In this study, we are aiming to systematically review the literature on the effect of HIIT on MS patients as improving physical performance, cognitive function, aerobic fitness and muscle strength. This could help guide the development of standardized clinical guidelines and direct clinical decision making by the physical therapists whether to implement this type of exercises or not.

Multiple sclerosis patients have considerably negative effects on the community and the national and international economy. Chronic symptoms of MS such as fatigue, cognitive impairments, emotional burden and diminished physical functioning considerably affect the daily lives of people with MS and may interfere with social and quality of life factors as friendships, family relationships and occupational status. HIIT has induced significant improvements in physiological conditioning in healthy and clinical populations, and might be appropriate for persons with MS. Recently, several RCTs have been published evaluating the effect of HIIT on MS patients. Consequently, this study will systematically review all these recent literature to direct the physiotherapists whether to implement this type of exercises or not.

Inclusion Criteria:

• Studies: English full texts of RCTs only, Participants: multiple sclerosis patients with age from (20-50) years old irrespectively of sex, subtype of MS, race, diagnostic criteria, community or onset of the disease, Intervention: HIIT, any comparator.

Exclusion Criteria:

• Studies other than English full text RCTs, non adults younger than 20 years and older than 50 years, populations other than multiple sclerosis.

a protocol about the effect of high intensity interval training in patients with multiple sclerosis: systematic review

the studies mask the participants and they randomly divided into 2 groups then the care provider is masked too not to choose specific participant for specific intervention then the outcome assessor is masked to document the outcomes with fair then the investigator is masked too to document results honestly without being motivated towards the intervention.