A new study published in Nature reveals that cognitive training and aerobic exercise produce distinct, beneficial changes in the brains of healthy older adults. While both activities are good for the aging brain, they work in different ways—cognitive training increases gray matter in specific regions, while exercise strengthens connections between those regions.
The Research
Scientists at the University of Illinois at Urbana-Champaign recruited 144 community-dwelling older adults (average age 69) and randomly assigned them to either a cognitive training group, an aerobic exercise group, or a control group. Over 12 weeks, the cognitive training group practiced tasks designed to improve memory and reasoning, while the aerobic exercise group walked or jogged for 30 minutes three times per week. Using MRI scans before and after the intervention, the team measured changes in gray matter volume and inter-regional covariance—a measure of how different brain regions work together.
The results, published in Scientific Reports (a Nature journal) in 2025, show that cognitive training led to increased gray matter volume in the prefrontal cortex and hippocampus—regions critical for decision-making and memory. Aerobic exercise, on the other hand, did not significantly increase gray matter volume but instead enhanced inter-regional covariance, meaning it strengthened the functional connections between brain areas. The control group showed no significant changes.
These findings suggest that cognitive training acts like a "volume knob" for specific brain areas, while aerobic exercise acts like a "Wi-Fi booster" for communication between regions.
Why It Matters
This study is important because it clarifies that different types of mental and physical activities benefit the brain in complementary ways. For older adults concerned about cognitive decline, the takeaway is clear: combining both cognitive training and aerobic exercise may provide a more complete brain health program than either alone. The research also highlights that even in later life, the brain remains plastic and responsive to training.
What You Can Do
To apply this research, aim for a balanced routine: 30 minutes of moderate aerobic exercise (like brisk walking) three times per week, plus 15–20 minutes of cognitive training (such as puzzles, memory games, or learning a new skill) on most days. As the study shows, the specific type of training matters, so choose targeted cognitive tasks rather than passive activities like TV.
Source: Google News: IQ & cognition
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