Physical activity may mitigate sleep-related cognitive deficits in older adults: Findings from the IGNITE study

Poor sleep is commonly associated with poorer cognition in older adults. Unfortunately, effective sleep improvement therapies for older adults are limited in their accessibility and have shown only subtle effects on cognition. Physical activity, however, is associated with better cognition in older adults and may compensate for cognitive deficits related to poor sleep. This study examined whether greater engagement in physical activity moderates the association between sleep and cognitive function in older adults.

We utilized baseline data from the Investigating Gains in Neurocognition in an Intervention Trial of Exercise (IGNITE) study. Cognitively unimpaired older adults (n = 589, mean age ± SD: 69.8 ± 3.7, 70% female) underwent a comprehensive cognitive assessment. Sleep was measured via the Pittsburgh Sleep Quality Index (PSQI), and both sleep and physical activity were measured using 24-h actigraphy for 7 days.

Moderate-to-vigorous physical activity (MVPA) accumulated in at least 10-min bouts moderated the association between self-reported sleep efficiency and episodic memory, processing speed, executive function (EF)/attentional control, and working memory (β_[range] = -0.10 to -0.17, all p < 0.05). In addition, light-intensity physical activity moderated the association of actigraphy-measured wake after sleep onset (WASO) with EF/attentional control and processing speed (β_s = 0.10, all p < 0.05). The direction of these results was such that lower sleep efficiency and greater WASO was associated with poorer cognitive performance, but this association was attenuated by engaging in greater amounts of physical activity.

These results support the hypothesis that physical activity may mitigate the association between poor sleep and cognitive deficits in older adulthood. We highlight the need for further longitudinal studies and randomized clinical trials of exercise to further examine these associations. These results suggest that even small amounts of MVPA or light intensity physical activity mitigate the association between poor sleep and cognitive deficits in older adulthood.

Moderate-to-vigorous physical activity moderated the association of self-reported sleep efficiency with cognition.Light physical activity moderated the association of wake after sleep onset with cognition.Physical activity may mitigate sleep-related cognitive deficits in older adults.Further longitudinal studies and randomized controlled trials are needed.