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.