## 4 Discussion
### Core Training for Gait and Exercise Capacity  
Gait and exercise capacity were assessed using various tools. Compared to the control group, most studies reported significant improvements in the experimental group for both outcomes.  
Gait was assessed using different tests. The T25 FW test reported improvements in two out of three studies, although only one reported a difference between groups. This test is considered the gold standard for assessing ambulation in people with MS [41]. The most frequently used test was the TUG, which reported improvements in four out of five studies; however, only two reported significant differences between groups. The TUG test is a reliable and widely used tool for assessing gait in people with MS [41,42]. The MSWS was the second most commonly used tool for evaluating gait, showing improvements in three out of five studies. As a patient-reported outcome, the MSWS is a highly recommended scale because it shows the patient's perspective, does not require clinical resources, and has been shown to correlate the distance walked in the 6 MWT [43]. The 10 MTW showed improvements in two of the three articles in which it was used. It is widely used to assess gait speed in MS [44], as well as in other pathologies, such as stroke [45]. Additionally, the SSST was used in one study, which reported significant improvement. This test has shown reliability in the stroke [46,47] and MS populations [48].  
The differences observed in the SSST, 6 MWT, and 2 MWT were clinically significant, exceeding the minimal clinically important difference (MCID) [49, 50, 51]. For the 25 FWT and 10 MWT, clinical significance varied, as not all the studies surpassed the MCID threshold [52,53]. Although statistically significant differences were observed for the TUG and MSWS, these did not meet the MCID, thus limiting clinical relevance [54,55].  
There is a consensus that exercise-based interventions are beneficial in people with MS [55; 56; 57; 58; 59; 60; 61]. Despite the well-established benefits of physical exercise on functional performance in this population, it remains unclear whether one type of exercise is superior to others. One study attempted to determine whether differences exist among various exercise modalities but found no significant differences [62]. A recent systematic review and meta-analysis assessing the effects of core stability training on balance in people with MS concluded that six to ten weeks of training is an effective therapeutic strategy for balance improvement [15]. However, to our knowledge, this is the first systematic review to specifically evaluate the effects of core-focused interventions on gait and exercise capacity in people with MS. Previous systematic reviews [57; 58; 59; 60; 61; 62] highlighted similar concerns, including the need for high-quality randomized controlled trials, standardized measurement tools to enhance research quality, and detailed descriptions of interventions to ensure replicability.  
The studies included in this review consistently emphasize the need for further research with larger sample sizes and well-defined parameters for intensity, duration, and frequency to facilitate the development of clinical practice guidelines and validate the efficacy of interventions.