Improved cognition after high-intensity exercise paired with motor practice in individuals with stroke and older adults: A randomized controlled trial

Introduction Stroke is a leading cause of long-term disability resulting in cognitive and motor impairments. Exercise may improve cognition and motor function. We paired multiple bouts of high-intensity interval training (HIIT) exercise with motor practice to positively affect cognitive and motor function after stroke and age-matched controls. Methods Using a randomized controlled parallel group design, 31 individuals with chronic stroke and 41 older adult controls were randomized to either 23 minutes of HIIT exercise or rest prior to completing motor task practice using their paretic/non-dominant arm across five days. Primary outcomes were reaction time and motor function. Assessors were blinded to the intervention group. Trail Making Test-A and B (TMT-A, TMT-B), and object hit and avoid (OHA) were used to assess processing speed and inhibitory control. Results All participants showed evidence of motor learning; HIIT exercise did not confer an additional benefit. For stroke participants, motor function ( p = .047), but not motor impairment, improved. The stroke exercise group displayed significant reductions in TMT-A completion time ( p = .026). Exercise with motor practice also led to a reduced number of distractors hit ( p = .035) in the OHA task for both participant groups. There were no adverse events. Conclusions Five days of HIIT exercise paired with motor practice led to improved processing speed for individuals with stroke. Both participant, exercise groups showed improved visuospatial skills and inhibitory control. Together, HIIT exercise paired with motor practice appears to be a safe and effective means of enhancing cognitive-motor skills after stroke and in older adults. Trial Registry [ClinicalTrials.gov][1], ID: [NCT02980796][2] Trial registry name The Influence of Exercise on Neuroplasticity and Motor Learning After Stroke (EX-ML3) ### Competing Interest Statement The authors have declared no competing interest. ### Clinical Trial NCT02980796 ### Funding Statement This work was funded by the Canadian Institutes of Health Research (PI L.A.B., PJT-148535). JWA, JF, BC and BL are funded by a Canadian Institutes of Health Research (CIHR) fellowships. JN and JWA were also funded by the Michael Smith Foundation for Health Research. ### Author Declarations I confirm all relevant ethical guidelines have been followed, and any necessary IRB and/or ethics committee approvals have been obtained. Yes The details of the IRB/oversight body that provided approval or exemption for the research described are given below: This study was approved by the University of British Columbia Ethics Committee (Clinical Research Ethics Board #H16-01945) and all participants read and signed a consent form prior to any experimental protocols. I confirm that all necessary patient/participant consent has been obtained and the appropriate institutional forms have been archived, and that any patient/participant/sample identifiers included were not known to anyone (e.g., hospital staff, patients or participants themselves) outside the research group so cannot be used to identify individuals. Yes I understand that all clinical trials and any other prospective interventional studies must be registered with an ICMJE-approved registry, such as ClinicalTrials.gov. I confirm that any such study reported in the manuscript has been registered and the trial registration ID is provided (note: if posting a prospective study registered retrospectively, please provide a statement in the trial ID field explaining why the study was not registered in advance). Yes I have followed all appropriate research reporting guidelines, such as any relevant EQUATOR Network research reporting checklist(s) and other pertinent material, if applicable. Yes All data will be available from the corresponding author upon reasonable request. [1]: http://ClinicalTrials.gov [2]: /lookup/external-ref?link_type=CLINTRIALGOV&access_num=NCT02980796&atom=%2Fmedrxiv%2Fearly%2F2023%2F08%2F13%2F2023.02.09.23285669.atom