The process of increasing the strength and endurance of the muscles of breathing is called ventilatory muscle training. This technique usually focuses on the muscles of inspiration. VTM has been used in the treatment of patients with a variety of acute and chronic pulmonary disorders associated with weakness, atrophy, or insufficiency of the muscles of inspiration, specifically diaphragm and external intercostals. It has been suggested that principles of overload and specificity of training apply to skeletal muscles throughout the body, including the muscles of ventilation.

Three forms of ventilatory muscle training involve following:

Weight training to strengthen the diaphragm
Inspiratory resistance training
Incentive respiratory spirometry


Incentive spirometry is a form of low level resistance training that emphasizes sustained maximal inspiration. A synonymous term is sustained maximal inspiratory maneuver, which is performed with or without a spirometre. The patient inhales through the a spirometre that provided visual or auditory feedback as the patient breathes in as deeply as possible.Incentive spirometry increases the volume of air inspired and has been used to prevent alveolar collapse in postoperative conditions and to strengthen weak inspiratory muscles in patients with neuromuscular disorders.

Procedure for Incentive respiratory spirometry:

Place the patient in a comfortable position (Supine or semiupright).
Have the patient take three to four slow easy breaths.
Have the patient maximally exhale with the fourth breath.
Then have the patient place the spirometre in the mouth and maximally inhale through the spirometre and hold the inspiration for several seconds.
This sequence is repeated 5 to 10 times several times per day.

Precaution:

Avoid prolonged periods of any form of resistance training for inspiratory muscles. Unlike muscles of extremity, the diaphragn cannot totally rest to recover from a session of resistance exercises. Use of accessory muscles of inspiration (neck muscles) is a sign that the daiphragm is beginning to fatigue.