Exercise May Enhance Cognitive Function for Up to 24 Hours, Research Indicates

Recent research from University College London indicates that the cognitive enhancements following physical exercise may persist for up to 24 hours. This study, published in the International Journal of Behavioral Nutrition and Physical Activity, examined the effects of physical activity on memory performance in older adults.

While previous studies have documented improvements in cognitive performance shortly after exercise, the duration of these benefits had remained unclear. The current investigation focused on individuals aged 50 to 83, revealing that those who engaged in moderate to vigorous activities experienced better memory recall the following day.

The research highlighted that reduced sedentary time and a minimum of six hours of sleep were correlated with enhanced memory test results. Additionally, deeper stages of sleep, particularly slow-wave sleep, were found to play a role in improving cognitive function. The study involved 76 participants who wore activity trackers over eight days while undergoing daily cognitive assessments.

Lead researcher from UCL emphasized that the findings suggest the memory benefits from physical activity extend beyond the immediate post-exercise period, potentially influencing cognitive performance into the next day. Moreover, the study indicates that quality sleep, especially deep sleep, further enhances these cognitive benefits.

The research defined moderate to vigorous physical activity as any activity that elevates heart rate, including brisk walking or climbing stairs. However, the authors noted the study's limitations, including its small sample size, which necessitates further investigation with a larger group of participants to validate the results.

Exercise is known to increase cerebral blood flow and stimulate the release of neurotransmitters linked to cognitive functions, effects that typically last for a few hours. However, the researchers pointed out that certain brain functions associated with exercise may have longer-lasting impacts. Previous studies have suggested that exercise can positively affect mood for up to 24 hours, and an earlier 2016 study found increased hippocampal activity for up to 48 hours following high-intensity interval training.

Maintaining cognitive health is crucial for older adults, impacting their quality of life and independence. The findings from this study underscore the importance of identifying daily factors that influence cognitive performance. While the immediate benefits of exercise on cognition appear to last longer than previously understood, the relationship between these short-term effects and long-term cognitive health remains an area of ongoing research.

To assess the relationship between different activity levels and cognitive performance, the research team analyzed data from wrist-worn activity trackers. They measured participants' sedentary behavior, light physical activity, and moderate to vigorous activity while also monitoring sleep duration and quality, distinguishing between lighter REM sleep and deeper slow-wave sleep.

The results indicated that an increase in moderate to vigorous physical activity relative to an individual's average was associated with improved working memory and episodic memory the following day. Furthermore, overall sleep duration correlated with better episodic memory and psychomotor speed. In contrast, increased sedentary behavior was linked to poorer memory performance the next day.

This study represents one of the first attempts to explore next-day cognitive performance using a 'micro-longitudinal' approach, tracking participants in their everyday environments rather than controlled laboratory settings. However, the participant pool was comprised of cognitively healthy individuals, which may limit the applicability of the findings to those with neurocognitive disorders.

The collaborative research involved experts from the UCL Institute of Epidemiology & Health Care, UCL Division of Surgery & Interventional Science, and the University of Oxford.