Abstract
Older adults show both age-related decreases in resting state functional connectivity and diminished sensorimotor function. Exercise has emerged as an intervention that may mitigate or even reverse these age-related declines. Here we sought to understand whether exercise impacts resting state functional connectivity, and motor acquisition and learning in older adults. Forty-two healthy older adults rested or completed 3 sets of high-intensity interval exercise (3 minutes at 75% maximal power output and 3 minutes light intensity) for a total of 23 minutes, then immediately practiced a complex, implicit motor task with their non-dominant hand across five separate sessions. Participants completed resting stage functional MRI before the first and after the fifth day of practice; they also returned 24-hours and 35-days following their fifth day of practice to complete short- and long-term retention tests to assess motor learning. 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. There was no motor learning advantage for the exercise group; both rest and exercise groups demonstrated motor learning as measured at the short- and long-term retention tests. Our data suggest that exercise paired with a challenging implicit motor learning task in older adults can augment resting state functional connectivity without enhancing behaviour beyond that stimulated by skilled motor practice.
Significance statement Aging is accompanied by significant declines in the capacity for motor learning and changes in resting state functional connectivity; the net result is poor motor performance. Here, we show that five separate bouts of exercise paired with skilled motor practice strengthens resting state networks in brain regions that are susceptible to declines in older adults without affecting motor acquisition or learning. Overall, our results suggest that exercise may be effective in reducing age-related disruptions to resting state networks but not in enhancing motor learning beyond that stimulated by practice alone in older adults.
Competing Interest Statement
The authors have declared no competing interest.
Footnotes
The authors declare no competing financial interests.