Each patient was recommended a conventional exercise programme tailored to their needs. These included exercises aimed at strengthening the lower extremities and torso, exercises targeting patients' balance and walking problems (progressing from hard to soft surfaces, from eyes open to eyes closed, and from a wide support base to a narrow support base), walking training exercises (ceremonial walking, walking with reduced support area, sideways walking exercises), and exercises targeting coordination problems (Frenkel coordination exercises from sitting and supine positions, depending on the patient's condition).

The aerobic exercise programme was implemented over a total of 8 weeks, with two sessions per week, using a treadmill under the supervision of a specialist physiotherapist. Patients' functional capacities were determined by estimating VO2 peak using walking distance, heart rate, and blood pressure measured at 6 DYT. During the aerobic exercise programme, patients' heart rates and oxygen saturation levels were monitored using a pulse oximeter, and care was taken to ensure that the Borg Scale value perceived by patients was between 11 and 14. After the aerobic exercise programme ended, heart rate, blood pressure, and Borg Scale were monitored for at least 5 minutes until they returned to baseline values. The session duration was planned in accordance with the literature, consisting of three phases: a warm-up phase, a loading phase, and a cool-down phase, lasting a minimum of 30 minutes and a maximum of 40 minutes.

The aerobic exercise programme was implemented over a total of 8 weeks, with two sessions per week, using a treadmill under the supervision of a specialist physiotherapist. Patients' functional capacities were determined by estimating VO2 peak using walking distance, heart rate, and blood pressure measured at 6 DYT. During the aerobic exercise programme, patients' heart rates and oxygen saturation levels were monitored using a pulse oximeter, and care was taken to ensure that the Borg Scale value perceived by patients was between 11 and 14. After the aerobic exercise programme ended, heart rate, blood pressure, and Borg Scale were monitored for at least 5 minutes until they returned to baseline values. The session duration was planned in accordance with the literature, consisting of three phases: a warm-up phase, a loading phase, and a cool-down phase, lasting a minimum of 30 minutes and a maximum of 40 minutes.

The primary outcome of the study is to determine clinical progression in individuals with MS. Functional mobility, walking capacity, and upper extremity functions were measured to assess clinical progression. To this end, the 6-Minute Walk Test (6MWT), 9-Hole Peg Test (9HPT), and Timed Up and Go Test (TUG) were administered. In the E group, a significant decrease was observed in dominant and non-dominant DDPT times and TWT time, while a significant increase was observed in 6WWT distance (p<0.001). No significant change was observed in these parameters in the control group (p>0.05). In the intergroup comparison, the improvements in the Exercise Group were found to be statistically significantly more pronounced than in the control group (p<0.001). These findings indicate that an eight-week aerobic exercise programme has a positive effect on clinical progression markers in individuals with MS.

Secondary outcomes are biomarkers reflecting NVU function. Serum NfL, serum VEGF-a, and serum GFAP were measured as NVU markers. Measurements were performed using the ELISA method with blood samples taken in the morning after all participants had fasted.

Secondary outcome analyses revealed no significant change in NfL, VEGF-a, and GFAP levels in either within-group or between-group comparisons (p>0.05). This finding indicates that the eight-week aerobic exercise programme did not have a significant effect on NVU biomarkers.