Abstract
Research suggests that physical activity is related to important health outcomes such as reduced risk for chronic diseases, healthy weight maintenance, better overall physical fitness, and enhanced mental well-being (Warburton & Bredin, 2016). While the general benefits of exercise are well-documented, less is known about how exercise may specifically impact cognitive function and brain health in young adults. The purpose of this research study was to systematically investigate the relationship between physical activity levels, cognitive performance, and brain structure in college students between the ages of 18 to 25.
A sample of 120 college students (60 male, 60 female) between the ages of 18-25 (M = 20.34, SD = 1.76) was recruited from a large midwestern university. Participants were randomly assigned to either an 8-week physical activity intervention group or a no-intervention control group. Intervention participants engaged in aerobic exercise 3 days per week for 30-45 minutes each session. Exercise intensity was gradually increased over the 8 weeks until participants were exercising at 60-75% of their maximum heart rate. Control participants were instructed to maintain their normal activity levels.
Cognitive performance was assessed using a battery of computerized tasks measuring attention, memory, processing speed, and executive function at baseline and post-intervention. Structural brain scans using magnetic resonance imaging (MRI) were also conducted at baseline and post-intervention to examine changes in brain volume of specific regions implicated in cognitive function. These regions included the prefrontal cortex, hippocampus, and basal ganglia. Exercise level was tracked objectively throughout the 8 weeks using wearable accelerometers.
A series of 2 x 2 mixed model ANCOVAs controlling for sex and baseline scores were conducted to examine differences in cognitive performance and brain structure changes between the intervention and control groups from pre- to post-intervention. Results indicated significant group by time interactions for attention, processing speed, prefrontal cortex volume, and hippocampal volume such that the intervention group showed greater improvements compared to controls. No significant differences between groups were found for memory or executive function tasks or basal ganglia volume.
Additional correlational analyses were performed to explore relationships between objective exercise levels recorded by accelerometers and cognitive and brain changes within the intervention group. Moderate to high positive correlations were observed between total minutes of moderate-vigorous physical activity achieved and improvements in attention, processing speed, prefrontal cortex volume, and hippocampal volume. No significant relationships were found with memory, executive function, or basal ganglia volume changes.
The current findings contribute to the growing evidence that physical activity interventions targeting aerobic exercise can lead to enhanced cognitive performance in specific domains such as attention and processing speed for young adults. Results also suggest exercise may promote increased volume in prefrontal and hippocampal areas of the brain that support these cognitive abilities. Limitations include the short duration and sample characteristics restricting generalizability. Overall, this research supports the promising role that physical activity could play in optimizing cognitive and brain health during critical developmental periods of young adulthood. Future studies would benefit from exploring broader populations, various exercise prescriptions, and longer term outcomes.