Ratings of perceived exertion during aerobic exercise in multiple sclerosis.

Abstract

To compare ratings of perceived exertion (RPEs) during aerobic exercise in people with multiple sclerosis (MS) and control participants. Prospective experimental study. An exercise testing laboratory. Sedentary adults (n=12) with mild MS (Expanded Disability Status Scale score < or = 3) aged 30 to 45 years and sedentary age-matched and sex-matched controls (n=12). All participants underwent a graded aerobic exercise test on a cycle ergometer with breath-by-breath gas measurements and continuous heart rate monitoring. After completing the Modified Fatigue Impact Scale, participants rated their effort sense every 30 seconds during exercise using the modified Borg 10-point scale. The 2 study groups showed similar baseline characteristics except for higher fatigue scores in the MS group. There were no significant differences for any fitness measure, including oxygen cost slope (in VO(2) x min(-1) x W(-1)), VO(2), or work rate during exercise. Neither heart rate nor RPE--measured at 25%, 50%, 75%, and 100% of VO(2)peak--differed between groups. Despite greater reported fatigue levels, participants with MS showed similar RPE and physiologic responses to submaximal and maximal exercise compared with controls. In MS, the Borg 10-point scale may help improve evidence-based exercise prescriptions, which otherwise may be limited by fatigue, motor impairment, heat sensitivity, or autonomic dysfunction.