Eccentric Cycling in Multiple Sclerosis Rehabilitation

Our study will focus on multiple sclerosis. For each pathology included, a "control" group will consist of patients undergoing a traditional rehabilitation program combined with a concentric cycling session. An experimental group ("eccentric rehabilitation") will consist of patients enrolled in an eccentric ergocycle training protocol paired with standard rehabilitation. In practice, a portion of the classical rehabilitation program will be replaced by either concentric or eccentric cycling, for a maximum duration of 30 minutes. Based on a preliminary study conducted in healthy subjects, a review of the existing literature, and a sample size calculation performed by the Biostatistics Department of the University Hospital of Liège, investigators aim to recruit 60 to 80 subjects per pathology (details in the appendix). Participation of pregnant women is permitted.

Type of Study

This is a prospective interventional study conducted longitudinally, with all subjects evaluated over the same time period (2025-2027). The study will take place at the Sart-Tilman sites (Blanc-Gravier, Exercise Physiology Unit) or at the CNRF in Fraiture-en-Condroz, depending on participant preference.

Neurological Pathologies Inclusion criteria

Participants must:

present with one of the following neurological disorders: Parkinson's disease or multiple sclerosis.

I. Eccentric Rehabilitation Program

Given the increasing clinical interest in eccentric contraction modalities for chronic diseases, a semi-recumbent eccentric ergometer has been specifically designed for clinical use. Patient installation on this device is safe and easily achievable, and the semi-recumbent position provides additional comfort during exercise. The ergometer allows secure workload control via visual feedback powered by dedicated software. The device can be transported between sites (Sart-Tilman - Fraiture - Esneux).

Experimental Protocol

This experimental study aims to establish and compare the effects of an eccentric cycling training protocol versus a traditional concentric cycling protocol performed on an ergometric bicycle. Subjects will be randomly allocated (stratified by sex and disease stage) into one of the two experimental groups. Randomization will be conducted by Mr. Benoît Vandenbroeck after encoding the relevant data in a table and assigning subjects within each stratum using random distribution.

Participants will undergo a 2-week evaluation period followed by a 12-week training program consisting of two sessions per week, for a total of 28 sessions. Sessions will take place either at the Neurological and Functional Rehabilitation Center in Fraiture-en-Condroz (CNRF) or at Blanc-Gravier (Sart-Tilman), according to participant preference. Training sessions (eccentric or concentric) will last a maximum of 30 minutes. For participants already enrolled in a rehabilitation program at the CNRF, part of their traditional session will be replaced by the cycling training.

The unusual nature of eccentric training may induce mild delayed-onset muscle soreness (DOMS), including pain and stiffness, appearing 24-48 hours after exercise. These symptoms are transient, and symptomatic treatments (analgesics, stretching, ice) are not permitted.

Multiple variables will be assessed before, during, and after the intervention period to quantify potential effects of each training protocol and allow direct comparison.

Description of Study Phases

The study consists of 5 phases over a 12-week period (see appendix):

Phase 0: Baseline Testing

Measurements will be collected 5-7 days before and 7-14 days after the training period to monitor longitudinal changes and evaluate the impact of the protocols on body composition and functional capacity.

Eccentric Ergocycle Training Protocol Phase 1: Familiarization (4 weeks)

Two sessions per week for four weeks. The main objective is to familiarize subjects with eccentric cycling and its specific neuromuscular demands, thus limiting potential muscle damage. Duration and intensity will gradually increase. To progress to the training phase, subjects must maintain an average power output within ±10% of their target theoretical power during the final familiarization session. If needed, one to two additional weeks of familiarization may be added. Beyond this point, participants unable to meet the criteria will be withdrawn from the study.

Phase 2: Training (Part 1 - 4 weeks)

These four weeks establish the first phase of training, with predefined duration and intensity levels.

Phase 3: Training (Part 2 - 4 weeks)

An additional four weeks are included, based on evidence showing greater benefits after 8-12 weeks of training. Intensity will be increased during this phase.

Throughout the 12-week training period, temporal progression and identification of potential physiological adaptations will be monitored.

Phase 4: Final Testing

Participants will return to the laboratory twice to repeat the baseline assessments. These tests will be performed 7-10 days after the final training session to ensure adequate muscle recovery.

Inclusion criteria

• Diagnosis of multiple sclerosis
• Multiple sclerosis: EDSS score < 7
• Age under 75 years
• Stable disease state
• Written medical clearance authorizing participation
• Legal adult status
• Written informed consent, with demonstrated understanding of the consent form (via a few specific questions)
• Ability to mobilize independently (e.g., transfers, walking)

Exclusion criteria

• One or more contraindications to physical activity
• Significant comorbidities
• Current hospitalization or undergoing changes in medication
• Active flare-up