Ratings of perceived effort during expiratory pressure tasks in healthy adults

Purpose

Expiratory muscle strength training (EMST) is a resistance exercise used to improve maximal expiratory pressure and airway protective functions (cough and swallow) in clinical populations. Although ratings of perceived exertion/effort (RPE) are commonly used in exercise prescription and monitoring, they have been underutilized in EMST and require investigation. Our study aims were to: (1) examine how healthy adults rate their effort using the EMST-150 device and MicroRPM respiratory manometer; (2) assess variability in RPE; and (3) compare RPE and relative expiratory pressures obtained from the two devices.

Method

Healthy adults completed thirty randomized expiratory maneuvers into a respiratory manometer and an EMST-150 device. RPE was measured using the Borg Category Ratio Scale. Linear mixed multilevel models were used for Aim 1 and 3, and coefficient of variation was used for Aim 2.

Results

Twenty healthy adults (Median age: 24.5 years) participated. Results demonstrated a strong positive relationship between resistive load and perceived effort when using both devices. Intra-individual variability in perceived effort decreased as resistive load increased. Participants produced an average of 18.2 % lower expiratory pressure when blowing into the manometer (relative to their maximum) than when blowing into the EMST device.

Discussion

Our results support the utilization of RPE in EMST research and clinical practice. The addition of RPE as a measure of intensity during respiratory exercise prescription may be used in future research to help refine EMST protocols and improve rehabilitation outcomes.