This is a longitudinal study to examine the effects of a short-term training program on neurofilamet and GFAP plasma levels. Participants will be divided in two groups: control group (moderate aerobic training) and active group (resistance training). The change in biomarkers will be analyzed pre and post intervention in both groups. Differences between groups will be also evaluated by investigators.

Multiple sclerosis is a dysimmune and neurodegenerative disease of the central nervous system. Despite highly effective drug, multiple sclerosis represents the main cause of non-traumatic disability in young people. Interventions based on physical exercise have a positive impact on the course of the disease, although the pathophysiological mechanisms responsible for this benefit remain unknown. This project aims to investigate the impact of physical exercise on neuronal destruction in patients with multiple sclerosis.

To do this, the investigators will study the evolution of the concentrations of two markers of neuronal injury, acidic gliofibrillary protein (GFAP) and light chain neurofilaments (Nfl) in two groups of patients: a control group and a second group subjected to a supervised resistance physical exercise program performed during 10 weeks. Marker values will be compared before and after the intervention and between groups. The results will allow the investigators to delve into the pathophysiology of multiple sclerosis and the mechanism through which physical exercise impacts on the disease. In addition, the investigators will generate knowledge that will allow us to reinforce the idea of integrating physical exercise as part of the treatment in multiple sclerosis.

Project within the framework of the GRS(Gerencia Regional de Salud, Castilla y Léon) 28/10/A1/2023

Inclusion Criteria:

1. - Diagnosis of multiple sclerosis according to the 2017 Mc Donald criteria (Thompson A et al).
2. - Age > 18 years - up to no age limit
3. - Disability assessed by the EDSS (Expanded disability status scale) with a score less than or equal to 4.
4. - Clinical stability. Not having had an outbreak of the disease in the last 6 months.
5. - No changes in the disease-modifying treatment in the last 6 months or no treatment.
6. - Radiological stability. Patients with last MRI (magnetic resonance imaging) performed without inflammatory activity (absence of new lesions on T2 sequences or lesions that enhance with gadolinium).
7. - They must sign the informed consent

Exclusion Criteria:

1. - Patients with a high level of physical activity according to the International Physical Activity Questionnaire(IPAQ) or latest WHO (World Health Organization) recommendations on physical activity
2. - Pregnant or breastfeeding patients.
3. - Concomitant pathologies that limit the performance of physical exercise

A double-blind system will be maintained in which the exploring neurologists and the patient will not know the assigned therapeutic group. Randomly assigned to one or the other group.