Feasibility of a High-intensity Interval Training Program in Persons With Multiple Sclerosis Who Have Walking Disability

Participant recruitment, retention, and adherence rates will be recorded.

Staff training, communication, recruitment, and intervention time will be recorded.

Monetary research costs will be recorded.

Time from submission of Institutional Review Board application to approval will be recorded. All time spent collecting, entering, and checking data will be recorded.

Participants' experience, burden, and perceptions will be assessed via a short survey at the end of the 12 weeks.

Adverse events, serious adverse events, and clinical emergencies will be recorded.

Participants will complete a standardized graded maximal exercise step on a recumbent stepper. The highest recorded 30-second volume of oxygen consumption (VO2) value will be recorded as VO2peak, expressed in mL/kg/min, when at least 1 of the following criteria are satisfied: (1) respiratory exchange ratio 1.10 or greater; (2) peak heart rate within 10 beats per minute of age-predicted maximum(i.e., 220-age); or (3) ratings of perceived exertion of 7 or greater.

Participants will walk for a total of 6 minutes along a single course 75-feet in length with two, 180-degree turns. Total distance travelled (ft) will be recorded.

Participants will be instructed to walk as fast as possible along a 25-foot path. Participants time recorded as walking speed (ft/s) will be collected twice. The average of the two trials will be reported.

Participants will be asked to wear an accelerometer for 7 consecutive days for a minimum of 10 hours of wear time. Using the accelerometer software, sedentary, light, and moderate-to-vigorous counts of physical activity will be generated based on disability status.

Participants will complete the oral version of the Symbol Digit Modalities Test, the first five recall trials of the California Verbal Learning Test-2, and the first three recall trials of the Brief Visuospatial Memory Test-Revised. The Symbol Digit Modalities Test reports the correct number of responses with a maximum score of 110. The California Verbal Learning test reports the total number of correct words identified over five trials, with a maximum score of 90. The Brief Visuospatial Memory Test-Revised reports the total raw score across the three trials, with a maximum score of 36.

Participants are instructed to pick up pegs and place them one at a time into one of nine holes as fast as possible and then to remove the pegs, one at a time, with the same hand. The time (s) to complete this activity will be recorded and averaged on two trials for the dominant hand and then the non-dominant hand.

Participants will be asked to complete the Fatigue Severity Scale, which is a self-report measure comprised of 9 items that assess the severity of fatigue symptoms. This Likert scale ranges from 1 (strongly disagree) and 7 (strongly agree) and measures the degree of fatigue severity over the past week. All items will be summed for a final score with higher scores indicating greater fatigue severity and a maximum score of 63.

Depressive symptoms will be measured by the Depression sub-scale of the Hospital Anxiety and Depression Scale (HADS-D). The HADS-D includes 7 items that measure depression and are rated on a 4-point scale ranging between 0 (not at all) to 3 (most of the time). Positively worded items are reverse-scored and then added with negatively worded items to create a total sum with a maximum value of 21.