Maximal shortening of inspiratory muscles: effect of training

Abstract

Normal subjects can increase their vital capacity by appropriate training. We tested whether that change can be achieved by greater maximal shortening of the inspiratory muscles without concomitant increases in peak static inspiratory pressures. Sixteen healthy volunteers participated in the study: eight were randomly assigned to make 20 inhalations to total lung capacity, held for 10 s with the glottis open, each day for 6 wk; the remainder served as nontraining controls. Before and after the 6-wk study period, we made multiple determinations of lung volumes and of curves relating lung volume to maximal static inspiratory (and expiratory) pressure. Control subjects had no significant changes from base line in any variable. In the training group, the mean vital capacity increased 200 +/- 74 ml (P less than 0.05) or 3.9 +/- 1.3% (P less than 0.02), without a significant change in residual volume. After training, the mean maximal inspiratory pressure at the airway opening (PI) at a lung volume equal to the base-line total lung capacity was 27 +/- 8 cmH2O in this group (vs. zero before training; P less than 0.02). Values of PI in the mid-vital capacity range did not change. We conclude that in response to appropriate training stimuli inspiratory muscles can contract to shorter minimal lengths, a capacity potentially important in progressive pulmonary hyperinflation.

Exercise Training 3—exercise Training in Pulmonary Rehabilitation

“…Other authors have also showed a small increase in the mean VC of healthy subjects after inspiratory muscle training. 20,24 However, the training the present Study differs from others in that our training consisted of maximal inhalation to TLC, followed by GI. This may result in a stretching effect rather than an increase in muscle strength.…”

“…12,13 Opinions differ as to whether it is possible to improve pulmonary function by any form of training. 2,[14][15][16][17][18][19][20] It is not clear if larger lung volumes have developed due to genetic selection or training of the respiratory muscles during singing or swimming. 17,18,21 One accepted fact regarding the response of the lungs to exercise is that large lung volumes generally reflect genetic influences and body size characteristics because exercise training does not appreciably change static lung volumes.…”

“…Studies have shown that some singers, wind-instrument players and swimmers have large lung volumes compared to a normal population. 17,21,23 Fanta et al 20 have reported that VC can be increased to a small extent in healthy adults (non-athletes) by making inhalations to TLC with the glottis open. 20 Respiratory muscle training (RMT) has also shown various results, with some studies indicating that VC may be increased in adults by RMT.…”

“…17,21,23 Fanta et al 20 have reported that VC can be increased to a small extent in healthy adults (non-athletes) by making inhalations to TLC with the glottis open. 20 Respiratory muscle training (RMT) has also shown various results, with some studies indicating that VC may be increased in adults by RMT. 24,25 Leith and Bradley 24 showed that normal subjects could improve their ventilatory muscle strength and endurance with a specific ventilatory muscle training program This is in contrast to other studies of RMT, which do not show any changes in lung volumes.…”

Respiratory Functions of Volleyball Players According To Specific Playing Positions

“…There might be increase in the maximal shortening of the inspiratory muscles as an effect of training, which has been shown to improve the respiratory function parameters [17].…”