Cooling During Inpatient Rehabilitation in Persons With MS

This study has a prospective randomized controlled crossover trial design. During the inpatient stay in the rehabilitation clinic Valens, included participants will be randomized into the following two groups: persons with Multiple Sclerosis will either perform 1) first one week of cooling during intensive active training sessions followed by one week of no cooling during intensive active training sessions, or 2) first one week of no cooling during intensive active training sessions followed by one week of cooling during intensive active training sessions. There is a three-day washout period between the two periods/weeks. This design was chosen to allow all participants to receive the intervention (i.e. the cooling vest during intensive active training sessions), and that each participant is his/her own control to minimize inter-individual variability. The investigators hypothesize that one week of cooling during intensive active training sessions prevents an exercise-induced increase in state fatigue, compared to one week without cooling during the same intensive active training sessions, during the three-week inpatient rehabilitation stay in pwMS. Experimental period: The experimental period consists of one week of wearing a cooling vest during intensive active training sessions during the inpatient rehabilitation stay. Participants will wear a cooling vest (Inuteq PCM CoolOver 6.5C) on their torso, that, according to the manufacturer's specifications, offers constant cooling for up to 1.5 hours at 6.5 degrees Celsius. Participants are instructed to wear at least a (cotton) shirt under the cooling vest. The following rehabilitation prescriptions are defined as intensive active training sessions: endurance training (ergometer groups), resistance training (machine and bodyweight training), gait training (treadmill training, balance training), and physiotherapy (flexibility, mobility, strength, endurance, balance, walking). In addition, the participants receive their usual multidisciplinary inpatient rehabilitation program. Control period: The control period consists of the multidisciplinary inpatient rehabilitation program without cooling during intensive active training sessions. Multidisciplinary inpatient rehabilitation: The multidisciplinary inpatient rehabilitation program is tailored to the patients' individual needs and includes physiotherapy (flexibility, mobility, strength, endurance, balance, walking), occupational therapy (ability and adaptation training) and, occasionally, speech therapy, neuropsychological training and/or counselling by a physician or social worker. There are six measurement timepoints in this study: * T-1: endpoint assessment at baseline (pre-intervention/control (clinic entry)) * T0: baseline endpoint assessment 1st week of intervention/control * T1: endpoint assessment after week 1 of intervention/control * T2: baseline endpoint assessment 2nd week of intervention/control * T3: endpoint assessment after week 2 of intervention/control * T4: endpoint assessment post-intervention/control (3 weeks after clinic entry) State fatigue (VAS score), walking capacity, functional lower extremity muscle strength, balance, and cognition will be measured at T0, T1, T2, and T3 to investigate the effect of cooling vs. no cooling. Additionally, cardiorespiratory fitness and muscle strength will be measured at T-1 and at T4 i) to determine the training intensity, and ii) to investigate the effect of the inpatient stay on cardiorespiratory fitness and muscle strength. Trait fatigue will additionally be measured with the Fatigue Scale for Motor and Cognitive Functions (FSMC) questionnaire at T-1 and at T4, because i) the FSMC total score is used as an inclusion criterion and as a stratification factor, and ii) to investigate the effect of the inpatient stay on trait fatigue.