Can Fatigability Neuromuscular Explain Chronic Fatigue in People With Multiple Sclerosis?

Inclusion Criteria: For Patients: * Aged ≥ 18 and ≤ 70 years * Men or women * With multiple sclerosis since 2 and 25 years * Affiliates or beneficiaries of social security scheme * Signed consent For Healthy volunteers: * Aged ≥ 18 and ≤ 70 years * Men or women * Matched in accordance with age, sex and level of physical activity Exclusion Criteria: For Patients and Healthy volunteers: * High heart rate resting * Blood pressure \> 144/94 mmHg * Recent adjustment of drug or drug can have an impact on fatigue or stimulant for fatigue * Taking neuroactive substances that can alter corticospinal excitability * Contraindication at application magnetic field * Contraindication at Magnetic Resonance Imaging (MRI) * Currently participating in a structured exercise program * Pregnant For Patients only: * Spasticity or cerebellar ataxia * Abnormal range of motion (toe and/or ankle) * Musculoskeletal injuries that impedes pedaling * Appearance of symptoms of multiple sclerosis in the 90 days preceding the study For Healthy volunteers: \- Neurological diseases, cardiovascular, musculoskeletal