Breath in the classics: tuna, fuqi, lianqi and embryonic breathing

Author: Raymond Hackland · Last reviewed: 18 October 2026 · Reading time: about 10 minutes

In short

• What this is: Chinese texts on nourishing life use several names for breath practice: tuna (breathing out the old, in the new), xingqi (circulating qi), fuqi (ingesting qi), lianqi (refining qi) and taixi (embryonic breathing). This article explains what each one means in the sources, and where Liu Zi Jue’s “one way in, six ways out” fits among them. It is the second article of our neigong series.
• What the evidence says: The terms and methods are well documented in surviving texts from the 4th century BCE onwards. Their promises, such as long life or living without grain, are traditional beliefs. A separate box summarises what modern physiology says about slow and nasal breathing.
• What it means for your practice: The classics describe many breath methods, including long breath-holds. Liu Zi Jue comes from the gentlest strand: in through the nose, a long, soft out-breath through the mouth. Raymond’s practice keeps to that strand, with no breath holds and no fast breathing.

What tradition says

Label for this section: Tradition only (documented history), unless marked otherwise.

One word, two meanings. The character 气 (qì) means both the air we breathe and the subtler “qi” of tradition. The texts below move freely between the two, so a translator always has to choose. When they speak of “taking in qi”, they may mean an ordinary in-breath, something more refined, or both.

Breathing deep: the Zhuangzi. One of the oldest remarks on breath is in chapter 6 of the Zhuangzi, one of the “Inner Chapters” associated with Zhuangzi’s own time, the late 4th century BCE [1, 3]: “The true people of old … breathed deep, deep. The true person breathes from the heels; ordinary people breathe from the throat” (其息深深。眞人之息以踵，衆人之息以喉) [1]. It is a picture, not a technique: calm, deep breathing as a sign of a settled person.

Tuna (吐纳, traditional 吐納, tǔnà): out with the old, in with the new. The word comes from chapter 15 of the Zhuangzi, written more than 2,000 years ago, where “blowing and puffing (chui xu, 吹呴), breathing out and breathing in, expelling the old and taking in the new” (吐故納新, tǔ gù nà xīn) are named as the pursuits of daoyin practitioners, which the chapter views with some distance [2]. Our previous article in this series, “Daoyin: from the Mawangdui chart to modern Qigong“, looks at that passage in detail. A much later anthology, the Yangxing yanming lu (養性延命錄), first recorded between the 6th and 8th centuries, makes the method concrete. It quotes a master Liu Jun’an (刘君安), possibly the Han-dynasty adept Liu Gen, whose courtesy name was Jun’an [20]: “Take in the living, spit out the dead, and you can live long; that means breathing in through the nose is the living, breathing out through the mouth is the dead” (食生吐死，可以長存，謂鼻納氣為生，口吐氣為死也) [4]. It continues: anyone who cannot yet ingest qi should practise from morning to evening, “slowly and gently, always breathing in through the nose and out through the mouth: this is what is called expelling the old and taking in the new” (常令鼻納口吐，所謂吐故納新也) [4]. A modern dictionary gives the same picture: tuna is a Daoist practice of breathing out stale air through the mouth and breathing in fresh air through the nose [5].

Xingqi (行气, traditional 行氣, xíngqì): circulating qi. Xingqi means moving or guiding qi through the body. Its oldest-known witness is a small twelve-sided jade object now in the Tianjin Museum, dated by the museum to the Warring States period (475–221 BCE) and usually called the “jade pendant inscription on circulating qi” (行氣玉佩銘). It was not excavated under controlled conditions: it comes from a private collection [6], rubbings of its twelve faces were published in the first half of the 20th century, and the object itself was lost for a time before it resurfaced [21]. Donald Harper, a specialist in early Chinese medical manuscripts, dates it cautiously to the late Warring States, perhaps the late 4th or early 3rd century BCE [21]. The museum describes it as the ornament of a staff head (others consider its original function uncertain [21]) and gives the reading by the scholar Guo Moruo: “Circulating qi: when deep, it gathers; when it gathers, it extends; when it extends, it descends; when it descends, it settles; when it settles, it becomes firm; when firm, it sprouts; when it sprouts, it grows; when it grows, it returns; when it returns, it reaches heaven … Following this, one lives; going against it, one dies” [6]. Following Guo, the museum reads it as one full breath: the in-breath travels down to the lower belly, the out-breath rises back to the crown of the head [6]. Many scholars have interpreted the inscription, and readings differ [6, 21]. Harper, following another transcription, begins “Swallow, then it travels; traveling, it extends; extending, it descends…”, and he sees the same pattern of qi moving down and then returning upwards [21]. We rely here on these published readings, not on the object itself.

Later texts use xingqi as a general heading for breath methods. Ge Hong (283–343), in the Baopuzi (抱朴子), says that “although we speak of circulating qi, there are several methods of circulating qi”, and that their essence is embryonic breathing [7]. The Yangxing yanming lu gives the basic rule: “When circulating qi, breathe in through the nose and out through the mouth, gently and drawn out; this is called the long breath” [4].

Fuqi (服气, traditional 服氣, fúqì): ingesting qi. Fu means to take, as one takes a medicine. Fuqi, also shiqi (食气, “eating qi”), regards breath as nourishment. The Mawangdui manuscript Quegu shiqi (却谷食气, “Abstaining from grain and eating qi”), from a tomb sealed in 168 BCE, already sets eating qi against eating grain [8]. The Tang Daoist master Sima Chengzhen’s Fuqi jingyi lun (服氣精義論, “On the essential meaning of ingesting qi”) quotes a saying attributed to the Yellow Emperor: “those who eat grain are clever but die young; those who eat qi are spirit-like and long-lived” (食穀者知而夭，食氣者神而壽) [9]. His method is a demanding regimen: preparation with medicines and diet, a hundred days of purification, a gradual reduction of food, and then, in a quiet room facing the morning sun, breath drawn in gently through the nose and swallowed (咽) several times, held, and imagined spreading through the shoulders into the arms [9]. The text itself warns that in the first weeks of ingesting qi and avoiding grain, practitioners become weak, sallow, dizzy and thin [9]. The chapter of the Yangxing yanming lu that first records the six sounds is itself titled “Ingesting qi to treat illness” (服氣療病篇) [4]. A dictionary simply calls fuqi a Daoist method of self-cultivation [5].

Lianqi (炼气, traditional 鍊氣 or 煉氣, liànqì): refining qi. Lianqi is the loosest of these terms. A modern dictionary defines it as the method by which practitioners of the Way cultivate tuna in search of long life [5]. That is a modern definition, not a classical one, and it overlaps with everything above. We did not find a single classical passage that defines it. In inner alchemy (neidan), “refining” becomes the name for stages of practice that work on essence, qi and spirit; we come back to that in the series article “Jing, qi and shen: the three treasures of inner alchemy”.

Taixi (胎息, tāixī): embryonic breathing. For Ge Hong, embryonic breathing is the goal of all breath work: “Those who attain embryonic breathing can breathe without using nose or mouth, as if in the womb; then the Way is complete” (得胎息者，能不以鼻口噓吸，如在胞胎之中，則道成矣) [7]. The path there, as he describes it, is long breath retention. We summarise it here as history, not as instructions to follow. In his account, a beginner draws qi in through the nose, closes it off and counts silently to 120 before breathing it out gently through the mouth. In and out, the practitioner should “not hear the sound of the qi going in and out with one’s own ears”, should let more go in than out, and checks with a goose feather on nose and mouth that it does not move on the out-breath. The count is raised gradually until, “after a long time, one can reach a thousand” [7]. Raymond’s practice has no breath holds. Holding the breath is not suitable for everyone; our article on who should be careful with breathing practices explains why.

He adds that his great-uncle, the immortal Ge Xuan (traditionally 164–244), whom he calls the “Transcendent Duke” (仙公) [7, 22], could stay “at the bottom of a deep pool” for about a day “because he could close off his qi and breathe like an embryo” [7]. That is a hagiographic story, not a report anyone could check. The Baopuzi also lists a Taixi jing (胎息經, “Scripture of embryonic breathing”) among the books its author knew [10]; whether that lost work is related to the short scripture of the same name that survives is not known.

The surviving Gaoshang yuhuang taixi jing (高上玉皇胎息經) in the Daoist Canon is only 88 characters long. Its author and date are unknown: a Daoist reference database places it, tentatively, in the Tang dynasty (618–907) [23], and it existed by the first half of the eleventh century at the latest, when Zhang Junfang included it in his Daoist anthology Yunji qiqian [11]. It turns the idea inward: “The embryo forms within hidden qi; qi breathes within the embryo… When the spirit moves, qi moves; when the spirit rests, qi rests… If the mind does not stir, with no coming and going, no going out and in, of itself it always remains” [12]. A commentary attributed to “Master Huanzhen” places this “sea of qi” three cun below the navel and calls it the lower dantian [12]. Here embryonic breathing is less about holding the breath than about a stillness in which breath becomes so quiet it seems to stop. The two views coexist in the literature.

Breath retention in the texts. Label: Tradition only (documented history); not a recommendation. Closing off the breath (闭气, bìqì) is common in these sources. The Yangxing yanming lu, in the same chapter as the six sounds and just after quoting a “Scripture on ingesting qi” (服氣經), describes lying flat and then “closing off the qi and not breathing, counting to 200 in the mind, then breathing it out through the mouth”, increasing day by day [4]. It also quotes Pengzu, the legendary long-lived man, on “always closing off the qi and taking in the breath” (常閉氣納息) [4]. We report these methods because they are part of the history. They are not part of Raymond’s practice, and we do not suggest trying them (see below).

Where “one way in, six ways out” fits

Label for this section: Tradition only (documented history).

Liu Zi Jue’s formula sits inside this literature. The Yangxing yanming lu writes:

“When circulating qi, breathe in through the nose and out through the mouth, gently and drawn out; this is called the long breath. There is one way of taking in qi and six ways of letting it out. The one way in is the in-breath; the six ways out are chui, hu, xi, he, xu and si, all of them out-breaths” (納氣有一，吐氣有六。納氣一者，謂吸也；吐氣有六者，謂吹、呼、唏、呵、噓、呬，皆出氣也) [4].

A note on the characters: the Daoist Canon text writes xi as 唏; the standard form today writes 嘻. (Some online editions also write 內 for 納, “to take in”.) Placed among the terms above, the six-sound method is a form of tuna (nose in, mouth out), presented under the heading of xingqi and fuqi, and it shares its chapter with breath-retention exercises [4]. What makes it distinctive is that the out-breath, not the hold, carries the method. Later tradition moved it further in a quiet direction. A Song-dynasty text, Zou Pu’an’s Taishang yuzhou liuzi qijue (太上玉軸六字氣訣), preserved in a Yuan-dynasty compilation and quoted by the Chinese Health Qigong Association, asks that while reciting each sound “the ears must not hear” it, because hearing it means the breath is coarse; the in-breath, too, should be inaudible [24, 13]. That is an echo of Ge Hong’s instruction not to hear one’s own breath [7]. The Association sums up the historical sources as describing the six-sound breathing as “in through the nose, out through the mouth, even, fine, soft and long” [13]. Its 2003 standard form lets beginners voice the sounds and aims overall at breathing out without sound [14].

Box: what physiology says about slow and nasal breathing

Label for this box: Well studied (slow breathing and heart rate variability) · Early evidence (longer out-breaths; nasal nitric oxide). This box describes measurable physiology, not health effects.

• Slow breathing: well studied. A 2022 meta-analysis of 223 studies found that slowing the breath, often to about six breaths a minute, increases the part of heart rate variability linked to the vagus nerve, during practice and afterwards [15]. Our article on slow breathing and heart rate variability explains how.
• A longer out-breath: early evidence. Some small lab studies found that, at six breaths a minute, an out-breath longer than the in-breath produced somewhat more of this effect [16, 17]; other studies found no difference. We summarise the mixed picture in long exhalation and the vagus nerve.
• Breathing through the nose: early evidence. The sinuses produce nitric oxide, and nasal breathing carries some of it towards the lungs [18]; humming raises nasal nitric oxide sharply for a short time [19]. These are small laboratory findings, and health benefits have not been established; see humming and nitric oxide in the nose.
• Holding the breath and breathing fast are different. They change blood gases and blood pressure in ways that are not suitable for everyone. Our article on who should be careful with breathing practices explains who should take extra care.

None of these studies tested Liu Zi Jue or the classical methods described above.

Where popular claims go beyond the evidence

Label for this section: Speculative.

• “Embryonic breathing means you can stop breathing.” Ge Hong’s story of a man staying a day underwater is a legend [7]. Long breath-holds can make people faint, and fainting in or near water can be fatal.
• “Ingesting qi lets you live without food.” Grain avoidance and “eating qi” are well documented as religious practices [8, 9], and Sima Chengzhen himself describes weakness and weight loss in the first weeks [9]; the claim that breath can replace food is not supported, and fasting is not without risk.
• “The jade inscription proves the microcosmic orbit is 2,500 years old.” The inscription describes breath going down and coming back up [6]. Readings of it differ, and linking it to later inner-alchemy systems is an interpretation.
• “Holding your breath longer is more advanced.” In the texts, retention was one path among several; the Taixi jing already speaks of stillness rather than effort [12]. In modern practice, no breath-hold length is a measure of skill.

How this relates to the Six Healing Sounds, Qigong and neigong

Label for this section: Tradition only (documented history), with Raymond’s teaching marked as his own.

Liu Zi Jue is one of the most lasting results of this breath literature. It takes the oldest principle, tuna, “out with the old, in with the new” [2, 4], and gives the out-breath six shapes. In the Qigong of today it survives as a standard Health Qigong form [14]; in neigong it belongs to the “internal” work of breath and attention described in our series introduction, “What is neigong? An introduction“. You can read more about its development in the history of Liu Zi Jue. The more demanding methods of the same texts, long retention, swallowing the breath and grain avoidance, belong to the religious history of Daoism and are best understood in that context.

How I share the sounds. In my practice you breathe in quietly through the nose and breathe each of the six sounds out through the mouth. The sounds are “voiced through the breath”, not sung. I share xi as the sound of the triple burner and of the whole body, as the 2003 standard form does [14]. Over time my sessions work towards a silent exhalation, as the 2003 standard form also aims to do [14]. The breathing stays slow and controlled throughout: no breath holds and no fast breathing. That is a deliberate choice. The classical retention methods described above are history, not part of the practice. If you have a health condition, please read who should be careful with breathing practices first.

Resonance Heritage Qi is a personal, music-assisted practice inspired by Liu Zi Jue: connected to it, not a replacement for the traditional form or for study with a teacher of that tradition.

Where this series goes next

Next in our neigong series: “The three dantians: what the classical texts say”, on the “elixir fields” where many of these texts direct the breath.

Sources

1. Zhuangzi 莊子, chapter 6, 大宗師 (Da zongshi). Chinese text, Wikisource edition, accessed 18 October 2026. https://zh.wikisource.org/wiki/莊子/大宗師
2. Zhuangzi 莊子, chapter 15, 刻意 (Keyi). Chinese text, Wikisource edition, accessed 18 October 2026. https://zh.wikisource.org/wiki/莊子/刻意
3. Hansen C. Zhuangzi. Stanford Encyclopedia of Philosophy, first published 17 December 2014, substantive revision 24 March 2024. https://plato.stanford.edu/entries/zhuangzi/
4. Tao Hongjing (attributed). 養性延命錄 Yangxing yanming lu, juan 2, chapter 4 (服氣療病篇). Daoist Canon (Zhengtong Daozang) text, digital edition: Kanripo, KR5c0235, accessed 18 October 2026. https://www.kanripo.org/text/KR5c0235/002 ; punctuated Wikisource edition, which reads 劉安 for 劉君安 and 內 for 納: https://zh.wikisource.org/wiki/養性延命錄
5. Ministry of Education (Taiwan). 重編國語辭典修訂本 (Revised Mandarin Chinese Dictionary), entries 吐納, 服氣, 鍊氣, 胎息 and 閉氣, read via the open edition at moedict.tw, accessed 18 October 2026. https://www.moedict.tw/
6. Tianjin Museum 天津博物馆. 战国 青玉”行气铭”文饰 (Warring States green jade ornament with inscription on the circulation of qi). Collection page, accessed 18 October 2026. https://www.tjbwg.cn/cn/collectionInfo.aspx?Id=2358
7. Ge Hong 葛洪. 抱朴子內篇 Baopuzi neipian, juan 8, 釋滯 (Shizhi). Chinese text, Wikisource edition, accessed 18 October 2026. https://zh.wikisource.org/wiki/抱朴子/卷08
8. 馬王堆漢墓簡帛 Mawangdui Han tomb manuscripts: 去穀食氣 (Quegu shiqi, usually written 却谷食气). Chinese text, Wikisource edition, accessed 18 October 2026. https://zh.wikisource.org/wiki/馬王堆簡帛/去穀食氣
9. Sima Chengzhen 司馬承禎. 服氣精義論 Fuqi jingyi lun. Chinese text, Wikisource edition (Yunji qiqian, juan 57), accessed 18 October 2026. https://zh.wikisource.org/wiki/服氣精義論
10. Ge Hong 葛洪. 抱朴子內篇 Baopuzi neipian, juan 19, 遐覽 (Xialan). Chinese text, Wikisource edition, accessed 18 October 2026. https://zh.wikisource.org/wiki/抱朴子/卷19
11. Zhang Junfang 張君房 (comp.). 雲笈七籤 Yunji qiqian, juan 60 (胎息經, with commentary), and Zhang Junfang’s preface. Chinese text, Wikisource editions, accessed 22 October 2026. https://zh.wikisource.org/wiki/雲笈七籤/60 ; https://zh.wikisource.org/wiki/雲笈七籤/序
12. 高上玉皇胎息經 Gaoshang yuhuang taixi jing, and 胎息經註 Taixi jing zhu (commentary attributed to Huanzhen xiansheng 幻真先生). Chinese texts, Wikisource editions (Zhengtong Daozang), accessed 18 October 2026. https://zh.wikisource.org/wiki/高上玉皇胎息經 · https://zh.wikisource.org/wiki/胎息經註
13. Chinese Health Qigong Association, 2016. 健身气功·六字诀功法源流 (Health Qigong Liu Zi Jue: origins of the method). Health Qigong Management Center, General Administration of Sport of China, published 20 December 2016. https://www.sport.gov.cn/qgzx/n5407/c781291/content.html
14. Zhang Mingliang, Ma Ling, 2016. 健身气功·六字诀养生撷萃 (Health Qigong Liu Zi Jue: essentials for nourishing life). Health Qigong Management Center, published 11 November 2016. https://www.sport.gov.cn/qgzx/n5407/c775164/content.html
15. Laborde S, Allen MS, Borges U, Dosseville F, Hosang TJ, Iskra M, Mosley E, Salvotti C, Spolverato L, Zammit N, Javelle F, 2022. Effects of voluntary slow breathing on heart rate and heart rate variability: a systematic review and a meta-analysis. Neuroscience & Biobehavioral Reviews 138:104711. https://doi.org/10.1016/j.neubiorev.2022.104711
16. Van Diest I, Verstappen K, Aubert AE, Widjaja D, Vansteenwegen D, Vlemincx E, 2014. Inhalation/exhalation ratio modulates the effect of slow breathing on heart rate variability and relaxation. Applied Psychophysiology and Biofeedback 39(3–4):171–180. https://doi.org/10.1007/s10484-014-9253-x
17. Laborde S, Iskra M, Zammit N, Borges U, You M, Sevoz-Couche C, Dosseville F, 2021. Slow-paced breathing: influence of inhalation/exhalation ratio and of respiratory pauses on cardiac vagal activity. Sustainability 13(14):7775. https://doi.org/10.3390/su13147775
18. Lundberg JO, Farkas-Szallasi T, Weitzberg E, Rinder J, Lidholm J, Änggård A, Hökfelt T, Lundberg JM, Alving K, 1995. High nitric oxide production in human paranasal sinuses. Nature Medicine 1(4):370–373. https://doi.org/10.1038/nm0495-370 ; and Lundberg JO, Settergren G, Gelinder S, Lundberg JM, Alving K, Weitzberg E, 1996. Inhalation of nasally derived nitric oxide modulates pulmonary function in humans. Acta Physiologica Scandinavica 158(4):343–347. https://doi.org/10.1046/j.1365-201X.1996.557321000.x
19. Weitzberg E, Lundberg JO, 2002. Humming greatly increases nasal nitric oxide. American Journal of Respiratory and Critical Care Medicine 166(2):144–145. https://doi.org/10.1164/rccm.200202-138BC
20. Ge Hong 葛洪 (attributed). 神仙傳 Shenxian zhuan (Biographies of immortals), biography of Liu Gen 劉根, “courtesy name Jun’an” (字君安). Chinese text, Chinese Text Project edition, accessed 18 October 2026. https://ctext.org/shen-xian-zhuan/8/liugen/zh
21. Harper D, 1998. Early Chinese Medical Literature: The Mawangdui Medical Manuscripts. London and New York: Kegan Paul International, pp. 125–126 and note.
22. Bokenkamp SR, 2008. Lingbao. In: Pregadio F (ed.), The Encyclopedia of Taoism. London and New York: Routledge. Reproduced online by Golden Elixir, accessed 18 October 2026. https://goldenelixir.com/publications/eot_lingbao.html
23. 道教文化中心資料庫 (Daoist Culture Centre database). 高上玉皇胎息經 (Gaoshang yuhuang taixi jing), entry, accessed 18 October 2026. https://zh.daoinfo.org/wiki/高上玉皇胎息經
24. Zou Xuan 鄒鉉 (ed.), Yuan dynasty. 壽親養老新書 Shouqin yanglao xinshu, juan 3: 太上玉軸六字氣訣 (Taishang yuzhou liuzi qijue), attributed to Zou Pu’an (Zou Yingbo). Chinese text, Siku quanshu edition on Wikisource, accessed 18 October 2026. https://zh.wikisource.org/wiki/夀親養老新書_(四庫全書本)/卷3

Source quality note: [1], [2], [4], [7], [8], [9], [10], [11], [12], [20] and [24] are primary Chinese texts, read in Wikisource, Kanripo or Chinese Text Project editions; the translations are our own working translations. [8] is a modern transcription of a damaged excavated manuscript. [6] is the museum’s own description of the jade object, including its chosen reading of a disputed inscription. [5] is an official dictionary and gives modern definitions, not historical evidence. [3] and [22] are scholarly reference works, and [21] is a scholarly monograph. [23] is a Daoist reference database, used only for the tentative Tang date of the Taixi jing; please regard that date as uncertain. [11] is the anthology in which the text appears; its compiler’s undated preface places it after Emperor Zhenzong’s death in 1022, so it gives only a latest possible date. The identification of Liu Jun’an in [4] with Liu Gen in [20] is our own suggestion. [13] and [14] are official publications of the body that created the 2003 standard form. [15] is a large meta-analysis; [16] and [17] are small single-session lab studies; [18] and [19] are small laboratory studies from one research network. None of [15]–[19] tested Liu Zi Jue.