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The effects of acute aerobic exercise on motor skill learning and neurophysiology in healthy older adults

University of British Columbia

Aging is associated with a reduced ability to perform motor tasks, as well as a decreased capacity for neuroplastic change and motor skill learning. Evidence in young healthy adults suggests a single session of aerobic exercise can facilitate motor learning and changes in movement-related neurophysiological circuits. However, we do not know whether these effects extend to healthy older adults. The objectives of the present thesis were to examine whether a single session of moderate-intensity aerobic exercise 1) facilitates motor skill acquisition and consolidation, and 2) modulates motor cortical and intracortical circuitry, in healthy older adults. Twenty-two participants (55-75 years old) completed a maximal exercise stress test at least two days prior to all other sessions. Next, participants practiced a motor sequence task after 20-minutes of moderate-intensity cycling or 20-minutes of seated rest, on separate occasions. To assess motor learning, participants performed the motor task 24 hours later at a no-exercise retention test. On a separate day, neurophysiological measures using transcranial magnetic stimulation were obtained at two time-points prior to and two time-points following an acute bout of moderate-intensity cycling. Performing aerobic exercise immediately prior to task practice did not yield any statistically significant differences in measures of motor skill acquisition or consolidation. However, we observed a non-significant trend towards improvements in motor memory consolidation, such that under the exercise condition there were greater improvements in repeated sequences compared to rest. Additionally, we found that after exercise there was an increase in long-interval intracortical inhibition (LICI), which returned to near baseline levels within 30 minutes post-exercise. Overall, these findings suggest that a single bout of moderate-intensity aerobic exercise transiently modulates GABA-B mediated intracortical inhibition in healthy older adults, however, these exercise-induced neurophysiological effects may not necessarily translate to changes in motor behaviour. This work is the first to investigate the efficacy of an acute bout of aerobic exercise in facilitating motor performance and learning, as well as modulating motor cortical and intracortical circuits, in healthy older adults. Further understanding of how exercise influences motor learning and neurophysiology in the aging brain will be critical for the development of potential rehabilitation strategies. 

Text

2018-05-28

Attribution-NonCommercial-NoDerivatives 4.0 International

http://hdl.handle.net/2429/66135

Rehabilitation Sciences

University of British Columbia

UBCV

http://creativecommons.org/licenses/by-nc-nd/4.0/