This is a 1-arm study with an intervention condition based on the COM-B model

1. The newsletters will provide the knowledge, skills, resources, and strategies for promoting physical activity in persons newly diagnosed with MS. These newsletters will be released seven times during the program. The first three newsletters will be released weekly, and the last four will be released every other week.
2. The one-on-one video coaching chats with participants will be conducted via Zoom, which consist of discussion and elaboration of newsletters content, supportive accountability, feedback and encouragement on behavior change. The chats further provide social persuasion for promoting behavior change. The chats are semi-scripted and individualized interventions (~15 - 30 minutes/chat). The chats will occur seven times during the week when a newsletter is delivered.
3. The intervention includes a pedometer (NL-800 pedometer), a logbook, and a calendar for tracking daily step counts, planning of physical activity, setting goals, and monitoring progress over the program.

Process assesses participant recruitment, retention, and adherence i. Recruitment and refusal rates ii. Retention, attrition, and adherence rates to study procedures

We will assess the resources required for the study.

Management assesses data management.

Overall safety will be assessed through the number of adverse events.

Physical activity will be assessed using an ActiGraph accelerometer. Participants will wear an accelerometer on a belt around their waist during the waking hours of a 7 day period. Participants will complete this at baseline and 12 weeks

Physical activity will be assessed using the Godin Leisure-Time Exercise Questionnaire. Participants will complete this questionnaire at baseline and 12 weeks.

Self report measures of fatigue will be assessed through the Fatigue Severity Scale. Participants will complete this questionnaire at baseline and 12 weeks