Exercise interventions preserve hippocampal volume: A meta‐analysis

Hippocampal volume is a marker of brain health and is reduced with aging and neurological disease. Exercise may be effective at increasing and preserving hippocampal volume, potentially serving as a treatment for conditions associated with hippocampal atrophy (e.g., dementia). This meta‐analysis aimed to identify whether exercise training has a positive effect on hippocampal volume and how population characteristics and exercise parameters moderate this effect. Studies met the following criteria: (a) controlled trials; (b) interventions of physical exercise; (c) included at least one time‐point of hippocampal volume data before the intervention and one after; (d) assessed hippocampal volume using either manual or automated segmentation algorithms. Animal studies, voxel‐based morphometry analyses, and multi‐modal interventions (e.g., cognitive training or meditation) were excluded. The primary analysis in n = 23 interventions from 22 published studies revealed a significant positive effect of exercise on total hippocampal volume. The overall effect was significant in older samples (65 years of age or older) and in interventions that lasted over 24 weeks and had less than 150 min per week of exercise. These findings suggest that moderate amounts of exercise for interventions greater than 6 months have a positive effect on hippocampal volume including in older populations vulnerable to hippocampal atrophy

Aerobic exercise improves episodic memory in late adulthood: A systematic review and meta-analysis

Background Aerobic exercise remains one of the most promising approaches for enhancing cognitive function in late adulthood, yet its potential positive effects on episodic memory remain poorly understood and a matter of intense debate. Prior meta-analyses have reported minimal improvements in episodic memory following aerobic exercise but have been limited by restrictive inclusion criteria and infrequent examination of exercise parameters. Methods We conducted a meta-analysis of randomized controlled trials to determine if aerobic exercise influences episodic memory in late adulthood (M = 70.82 years) and examine possible moderators. Thirty-six studies met inclusion criteria, representing data from 2750 participants. Results Here we show that aerobic exercise interventions are effective at improving episodic memory (Hedges’g = 0.28; p = 0.002). Subgroup analyses revealed a moderating effect of age (p = 0.027), with a significant effect for studies with a mean age between 55–68 but not 69–85. Mixed-effects analyses demonstrated a positive effect on episodic memory among studies with a high percentage of females (65–100%), participants with normal cognition, studies reporting intensity, studies with a no-contact or nonaerobic physical activity control group, and studies prescribing >3900 total minutes of activity (range 540–8190 min). Conclusions Aerobic exercise positively influences episodic memory among adults ≥55 years without dementia, with larger effects observed among various sample and intervention characteristics—the clearest moderator being age. These results could have far-reaching clinical and public health relevance, highlighting aerobic exercise as an accessible, non-pharmaceutical intervention to improve episodic memory in late adulthood