Effect of endurance training on cardiopulmonary fitness in people with multiple sclerosis

Introduction: Disturbances associated with Multiple Sclerosis (MS) can be due to the pathologic process of the disease or insufficient physical fitness. The benefits of exercise in improving cardiopulmonary fitness have been demonstrated in animal studies and also clinical trials on cardiovascular patients and healthy human cases; however, its effectiveness in people with MS(pwMS) is still unknown. people with MS often engage in rehabilitation programs for exercise tolerance improvement. Therefore, it is necessary to investigate the effect of this specific intervention on cardiopulmonary fitness of these patients. The present study intended to illustrate the etiology of exercise intolerance in pwMS and also the effects of exercise on these etiological factors.

Methods and results: The present interventional study included 21 female patients suffering from Relapsing-Remitting MS (RR-MS) who had a mean age of 35 ± 5.18 years and the Expanded Disability Status Scale (EDSS) scores of 1 to 4. All the participants underwent Cardiopulmonary Exercise Testing (CPET) on an ergometer pre- and post-intervention. The intervention included 18 sessions of endurance training using a stationary bicycle with an intensity of 70% of the peak Heart Rate (HR) or 60% of the peak VO₂ (Volume of oxygen consumption) under the supervision and cardiac monitoring. A total of 24 variables, including the parameters cardiopulmonary fitness (aerobic fitness), were investigated. Also, all the maximal variables were analyzed in the same RER(Respiratory Exchange Ration) (a mean RER of 0.92) pre- and post-intervention. According to the results, a total of 17 variables out of 24 study variables had significant changes (P < 0.05).

Conclusion: The present study showed that even a short, 6-week course of aerobic exercise could change the peak HR and VO₂, improving the cardio pulmonary fitness in these patients. This indicates the adaptation of the cardiopulmonary system to exercise in pwMS. In other words, these cardiopulmonary fitness variables improvement due to exercise demonstrates that this pathology is not merely caused by the MS-induced Central Nervous System (CNS) involvement and can be improved by improving cardiopulmonary fitness.