Feasibility and efficacy of peak-velocity interval training vs. moderate-intensity walking training in people with multiple sclerosis with severe fatigue and walking impairment: A pilot randomized controlled trial

High-intensity interval training (HIIT) may yield greater improvements in walking and fatigue for people with multiple sclerosis (MS) than moderate-intensity, continuous training (MICT). This pilot project established the feasibility of peak velocity interval walking training (PVIT, a novel form of HIIT) in people with MS who had elevated fatigue and walking dysfunction and determined initial efficacy on fitness, walking, fatigue, and cognition.

Twelve people with MS [49.3 (7.4) years of age; 9 female; 1-34 years post diagnosis; Fatigue Severity Scale Score >4; Patient-Determined Disease Steps score 3-6] were randomly assigned into PVIT (n = 7) or MICT (n = 5) and completed 12 sessions of training up to 40 min. Feasibility was measured throughout as rates of recruitment, randomization, retention, adherence, and compliance. Pre- and post-assessments included peak oxygen consumption, walking performance, fatigue severity, and cognition.

All participants who enrolled were successfully randomized and completed all sessions (100 % retention) with no adverse events. Adherence was high (86 %) as was intensity compliance (100 %) and did not differ between groups. PVIT resulted in greater walking velocity (relative to maximal overground velocity, 95 % vs. 70 %) and heart rate reserve (93 % vs. 55 %) than MICT. Peak oxygen consumption improved more in the PVIT than MICT condition (14 % vs. 1 % improvement, p < 0.05).

Initial results suggest that PVIT as a form of HIIT is safe, feasible, and may improve aerobic fitness more than MICT in people with MS who have elevated fatigue and impaired walking function.

ClinicalTrials.gov: NCT06264336.