APD Movement Training
A self-guided movement program for episodes of visible abdominal distension
Last reviewed August 2026
The one job of this program
Let the lower chest come gently up.
Draw the abdomen gently in.
Keep breathing comfortably.
This is a coordination movement, not deep breathing or an abdominal workout. It should feel subtle and comfortable — more force is not better.
You are not trying to hold this position all day. The aim is to practise the coordinated lower-chest and abdominal-wall movement used in sensor-guided APD biofeedback.
Adapted from Barba et al. sensor-guided APD biofeedbackWho this was written for. Dr Douglas Samuel wrote this program for his own patients as a practical option while access to sensor-guided APD biofeedback remains limited in routine clinical practice. You are welcome to read and use these resources, but they provide general information rather than personal medical advice and are not a substitute for assessment by your own doctor. If you are not under Dr Samuel's care, discuss the program with your treating clinician. If they are unfamiliar with APD, the clinician guide below is written for them.
Before you start: unexplained weight loss, vomiting, gastrointestinal bleeding, fever, or severe or worsening abdominal pain need medical assessment rather than this self-help program.
First: is this the pattern this training was studied for?
APD biofeedback has been studied mainly in people with discrete episodes of visible abdominal distension — the abdomen becomes visibly or measurably larger than its less-distended baseline. This page adapts the movement taught in the Barba et al. sensor-guided protocols for self-guided home practice; that delivery method has not itself been validated.
There is a real change in abdominal size
- You are relatively flatter at some times and clearly larger at others.
- The change may appear after meals or build later in the day.
- Visible distension — not simply your resting abdominal shape — is the target you want to change.
Your abdomen is similarly prominent most of the day
If it is already prominent on waking and changes little with meals or across the day, the APD trials do not tell us whether this training will change that resting shape.
A prominent abdomen is not, by itself, the same thing as an episode of abdominal distension.
Learn the movement
Use the interactive trainer before starting the four-week program. Click each position, play the slow practice, and then open Common mistakes. Green represents lower-chest movement; red represents abdominal movement.
Research context: the successful trials used supervised sensor-guided biofeedback. In the 2024 study, participants then practised the same movement at home for 5 minutes before and after breakfast, lunch and dinner for four weeks. This unsupervised visual trainer is a practical translation of that movement; it has not itself been shown to be equivalent to sensor-guided biofeedback.
Quick check
Use this as your fast reference once you know the movement.
Breathing stays comfortable. The movement is small and coordinated.
The head or shoulders rise against the background instead of the lower chest moving subtly.
The abdomen moves inward but the lower-chest marker barely changes.
The body stiffens, strains or pushes beyond a comfortable range.
Rest one hand on your lower ribs and one over the navel. The top hand should feel a gentle lift or widening and the bottom hand should move slightly inward, while breathing remains comfortable.
Prefer written instructions? Open the step-by-step walkthrough Close the written walkthrough
Guided technique walkthrough
Use this written walkthrough if you prefer detailed instructions or want to check a specific part of the movement.
Side/oblique view. Sitting comfortably, shoulders relaxed, the abdomen relaxed in its natural shape — not pulled in. One marker at the lower rib margin, one near the navel, and a fixed horizontal reference behind the head or shoulders (a picture-frame edge, a shelf, or a small piece of tape on the wall).
What you would hear"APD retraining is not deep breathing, and it is not sucking your stomach in. Start by sitting comfortably with your abdomen relaxed in its natural shape — don't pull it in — and pick a fixed horizontal line behind your head or shoulders, like a picture-frame edge, a shelf, or a piece of tape. Everything you do is a gentle change from this relaxed position."
A small movement. Lower-costal marker rises slightly; abdominal marker moves inward. Head and shoulders stay fairly still. Comfortable breathing continues.
What you would hear"This is the position that matters: my lower chest comes gently up, my abdomen comes gently in, and I continue breathing comfortably. Watch how small it is. It should feel comfortable — more force is not better. This is the corrective end of the movement that you are learning to recognise."
Slow, unhurried movement between two positions: lower chest gently down with the abdomen gently out, then lower chest gently up with the abdomen gently in. Both positions clearly visible against the markers. No straining or forcing. Breathing continues throughout. The sequence finishes with the lower chest gently up and the abdomen gently in.
What you would hear"Now the practice itself. Move slowly between the two positions — lower chest gently down and abdomen gently out, then lower chest gently up and abdomen gently in. Make the movement clear enough that you can see and feel both positions, but keep it comfortable: don't force the range, brace or strain. Keep breathing comfortably throughout. Finish each practice sequence with the lower chest gently up and the abdomen gently in."
The upper chest rises substantially and the head or shoulders may lift against the fixed background reference.
What you would hear"Watch my head and shoulders against the background. They rise because I've taken a large breath. In the correct movement they stay fairly still."
Then: briefly show the correct movement again.
Abdomen forcefully sucked inward but the lower-costal marker barely moves.
What you would hear"A common mistake is pulling the abdomen in while the lower chest hardly moves. It can look convincing from the outside, but it is not the coordinated movement we are trying to learn."
Then: briefly show the correct movement again.
The body stiffens or you have to strain or force the shape rather than making a slow, comfortable movement.
What you would hear"If you have to stiffen your whole body, strain, or force the movement, relax and start again. For this self-guided exercise, keep breathing comfortably."
Then: show the correct movement, maintained for 3–4 ordinary breaths.
Phone set roughly 2 metres away, at lower-chest height and 30–45 degrees to the side. Two visible markers.
What you would hear"Now film yourself. Start relaxed, then move slowly between the two positions a few times, finishing at the corrective end and pausing there for three or four comfortable breaths. When you watch it back, ask only three questions: Did my lower chest come gently up? Did my abdomen move inward? Did I keep breathing comfortably?"
Three ticks appear: LOWER CHEST ✓ · ABDOMEN ✓ · BREATHING ✓
What you would hear"The first point is the one to check most carefully. Your lower chest needs to genuinely move without a deep breath, shoulder lift or leaning backwards. If all three are clear, start the program. If you are unsure, go back and practise the movement rather than practising a guess."
How you practise
Practice is a slow movement between two positions, not just holding one shape:
- Move slowly between the two positions.
- Make the movement clear enough that you can see and feel both positions, but keep it comfortable — do not force the range, brace or strain.
- Keep breathing comfortably. Don't deliberately hold your breath.
- Finish each practice sequence with the lower chest gently up and the abdomen gently in — the corrective end to recognise.
Why this movement is natural
This is not intended to be a forceful posture. It aims to reproduce the thoracoabdominal pattern that opposes APD, but on purpose.
Normally, when a meal or increased gas adds volume inside the abdomen, the body automatically accommodates that extra volume: the diaphragm relaxes upward and the abdominal wall gently increases its tone. This helps redistribute the contents and limits forward protrusion.
In APD, that response becomes reversed: the diaphragm contracts and moves downward while the abdominal wall relaxes and protrudes, producing much more visible distension.
The exercise teaches you to reproduce the healthier pattern voluntarily. That's why drawing the abdomen in by itself isn't enough — it can look similar from the outside without reproducing the same coordination.
Check yourself with your phone
You can give yourself feedback for free. Record the movement and watch it back — watching the replay can make subtle errors easier to recognise.
- Wear fitted clothing. Place one visible marker at the lower-rib margin and one near the navel.
- Choose a fixed horizontal reference behind your head or shoulders — a shelf, picture-frame edge or small piece of tape on the wall.
- Set your phone at about lower-chest height, roughly 2 metres away and 30–45° to your side — a slight oblique shows subtle rib movement better than a pure side-on view.
- Record about 10 seconds relaxed, then the slow alternating movement a few times, finishing at the corrective end and pausing there for a few comfortable breaths.
- Play it back and ask only three questions:
Did my lower chest subtly come up? · Did my abdomen come inward? · Could I keep breathing comfortably?
No phone? Use a mirror side-on, or the two-hand method above.
Technique check — during Week 1
Once you can watch your own replay, check the movement rather than judging whether your abdomen looks flat:
- Your lower chest moves gently up or wider. The lower-costal mark should move without a large breath, shoulder lift or leaning backwards.
- Your abdomen moves gently inward.
- Comfortable breathing continues.
Any no, or unsure → use the interactive trainer, written walkthrough and phone self-check again. Reduce the range rather than increasing effort.
Your four-week plan
The weeks are a sequence, not just repetition. Each week you lean on feedback a little less — a sensible way to build a skill you can keep, though how much to fade varies from person to person.
Learn the movement
Learn both positions and the slow movement between them, and learn to recognise the corrective end. Use the phone or mirror every session. Don't worry about symptoms yet.
Can I move slowly between both positions, breathing comfortably, and finish at the corrective end?
Do it without watching
Set up, then look away and do the movement. Look back afterwards to check.
Can I still do it when I'm not watching?
Transfer it into real life
Practise the movement in the situations when distension usually occurs — for example around meals or later in the day — without using immediate visible flattening as the test of success.
Can I reproduce the movement comfortably when I am actually distended or in the situations that usually trigger it?
Practise independently
Mostly without mirror or video, checking only occasionally. Use feedback again if the movement becomes unclear.
Can I reproduce the movement without equipment and without increasing effort?
How often
That home practice followed an initial sensor-guided biofeedback session.
This lower-dose option is pragmatic for unsupervised home use and has not been separately validated.
Whichever schedule you use, keep the movement comfortable. Stop and rest if you feel pain, dizziness, marked breathlessness or chest discomfort. The goal is coordination and improvement in episodes of distension over time — not holding in or flattening your resting abdomen.
Do not push through it. If repeated sessions reliably increase your distension, fullness, pain or breathlessness, stop the program and discuss that response with your clinician or physiotherapist.
Track almost nothing
Once a week, note the pattern across the week rather than judging one practice session:
- Typical or worst visible distension this week, 0–10.
- Compared with before training, are episodes less severe, less frequent or less troublesome? Better / Same / Worse.
- Optional: bloating / fullness, 0–10.
- Optional: a private side photo in similar clothing, posture, lighting and time of day — only if it feels helpful rather than distressing.
You do not need to repeatedly measure your waist. If objective tracking helps, use an occasional standardised side photo rather than turning each practice session into a contest to make the number smaller.
After four weeks — ask two separate questions
Can I perform the movement clearly? And, separately, have my episodes of visible distension meaningfully improved over the four weeks? Do not require the abdomen to visibly deflate on command, and do not assume that lack of improvement means poor technique.
Your movement is reproducible and, across the four weeks, your episodes of visible distension are meaningfully better.
→ Continue on your own and gradually rely less on visual feedback.
You cannot confidently reproduce the lower chest gently up / abdomen gently in movement without a large breath, lean or abdominal-only hollowing.
→ Use Technique Rescue for up to another 2 weeks. This is the group in whom further technique work makes sense.
You can reproduce the movement, but the severity, frequency or impact of your visible-distension episodes is not meaningfully different after four weeks.
→ Do not simply practise harder. APD may not be the dominant mechanism, or your pattern may not match the episodic distension studied in the trials. Return to the broader bloating/distension assessment pathway or discuss this with your clinician.
Technique Rescue — Weeks 5–6
Use this section only if the technique itself remains uncertain. If the movement is already clear but your distension has not improved, skip Technique Rescue and reconsider whether APD is the main mechanism.
- Go back to the guided walkthrough, open it again, and film yourself again.
- Slow the movement down further. Make both positions clear, but keep it comfortable — no forcing, bracing or straining, and keep breathing comfortably.
- Check the lower-costal marker really moves at the corrective end — not the abdomen alone. This is the commonest thing to get wrong.
- Finish each practice sequence at the lower chest gently up / abdomen gently in corrective end.
The movement is demonstrated in Barba et al. (2024), Supplementary Video 1 — scroll to the supplementary material. That demonstration is a supervised version recorded with sensors; for home practice, follow the walkthrough above. Optional background, not a step you have to follow.
After six weeks
→ Continue independently. Use video or mirror feedback only occasionally if you need to recalibrate the movement.
→ If available, see a physiotherapist or clinician familiar with APD movement retraining to help establish the movement rather than increasing effort.
If they are unfamiliar with APD, send them the clinician guide below.
→ Further repetitions are unlikely to answer the diagnostic question. Seek clinical review to reconsider whether APD is the dominant mechanism and whether another disorder of gut–brain interaction or another cause of distension is more relevant.
For physiotherapists and other treating clinicians: how to teach APD movement retraining
APD physiology
APD visible distension involves inappropriate diaphragmatic contraction/descent with anterior abdominal-wall relaxation and protrusion. The corrective target used in the 2024 wall-motion biofeedback protocol was diaphragmatic relaxation/upward movement, cued through costal elevation with abdominal-wall contraction. The patient-facing open-airway version keeps comfortable breathing throughout.
Corrective cue
Let the lower chest come gently up. Draw the abdomen gently in. Keep breathing comfortably.
The visible lower-chest movement is a practical training surrogate; it does not by itself prove diaphragmatic ascent. The key clinical task is coordinated lower-costal movement, abdominal-wall activation and preserved tidal breathing — not abdominal hollowing alone.
The mobilisation
The patient program teaches, from Week 1, a slow alternating mobilisation — chest down / abdomen out ↔ chest up / abdomen in — performed through a clear but comfortable range and finishing at the corrective pole. This mirrors the 2024 protocol, in which patients were first taught the corrective configuration (costal elevation with abdominal-wall contraction) and then guided to mobilise the diaphragm through the alternating manoeuvre. The chest-down / abdomen-out pole is part of the mobilisation, not merely a demonstration of the wrong direction.
Avoid teaching this as
- generic diaphragmatic / belly breathing;
- a big thoracic inspiration;
- rib flare;
- shoulder elevation;
- leaning backwards;
- forceful bracing, straining or Valsalva;
- forceful abdominal hollowing alone.
Breathing during the manoeuvre
For this self-guided program, patients should keep breathing comfortably and should not deliberately hold their breath, brace or strain.
In the 2024 biofeedback protocol, the alternating manoeuvre could be performed either with an open airway (breathing through the movement) or with a closed airway — moving air between chest and abdomen in a pendular fashion, with no air passing in or out through the mouth or nose while the chest and abdomen move against each other.
A brief, deliberate breath-hold during supervised pendular training is not the same as forceful bracing, straining or Valsalva. The open-airway instruction used in the patient program is a simplification chosen for unsupervised home training, not a claim that the closed-airway version is unsafe.
How to teach without formal biofeedback
Use observation; palpation / manual cueing; a mirror; phone / video replay; visual markers at the lower-costal margin and navel; and progressive withdrawal of feedback. These low-tech methods are not proven equivalent to sensor-guided biofeedback.
If acquisition is difficult
Slow the alternation further and reduce the range rather than increasing effort; cue manually at the lower costal margin and navel; and confirm the patient can reach, recognise and sustain the chest-up / abdomen-in pole with tidal breathing preserved, rather than substituting abdominal hollowing.
Progression: acquisition → retention → transfer
Can the patient perform the movement with tidal breathing preserved? Reproduce it without cueing? Reproduce it later? Transfer it into the situations in which genuine visible distension occurs? Treatment response should then be judged across time, not by requiring immediate visible reduction during one practice attempt.
Physio endpoint
Establish whether the patient can reproducibly perform the corrective APD movement, including in the circumstances in which genuine distension occurs. Assess clinical benefit over repeated episodes and over time rather than requiring immediate visible deflation.
Referral onward
If correct technique is established but genuine episodes of visible distension do not meaningfully improve, do not assume technique failure. Reconsider whether APD is the dominant mechanism, whether the patient has the discrete episodic phenotype studied in the trials, and whether overlapping or alternative causes are more relevant.
Evidence lineage
Barba, Accarino and Azpiroz (2017) used EMG-guided biofeedback to train reduced intercostal and diaphragmatic activity with increased anterior abdominal-wall activity, with benefit sustained to six months. Barba, Livovsky, Accarino and Azpiroz (2024) used thoracoabdominal wall-motion–guided biofeedback to teach the corrective configuration (chest up – abdomen in) and then mobilisation of the diaphragm through the alternating manoeuvre, with patients practising the same exercises at home.
This program therefore translates the movement taught in those studies into a self-guided visual training format, developed as a practical option for patients where access to specialist sensor-guided biofeedback is limited or difficult. The authors of the 2017 and 2024 studies did not develop or test this self-guided version, and citation of their work does not imply endorsement. Neither trial validates this specific self-taught delivery; the 2024 authors identify noninstrumental or visually guided training as an avenue for future research. The Week-4 and Week-6 decision points separate failure to acquire the movement from failure of a correctly performed movement to improve symptoms; those are different clinical problems.
References
- Barba E, Accarino A, Azpiroz F. Correction of abdominal distention by biofeedback-guided control of abdominothoracic muscular activity in a randomized, placebo-controlled trial. Clin Gastroenterol Hepatol. 2017;15(12):1922–1929. doi:10.1016/j.cgh.2017.06.052
- Barba E, Livovsky DM, Accarino A, Azpiroz F. Thoracoabdominal wall motion–guided biofeedback treatment of abdominal distention: a randomized placebo-controlled trial. Gastroenterology. 2024;167(3):538–546. doi:10.1053/j.gastro.2024.03.005
- Melchior C, Hammer H, Bor S, et al. European Consensus on Functional Bloating and Abdominal Distension — ESNM/UEG recommendations for clinical management. United European Gastroenterol J. 2025;13(9):1613–1651. The consensus specifically supports biofeedback-guided re-education in patients with discrete episodes of visible abdominal distension and notes that non-instrumental training remains under development.
- unintentional weight loss;
- vomiting;
- persistent diarrhoea;
- blood in the stools;
- fevers or night sweats; or
- severe or worsening abdominal pain.