Multiple bouts of high-intensity interval exercise reverse age-related functional connectivity disruptions without affecting motor learning in older adults

Brian Greeley,Briana Chau,Jason L Neva,Sarah N Kraeutner,Lara A Boyd,Kristin L Campbell,Christina B Jones

doi:10.1038/s41598-021-96333-4

Abstract

Exercise has emerged as an intervention that may mitigate age-related resting state functional connectivity and sensorimotor decline. Here, 42 healthy older adults rested or completed 3 sets of high-intensity interval exercise for a total of 23 min, then immediately practiced an implicit motor task with their non-dominant hand across five separate sessions. Participants completed resting state functional MRI before the first and after the fifth day of practice; they also returned 24-h and 35-days later to assess short- and long-term retention. Independent component analysis of resting state functional MRI revealed increased connectivity in the frontoparietal, the dorsal attentional, and cerebellar networks in the exercise group relative to the rest group. Seed-based analysis showed strengthened connectivity between the limbic system and right cerebellum, and between the right cerebellum and bilateral middle temporal gyri in the exercise group. There was no motor learning advantage for the exercise group. Our data suggest that exercise paired with an implicit motor learning task in older adults can augment resting state functional connectivity without enhancing behaviour beyond that stimulated by skilled motor practice.

Highlights

Exercise has emerged as an intervention that may mitigate age-related resting state functional connectivity and sensorimotor decline
Data from studies of young adults suggest that exercise can enhance cortical excitability and may improve motor learning
The majority of research investigating the impact of highintensity interval exercise has focused on healthy young individuals; no previous work has considered whether pairing skilled motor practice with high-intensity interval exercise will impact motor learning in older adults

Summary

Introduction

Exercise has emerged as an intervention that may mitigate age-related resting state functional connectivity and sensorimotor decline. 42 healthy older adults rested or completed 3 sets of high-intensity interval exercise for a total of 23 min, immediately practiced an implicit motor task with their non-dominant hand across five separate sessions. Our data suggest that exercise paired with an implicit motor learning task in older adults can augment resting state functional connectivity without enhancing behaviour beyond that stimulated by skilled motor practice. Data from studies of young adults suggest that exercise can enhance cortical excitability and may improve motor learning. As the limbic system is impacted by both c hronic[9,10] and single, 20 min bout of e xercise[11], motor learning tasks that engage these brain regions may be enhanced following exercise. A month of exercise enhances learning along with hippocampal neurogenesis in aged

Methods

Results

Discussion

Conclusion