Exercise Boosts Short-Term Memory in Older Adults for up to 24 Hours, Study Finds

Physical activity offers more than just immediate cognitive benefits, according to a new study from University College London (UCL). Researchers found that moderate to vigorous exercise not only improves brain function in the hours after activity but can enhance memory performance into the following day.

The study, published in the International Journal of Behavioral Nutrition and Physical Activity, analyzed data from 76 participants aged 50 to 83. Participants wore activity trackers for eight days and completed daily memory tests. The findings revealed that individuals who engaged in more moderate or vigorous physical activity than usual performed better on memory tasks the next day.

“Moderate or vigorous activity means anything that gets your heart rate up—such as brisk walking, dancing, or climbing stairs. It doesn’t have to be structured exercise,” explained lead author Mikaela Bloomberg, PhD, of UCL. “Our findings suggest the short-term memory benefits of physical activity may last longer than previously thought. Getting more sleep, particularly deep sleep, also seems to enhance memory improvement.”

The study also identified other factors influencing memory performance. More sleep—especially slow-wave sleep, a deep, restorative stage—was associated with better episodic memory (the recall of past events) and psychomotor speed (reaction times). Conversely, spending more time being sedentary than usual was linked to worse working memory the next day.

The team adjusted their analysis for various factors, including participants’ average activity and sleep patterns, ensuring that the results reflected short-term changes rather than long-term habits.

“Maintaining cognitive function is vital for older adults’ quality of life, independence, and well-being. This study provides evidence that exercise’s immediate cognitive benefits may extend longer than we previously thought,” said co-author Andrew Steptoe, PhD, professor of psychology and epidemiology at UCL. “However, it remains unclear if these short-term boosts contribute to long-term cognitive health.”

According to the study, exercise stimulates increased blood flow to the brain and the release of neurotransmitters like norepinephrine and dopamine, which support cognitive functions. While these neurochemical effects last for hours, other exercise-related changes—such as improved mood—may persist for up to 24 hours. Additionally, the authors explained that past research suggests high-intensity interval training (HIIT) can synchronize activity in the hippocampus (a brain region critical for memory) for up to 48 hours.

The researchers noted that their findings apply to cognitively healthy individuals and may not generalize to those with neurocognitive disorders. They also highlighted the need for larger studies to confirm their results and explore whether these short-term cognitive gains contribute to reducing dementia risk or slowing cognitive decline.