Cognitive Impairment Impacts Exercise Effects on Cognition in Multiple Sclerosis.

Area of Science:

• Neurology
• Exercise Physiology
• Rehabilitation Science

Background:

• Exercise training offers significant cognitive benefits for individuals with multiple sclerosis (pwMS).
• High-intensity interval training (HIIT) may yield superior improvements in physical fitness and cognition compared to moderate continuous exercise.

Purpose of the Study:

• To compare the effects of 3-week HIIT versus moderate continuous exercise on cognitive performance and cardiorespiratory fitness in pwMS.
• To investigate if baseline cognitive status influences the effectiveness of these exercise interventions in pwMS.

Main Methods:

• Seventy-five pwMS were randomized into either a HIIT group (5 intervals at 95-100% HRmax) or a moderate continuous exercise control group (CG) (24 min at 65% HRmax), both training 3x/week.
• Cognitive performance was assessed pre- and post-intervention using the Brief International Cognitive Assessment for MS (BICAMS).
• Analyses included ANCOVA for overall effects and MANOVA for subgroup analyses based on baseline cognitive status (intact vs. impaired).

Main Results:

• Overall analysis showed significant improvements in processing speed, verbal learning, and cardiorespiratory fitness (VO2peak, power output) over time.
• A significant time*group interaction was found for relative power output.
• Subgroup analysis revealed a significant main effect of cognitive status, with pwMS having impaired cognition demonstrating significantly greater improvements in verbal learning following the intervention.

Conclusions:

• Both HIIT and moderate continuous exercise can enhance cognitive function and cardiorespiratory fitness in pwMS.
• Individuals with pre-existing cognitive impairments may experience more substantial benefits in verbal learning from these exercise programs.
• Further large-scale, randomized controlled trials are warranted, using cognitive performance as the primary endpoint and stratifying participants by baseline cognitive status.