Systematically-Developed Pilot Randomized Controlled Trial of Exercise and Cognition in Persons with Multiple Sclerosis
Objectives: The present pilot study adopted a single-blind randomized controlled trial (RCT) design and is the first to examine the effect of a systematically-developed progressive treadmill walking exercise training intervention on measures of CPS among fully-ambulatory persons with MS.
Methods: 10 fully-ambulatory females with relapsing-remitting MS were randomly assigned into exercise training intervention or waitlist control conditions. The intervention condition involved 3-months of supervised, progressive chronic treadmill walking exercise training that was designed based on pilot work and American College of Sports Medicine guidelines. Participants underwent measures of cardiorespiratory fitness (VO2peak) and CPS before and after the 3-month period; all baseline and follow-up assessments were performed by blinded assessors.
Results: Overall, there were large intervention effects on VO2peak (d=1.08) such that persons who underwent the treadmill walking exercise demonstrated a 14% improvement in cardiorespiratory fitness, whereas there was minimal change for those in the control condition. There further were large effects on Symbol Digit Modalities Test (SDMT) performance (d=0.95) such that persons who underwent treadmill walking exercise training demonstrated a 3-point increase in SDMT scores, whereas those who underwent the waitlist control condition demonstrated a 3-point decrease in SDMT scores. Importantly, changes in VO2peak were significantly associated with changes in SDMT scores (r=.60) such that improved cardiorespiratory fitness was moderately-to-strongly associated with improvements in CPS.
Conclusions: This small pilot RCT provides exciting proof-of-concept data supporting progressive treadmill walking exercise training for potentially improving cardiorespiratory fitness and CPS over time in fully-ambulatory persons with MS, and that improving cardiorespiratory fitness is seemingly a mechanism for improved CPS in this population.