Objectives: The objectives of this study were to evaluate cardiopulmonary and metabolic functions in patients with multiple sclerosis (MS) and to clarify the relationship between these functions and neurological deficits, respiratory involvement, fatigue and quality of life.

Materials and methods: Twenty-five patients with MS and 15 healthy controls were included in the study. Cardiopulmonary and metabolic responses to maximum exercise were investigated with an electronically braked arm crank ergometer. A computerized gas analysis system collected and analysed expired gases during exercise.

Results: In the present study, significant respiratory muscle weakness, and decreased aerobic performance and cardiopulmonary and metabolic responses to maximum exercise were determined in patients with MS.

Conclusions: As respiratory muscle function plays a strong role in aerobic capacity and in most of the cardiopulmonary and metabolic responses to exercise, measurement of respiratory muscle strength and endurance should also be carried out in the MS population.