['To determine the impact of a single exercise session on function, fatigue, and sensory symptoms for people with multiple sclerosis (MS).', 'This pilot study was designed as a before-after trial. Demographic and response-to-exercise measures were taken before exercise, repeated immediately after exercise, and followed up again 24 hours later.', 'Three metropolitan centers of an MS society.', 'A prospective sample of 34 subjects with MS who were referred for physiotherapy for an exercise program and who could attend an MS society center.', 'Subjects performed an individually prescribed exercise session, which was at a commencement level and included strengthening, stretches, and fitness exercises. Subjects exercised for between 5 to 45 minutes (mean, 17.4 min) at an intensity of 7 to 17 (median, 12) on the Borg rating of perceived exertion (RPE) scale.', 'All outcome measures were self-rated by subjects and included the Borg RPE scale, a questionnaire for sensory symptom description, and visual analog scales for rating of fatigue, function, and intensity of sensory symptoms.', 'Subjective levels of fatigue and function immediately postexercise and 24 hours postexercise did not differ significantly from pre-exercise levels. However, over 40% of subjects experienced a temporary increase in number of sensory symptoms, 44% experienced an increase in the intensity of sensory symptoms, and 29% experienced an increase in both number and intensity immediately postexercise.'] Is symptom change with exercise a temporary phenomenon for people with multiple sclerosis?