The recruitment plan is to distribute study announcements through multiple avenues, such as contacting previous research participants with MS via phone, distributing flyers and brochures highlighting

this research opportunity, sending programme information Imatinib Mesylate via MS-specific listsrvs, and posting web-based advertisements (eg, the website of the Greater Illinois chapter of the National Multiple Sclerosis Society). Study and recruitment information will also be distributed at various MS support meetings. Finally, we plan to utilise a large local hospital as a recruitment source. All ads will encourage interested participants to contact the research coordinator by phone or email for more detailed study information. A toll-free phone number will be available for people outside the local calling area and a pre-screening telephone script will be used to determine eligibility prior to scheduling testing appointments. Eligibility criteria Inclusion criteria for participation will be: a definite diagnosis of MS that is confirmed in writing by the participant’s neurologist or primary physician; being sedentary or physically inactive (ie, not regularly engaging in physical activities of ≥30 min on more than 2 days of the week during the past 6 months); aged 50 years or older;

fluent in English; ambulatory with minimal assistance (ie, walk independently or with an assistive walking device); the provision of medical clearance for participation in a physical activity programme by participants’ physicians; and an Expanded Disability Status Scale (EDSS) score of less than 6.5 (ie, constant bilateral assistance).26 The EDSS cut-off was selected for concerns with patient safety (ie, falls). Additionally, during the pre-screening phone call, cognitive impairment will be assessed by using the Modified Telephone Interview for Cognitive Status (ie, TICS-M) questionnaire to assess cognitive status.27 Potential subjects who score below 21

(of 39) on the TICS-M will be excluded from the trial. Potential participants who meet eligibility criteria and successfully pass the pre-screening will receive a letter inviting them to participate, a document requesting authorisation to contact their physician for clearance GSK-3 to participate, an informed consent document (including an additional copy for their personal records), and a self-addressed stamped envelope to return these documents. The study’s research coordinator will be responsible for managing these mailings. On receipt of the signed documents, the research coordinator will file the informed consent form and contact the physician for the necessary clearance.