Inspiratory Muscle Training (IMT)

Inspiratory Muscle Training (IMT)

The diaphragm and the other muscles that draw air in can be trained like any other skeletal muscle. Inspiratory muscle training uses a small handheld device that makes you breathe in against an adjustable resistance, strengthening these muscles over a few weeks.¹

Who it helps

IMT is useful when inspiratory muscle weakness is contributing to breathlessness or reduced exercise tolerance — particularly in COPD, chronic heart failure, bronchiectasis, after prolonged mechanical ventilation, and around thoracic or cardiac surgery.² The gains are largest in people who start with measurable weakness of the breathing muscles.

How it is prescribed

We first measure your maximal inspiratory pressure (MIP) — how hard you can breathe in. Training is then set as a threshold load at roughly 30–50% of MIP, commonly about 30 breaths twice a day, with the load progressed as you get stronger. Benefits — less breathlessness, stronger inspiratory muscles and often a longer walking distance — build over 6–12 weeks.³

What to expect

A little fatigue in the chest and neck during training is normal; sharp pain or dizziness is not. Good technique matters — an upright posture, a tight seal on the mouthpiece, and a full, forceful breath in. We review the load and your technique at each visit so the training keeps challenging the muscles as they adapt.

Evidence

IMT reliably improves inspiratory muscle strength and reduces breathlessness in COPD,⁴ and improves functional capacity in chronic heart failure.⁵ It works best as one component of a broader rehabilitation plan rather than as a stand-alone treatment.

Training for strength, or for endurance

The load is not one number. Strength protocols use a higher proportion of your maximal pressure with fewer repetitions; endurance protocols use a lower proportion with more. That is why two people can be given quite different settings and both be training correctly — the target depends on what the training is for.⁶ The load is set from a measured pressure rather than guessed, and reset as you get stronger.

Breathing out can be trained too

Expiratory muscle strength training works the same way in reverse, using a device you breathe out against. It targets the abdominal and internal intercostal muscles, and is used where the problem is a weak cough, difficulty clearing secretions, swallowing safety or vocal loudness rather than breathlessness on exertion.⁶ If a weak cough is your main difficulty, see airway clearance and cough assist.

When training is not appropriate

IMT is generally well tolerated and has no formally recognised adverse effects, though muscle fatigue is common and is the usual reason people stop.⁶ It is not started, or is paused, in situations including a recent stroke, uncontrolled blood pressure, an unstable circulation, acute confusion, a perforated eardrum, a spontaneous pneumothorax, rib fractures, significant osteoporosis, or recent abdominal surgery.⁶ This is a list to check with your physiotherapist rather than to self-assess — several of these are temporary, and training can often start once the situation resolves.

References & evidence base

1. Gosselink R, De Vos J, van den Heuvel SP, et al. Impact of inspiratory muscle training in patients with COPD: what is the evidence? Eur Respir J 2011;37(2):416–425.
2. Bissett B, Gosselink R, van Haren FMP. Respiratory muscle rehabilitation in patients with prolonged mechanical ventilation: a targeted approach. Ann Am Thorac Soc 2020;17(2):141–149.
3. Charususin N, Gosselink R, Decramer M, et al. Randomised controlled trial of adjunctive inspiratory muscle training for COPD (the IMTCO study). Thorax 2018;73(10):942–950.
4. Beaumont M, Forget P, Couturaud F, Reychler G. Effects of inspiratory muscle training in COPD patients: a systematic review and meta-analysis. Clin Respir J 2018;12(7):2178–2188.
5. Smart NA, Giallauria F, Dieberg G. Efficacy of inspiratory muscle training in chronic heart failure patients: a systematic review and meta-analysis. Int J Cardiol 2013;167(4):1502–1507.
6. Winkle MJ, Sankari A. Respiratory Muscle Strength Training. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; updated 1 May 2024. Available at: ncbi.nlm.nih.gov/books/NBK603753

References are numbered in citation order (Vancouver/BMJ style) and were current at the time of writing. Guidelines are living documents — verify against the latest version before clinical use.