How do persons with multiple sclerosis perceive effort during exercise?

INTRODUCTION: The symptoms and pathophysiology of multiple sclerosis (MS) could affect how exercise is perceived, including ratings of perceived exertion (RPE). The purpose of this cross-sectional study was to examine absolute and relative RPE during exercise in a large sample of persons with MS. METHODS: 135 persons with MS (Patient-Determined Disease Steps (PDDS) scale mdn = 2.0, IQR = 3.0) and 64 healthy controls completed a maximal, incremental exercise test on a cycle ergometer with open-circuit spirometry for measuring exercise variables (i.e., VO2peak). RPE were obtained during the last 10 seconds of each minute using Borg's 6-20 scale. Data were analyzed in the overall sample, in a subsample of participants that continued exercise at and/or above 120W (84 persons with MS and 57 controls), and in a sample of persons with MS (n = 55) and controls (n = 55) that were matched on age, sex, and VO2peak. RESULTS: ANOVA and post-hoc analyses revealed group differences in RPE at absolute exercise intensities (W) in the overall sample with the exception of the lowest intensity (W= 15) and in the subsample and matched sample at only at the highest intensity (W= 120). There were no statistically significant differences in RPE relative to VO2peak (mL/kg/min) in the overall sample, subsample and matched sample, such that RPE increased similarly between groups as a function of relative exercise intensity. DISCUSSION: Persons with MS reported similar RPE to exercise compared to healthy controls when data were expressed in terms of relative exercise intensity. RPE can be utilized for exercise prescriptions and documenting adaptations to exercise training in persons with MS.