Comparison of Vigorous Versus Low Intensity Cool Room Treadmill Training in People With Multiple Sclerosis

Comparison of Vigorous Versus Low Intensity Cool Room Treadmill Training in People With Multiple Sclerosis

Training to Restore Walking and Promote Nervous System Repair in Multiple Sclerosis: RCT to Determine the Importance of Intensity

New research in animal models of MS suggests that greater training intensity is required to restore lost functions. We have developed and tested vigorous intensity cool room treadmill training that people with MS who have fatigue and heat-sensitivity can tolerate. This study will focus on the appropriate dosage of training.

Our previous research showed that vigorous aerobic training in a room cooled to 16°C can improve walking and measures of brain plasticity among people with MS related walking disability, especially in those who had fatigue and heat sensitivity. As a next step, we will compare our novel vigorous intensity cool room treadmill training to low intensity cool room treadmill walking and determine whether intensity is important in order to improve brain repair and restore walking among people with MS. Our first objective is to compare the effects of 12 weeks of vigorous versus low intensity training on walking. Our second objective is to determine whether treadmill training alters indicators of brain repair. We hypothesize that the cool room vigorous training will result in greater increases in walking and less fatigue, which will be sustained at follow-up. We also hypothesize that improvements will align with less brain inhibition (shortened CSP measured using Transcranial Magnetic Stimulation) and greater upregulation of the neurotrophin IGF-1.

The outcome assessor will be blinded to group allocation, and will not be involved in conducting the training intervention.

Exercise will be performed on a treadmill using an overhead harness for safety in a temperature controlled-room at 16°C with 1:1 supervision. The high intensity group will maintain vigorous intensity with a target workload >60% of heart rate reserve for 30 min (plus 5min warm up and 5min cool down) while the low-intensity group will walk at mild intensity (<40% heart rate reserve) for the same duration. Heart rate, blood pressure, and rating of perceived exertion will be recorded throughout to monitor for potential adverse events and to ensure that target training zone heart rates are maintained. The intervention is 3 times per week for 12 weeks, with a 3-month run-in observational period to confirm disease stability, and 3-month follow-up to determine the sustainability of effects.

Walkway outputs include step length and width (cm), double support time (%), symmetry (ratio between affected and less-affected sides)

The Multiple Sclerosis Impact Scale-29 provides physical and psychological sub-scales. Using a Likert scale, participants indicate the degree to which problems, such as 'moving about' and 'balance' affect them from 'not at all' to 'extremely'.

A 9-item questionnaire, which assesses the severity of fatigue with items scored on a 7-point scale, '1 = strongly disagree' and '7 = strongly agree'. The minimum and maximum score possible are 9 and 63 respectively. Another reporting method is the mean of all scores from all 9-items, with minimum and maximum score possible being 1 and 7 respectively.

A self-reported rating scale of severity of mood symptoms ranging from 0-21 with higher score indicating more symptoms.

Measures overall cognitive function with score ranging from 0 to 30 with higher scores indicating higher executive function

Standardized protocol recommended by the Canadian Dementia Imaging Group (https://www.cdip-pcid.ca/) which includes T1 and T2-weighted structural images, diffusion tensor imaging, and resting state connectivity.

Inclusion Criteria: people with a confirmed diagnosis of relapsing-remitting or progressive MS older than 18 and less than 70 years of age able to walk at least 10 meters with use of walking aids (Expanded Disability Status Scale (EDSS) <7.0) must be stable without relapse for at least 90 days Exclusion Criteria: currently attending physical rehabilitation functional community ambulators (gait speed>120 cm/s) a relapse of MS