INSPIRATORY MUSCLE TRAINING AND RESPIRATORY SENSATION DURING TREADMILL EXERCISE

We studied whether inspiratory muscle training (IMT) changed respirato ry sensation during exercise in 12 healthy women; IMT was performed tw ice daily, for 15 minutes, using a pressure threshold device and conti nued for 4 weeks. The inspiratory threshold was set to 30 percent of e ach individual's maximal inspiratory pressure (PImax). Breathing effor t was evaluated during a progressive exercise test using Borg scale. A fter IMT, both PImax and maximal transdiaphragmatic pressure increased by 30 percent in the training group (p<0.05) but did not change in th e control group. Prior to IMT, the Borg score increased in proportion to exercise grade. The difference in the sensory score-exercise stage curves before and after IMT in the training group was not significant. No significant difference was noted in the relationship of the Borg s core to minute ventilation before and after 4 weeks in either group. W e concluded that IMT may not affect respiratory sensation during exerc ise in normal subjects, although IMT increases diaphragmatic strength.