2. Diagnosed of relapsing remmiting multiple sclerosis
3. Relapse free in the past 30 days
4. Initial confirmation of sexual dysfunction (based on a semi-structured interview on sexual dysfunction diagnostic criteria in DSM-5)
5. Currently in a committed relationship with a partner who does not have a sexual disorder or sexual dysfunction
6. Internet and email access
7. Willingness to complete the questionnaires, wear the pedometer, and undergo randomization
8. Insufficient physical activity \[not meeting current physical activity guidelines based on a health contribution score of less than 14 units from the Godin Leisure-Time Exercise Questionnaire (GLTEQ)\]
9. Ability to ambulate without assistance \[self-report and Patient-Determined Disease Steps (PDDS) score between 0 and 2 (mild ambulatory disability)\]
10. Age between 18 and 45 years
11. English as primary language
\-
You may not be if
1\. Moderate or high risk for contraindications of possible injury or death when undertaking strenous or maximal exercise
