The effect of inspiratory muscle training method on the vital capacity

Introduction: The purpose of this study was to investigate the effects of special exercises training protocol of the inspiratory muscles on the vital capacity. Materials and Methods: 62 normal subjects' female students without any respiratory disease history participated in the study. At first, all subjects participated in a familiarization session to learn a correct pattern of ventilation and then the vital capacity was measured by spirometer. The vital capacity (VC) and %80 of maximum voluntary contraction (MVC) force of inspiratory muscles were assessed and monitored by computerized spirometry machine to the subjects .The subjects were randomly assigned in two control (n=30) and experimental (n=32) groups. Subjects in the experimental group were asked to perform a daily inspiratory exercise protocol including 6 inspiration muscle contraction (using %80 of MVC). Each contraction was separated with a rest time from the next contraction. The first rest time was 60 seconds and second rest time was 45 second and so on 30, 15, 10 seconds. The control group did not performance any other form of exercises. The VC was recorded at the end of each week in both groups and compared to the base line by paired t Test. Results: The results revealed that there are significant increase in the VC at the end of the fifth week (P