Aerobic Exercise for People with Advanced Multiple Sclerosis: Challenges to Prescription and Considerations for Intervention Development

Abstract

Exercise is an important component of comprehensive disease management in multiple sclerosis (MS); however, existing evidence is largely derived from individuals with mild-to-moderate disability. Consequently, the role of exercise for people with advanced MS (i.e., wheelchair users) is not well understood, limiting the development of evidence-based exercise recommendations for this MS subgroup. This thesis addressed these gaps through two complementary studies. The first study examined the relationships between commonly used exercise intensity indicators (i.e., heart rate [HR], work rate [WR], and rating of perceived exertion [RPE]), as well as the agreement between age-predicted and measured maximal HR during an incremental exercise test in people with advanced MS. Results indicate that WR correlated strongly with RPE (ρ = 0.53; p < 0.001) and moderately with HR (ρ = 0.34; p < 0.001), while HR and RPE were not correlated (ρ = 0.10; p = 0.23). Age-predicted and measured maximal HR showed poor agreement using equations derived from non-clinical populations (bias = 40–45 bpm), but strong agreement with an equation derived from a cardiac population taking beta-blockers (bias = 2 bpm). These findings suggest that exercise intensity prescription in advanced MS should use multiple indicators, given the lack of consistent relationships between commonly used intensity measures. Additionally, standard approaches to exercise prescription may overestimate maximal HR, highlighting the need for disability-specific strategies. The second study presents a protocol to evaluate the feasibility of a 12-week aerobic exercise training intervention for people with advanced MS. Feasibility of the intervention will be assessed across domains including process, resources, management, safety, acceptability, and outcomes. Findings will inform a future large-scale trial aimed at evaluating the efficacy of aerobic exercise training. Collectively, this thesis advances understanding of exercise prescription and intervention design for people with advanced MS. This work may support the development of evidence-based exercise guidelines for this MS subgroup, with potential to increase exercise engagement and improve health outcomes.