RESPIRATORY MUSCLE TRAINING ON DIAPHRAGM THICKNESS, PULMONARY FUNCTION TEST AND RESPIRATORY MUSCLE STRENGTH IN HEALTHY YOUNG ADULTS: A RANDOMIZED CONTROLLED TRIAL

Abstract

Background: Respiratory muscle training (RMT) has been proposed as an effective means to increase the
strength of the inspiratory and expiratory muscle. The RMT offers resistance to inhalation and exhalation
and causes an increased strain on the respiratory muscles.
Purpose: The aim of this study was to examine whether simultaneous RMT training (Both on inspiration &
expiration) resulted in changes in diaphragm thickness, respiratory muscle strength and pulmonary function
in healthy young adults.
Methods: In this study we evaluated the effect of 8 week (10 sessions per week) simultaneous RMT
training program in 60 healthy young adults. The participants were stratified for age and aerobic capacity;
and randomly assigned either to the experimental group (n=30) or to the control training group (n=30). The
program consisted of 8 weeks during which the experimental group performed RMT training (Power lung)
program of differing intensities and the control group performed simultaneous RMT training at baseline.
Pressure threshold respiratory muscle training was undertaken at the 30-repetition maximum load (50% of
the peak inspiratory and expiratory mouth pressure, MIP or MEP, respectively). Each subject underwent
testing of pulmonary function test, maximum inspiratory and expiratory pressures (MIP and MEP) and
diaphragmatic thickness (tdi) was measured via two-dimensional B-mode ultrasound.
Results: The respiratory muscle training group demonstrated significant increase in FVC, FEV1,
FEV1/FVC, Tdi, MIP, MEP compared with the control group. The mean diaphragm thickness in the
training group was 0.31 (0.19) while that of the control group was 00.00 (0.16). An increase was observed
in the training group at 50 % of their MIP- 102.37 cm H2O (9.93) to a mean of 109.23 (9.44) cm H2O &
MEP from a mean of 108.53 cm H2O (10.50) to a mean of 109.23 (9.44) cm H2O.
Conclusion: The finding of this study suggest that respiratory muscle training resulted in an increase of
diaphragm thickness, MIP, MEP, FVC, FEV1, FEV1/FVC in healthy young adults.