The standing breath, lying down — voluntary control of breathing organisation in supine rest and sustained bridging

Lying on the back at rest, the body breathes deeply by itself, and it does so with the abdomen; standing at rest, deep breathing needs another mechanism, in which the trunk widens and the abdominal wall keeps its place. In this paper, deep refers to where in the trunk the breathing movement takes place, not to the amount of air. The author analyses two uncut videos recorded on 30 October 2026: five minutes lying on his back, in which he changes at will between the mechanism the body uses lying down and the one it needs standing, and nine minutes holding a bridge – feet and shoulders on the floor, pelvis lifted – while breathing throughout. A camera at floor level reads the upper contour of the trunk against the wall; the nipple and a mole about 19 cm apart give the scale. With the lying mechanism the abdomen rises by 1.4–2.7 cm per breath and the chest by 1–4 mm, seven to nine times a minute. With the standing mechanism, still lying down, abdomen and chest rise by the same 6–8 mm, the whole trunk lifts, the rib cage travels 1–1.6 cm upward and 1.4 cm toward the head, and the breath slows to 3.6 a minute. He holds the bridge for 8 min 29 s without reaching a limit and breathes 50 times, nearly all with the standing mechanism. When he lets go of the standing mechanism in the bridge, the lying mechanism takes over at once while the pelvis stays up. The skin does not redden in either recording. The observations are compared with studies of body position and breathing, of the diaphragm under load and of the bridge exercise, in which breathing is instructed but not measured.