute on Deafness and Other Communication Disorders (updated 2025). Taking care of your voice. nidcd.nih.gov.
This article isn't medical advice. If you have a breathing condition, follow your doctor's advice. Last reviewed October 2026.