Inspiratory muscle training
Alves MJ, Borile S, Consolim-Colombo FM (2012) Inspiratory muscle training reduces sympathetic nervous activity and improves inspiratory muscle weakness and quality of life in patients with chronic heart failure: a clinical trial. J Cardiopulm Rehab Prev, 32, 5, 255 261
daily 30-minute sessions of inspiratory muscle training can improve quality of life in heart failure patients

Basso-Vanelli RP, Di Lorenzo VA, Labadessa IG et al (2016) Effects of inspiratory muscle training and calisthenics-and-breathing exercises in COPD with and without respiratory muscle weakness. Respir Care; 61(1):50-60. doi: 10.4187/respcare.03947

Bissett BM, Leditschke IA, Neeman T et al (2016) Inspiratory muscle training to enhance recovery from mechanical ventilation: a randomised trial. Thorax; 71(9):812-9. doi: 10.1136/thoraxjnl-2016-208279

Borge CR, Hagen KB, Mengshoel AM et al (2016) Effects of controlled breathing exercises and respiratory muscle training in people with chronic obstructive pulmonary disease: results from evaluating the quality of evidence in systematic reviews. BMC Pulm Med; 14:184. doi: 10.1186/1471-2466-14-184
IMT can reduce SOB, fatigue and disease-specific QoL

Brocki BC, Andreasen JJ, Langer D et al (2016) Postoperative inspiratory muscle training in addition to breathing exercises and early mobilization improves oxygenation in high-risk patients after lung cancer surgery: a randomized controlled trial. Eur J Cardiothorac Surg; 49(5):1483-91. doi: 10.1093/ejcts/ezv359

Brunherotti MAA, Bezerra PP, Bachur CK et al (2012) Inspiratory muscle training in a newborn with anoxia who was chronically ventilated. Phys Ther, 92, 6, 865-71

Camcıoğlu B, Boşnak-Gl M, Karadallı MN et al (2016) The role of inspiratory muscle training in sickle cell anemia related pulmonary damage due to recurrent acute chest syndrome attacks. Case Reports Hematology; 780159. doi: 10.1155/2015/780159
IMT has shown improvements in exercise capacity, QoL, SOB, fatigue and pain

Chatham K et al (2009) Suspected statin-induced respiratory muscle myopathy during long-term inspiratory muscle training in a patient with diaphragmatic paralysis Phys Ther, 89, 257-66
high-intensity IMT improved inspiratory muscle performance, symptoms and functional status; improvements were lost after statins were started, but regained when statins withdrawn.

Cordeiro AL, Melo TA, Neves D et al (2016) Inspiratory muscle training and functional capacity in patients undergoing cardiac surgery. Braz J Cardiovasc Surg; 31(2):140-4. doi: 10.5935/1678-9741.20160035

Drăgoi RG, Amaricai E, Drăgoi M et al (2016) Inspiratory muscle training improves aerobic capacity and pulmonary function in patients with ankylosing spondylitis: a randomized controlled study. Clin Rehabil; 30(4):340-6. doi: 10.1177/0269215515578292

Ferreira GD, Ana CC, Costa RDM et al (2016) Respiratory training improved ventilatory function and respiratory muscle strength in patients with multiple sclerosis and lateral amyotrophic sclerosis: systematic review and meta-analysis. Physiother; 102(3):221228

Ghl O, Walker DJ, Walterspacher S et al (2016) Respiratory muscle training: state of the art. Pneumologie; 70(1):37-48. doi: 10.1055/s-0041-109312

Granados J, Gillum T, Castillo W (2015) 'Functional' respiratory muscle training during endurance exercise causes modest hypoxemia but overall is well tolerated. J Strength Cond Res. Aug 28.

Hill K, Jenkins S, Hillman DR, Eastwood PR (2004) Dyspnoea in COPD: can inspiratory muscle training help? Austr J Physiother, 50,169-80.
excellent explanation of the physiology of breathlessness
evidence that specific loading of the respiratory muscles can reduce SOB

Jung J, Kim N (2016) Relative activity of respiratory muscles during prescribed inspiratory muscle training in healthy people. J Physical Ther Science; 28(3):1046-1049. doi: 10.1589/jpts.28.1046.

Karadallı MN, Boşnak-Gl M, Camcıoğlu B et al (2016) Effects of inspiratory muscle training in subjects with sarcoidosis: a randomized controlled clinical trial. Respir Care; 61(4):483-494
for people with early-stage interstitial disease such as sarcoidosis, IMT  exercise capacity,  severe fatigue and dyspnoea perception

Katsura M, Kuriyama A, Takeshima T et al (2015) Preoperative inspiratory muscle training for postoperative pulmonary complications in adults undergoing cardiac and major abdominal surgery. Cochrane Database Syst Rev;10:CD010356. doi: 10.1002/14651858.CD010356.pub2
preoperative IMT is associated with reduced postoperative atelectasis, pneumonia and duration of hospital stay

Kulkarni SR et al (2010) Pre-operative inspiratory muscle training preserves postoperative inspiratory muscle strength following major abdominal surgery a randomised pilot study
Ann R Coll Surg Engl; 92(8): 700705. doi: 10.1308/003588410X12771863936648

Kuo Y-C (2017) Short-term expiratory muscle strength training attenuates sleep apnea and improves sleep quality in patients with obstructive sleep apnea. Resp Physiol Neurobiol; 243: 86-91

Langer D, Charususin N, Jcome C et al (2015) Efficacy of a novel method for inspiratory muscle training in people with chronic obstructive pulmonary disease. Phys Ther; 95(9):1264-73. doi: 10.2522/ptj.20140245
electronic flow-resistive device which stores data

Martm-Valero R, Almeida MDLAC, Casuso-Holgado MJ et al (2015) Systematic review of inspiratory muscle training after cerebrovascular accident. Respir Care; 60(11):1652-1659

Nikoletou D, Man WD, Mustfa N et al (2016) Evaluation of the effectiveness of a home-based inspiratory muscle training programme in patients with chronic obstructive pulmonary disease using multiple inspiratory muscle tests. Disabil Rehabil; 38(3):250-9. doi: 10.3109/09638288.2015.1036171

Park JW, Kweon M, Hong S (2015) The influences of position and forced respiratory maneuvers on spinal stability muscles. J Physical Ther Science; 27(2):491-493. doi:10.1589/jpts.27.491

Ogiwara S, Miyachi T (2002) Effect of posture on ventilatory muscle strength. J Phys Ther Sci, 14, 1-5
training is most effective in the upright position

Ray AD (2013) A combined inspiratory and expiratory muscle training program improves respiratory muscle strength and fatigue in multiple sclerosis. Arch Phys Med Rehabil, 94(10):196470

Reid WD (2008) Effects of inspiratory muscle training in cystic fibrosis: a systematic review. Clin Rehab, 22, 10-11, 100313
weak evidence for the benefit of IMT in CF

Sales AT, Fregonezi GA, Ramsook AH et al (2016) Respiratory muscle endurance after training in athletes and non-athletes: A systematic review and meta-analysis. Phys Ther Sport; 17:76-86. doi: 10.1016/j.ptsp.2015.08.001

Smeltzer SC et al (1996) Expiratory training in multiple sclerosis. Arch Phys Med Rehab, 77, 909-12
expiration can be helped by expiratory muscle training in MS

Smith BK, Gabrielli A, Davenport PW et al (2014) Effect of training on inspiratory load compensation in weaned and unweaned mechanically ventilated ICU patients. Respir Care; 59(1):2231

Sutbeyaz ST (2010) Respiratory muscle training improves cardiopulmonary function and exercise tolerance in subjects with subacute stroke. Clin Rehabil, 24, 3, 240-50

Turner LA, Tecklenburg-Lund SA, Chapman RF et al 2012) Inspiratory muscle training lowers the oxygen cost of voluntary hyperpnea. J Appl Physiol, 112, 127-134

Vergs S, Flore P, Nantermoz G (2009) Respiratory muscle training in athletes with spinal cord injury. Internat J Sports Med, 30, 526-32.
respiratory muscle training can reduce breathlessness in athletes with spinal cord injury.

Weiner P et al (1995) Inspiratory muscle training during treatment with corticosteroids. Chest, 107, 1041-4
IMT can prevent muscle deterioration caused by steroids

Weiner, P, Magadle, R, Beckerman, M et al (2003) Specific expiratory muscle training in COPD. Chest, 124, 468-473
expiratory muscles can be trained in patients with COPD, with improvement of both strength and endurance, leading to increased exercise performance and no change in breathlessness.

Weiner, P, Magadle, R, Beckerman, M, et al (2004) Maintenance of inspiratory muscle training in COPD patients: one year follow-up. Eur Respir J, 23, 61-65
the benefits of 12-weeks IMT are lost gradually over one year without maintenance training.

Weiner P, Weiner M (2006) Inspiratory muscle training may increase peak inspiratory flow in COPD. Respiration; 73, 151-56

CABG = coronary artery bypass graft
CF = cystic fibrosis
IMT = inspiratory muscle training
QoL = quality of life
SOB = shortness of breath