The cognitive boost from exercise can last until the following day according to a study by the University College London (UCL), published in the International Journal of Behavioral Nutrition and Physical Activity.

While it was previously known that exercise can give a memory boost, this study is significant in that it proves the benefits extend for longer than had been previously recognised. 

The research team looked at data from 76 men and women who wore activity trackers for eight days and took cognitive tests each day. Researchers found that people aged 50 to 83 who did more moderate to vigorous physical activity than they usually would did better in memory tests the following day.

Lead author, Dr Mikaela Bloomberg, from UCL Institute of Epidemiology and Health Care, said: “Our findings suggest that the short-term memory benefits of physical activity may last longer than previously thought, possibly to the next day instead of just a few hours after exercise. Getting more sleep, particularly deep sleep, seems to add to this memory improvement.

“Moderate or vigorous activity means anything that gets your heart rate up – this could be brisk walking, dancing or walking up a few flights of stairs. It doesn’t have to be structured exercise.”

Exercise increases blood flow to the brain and stimulates the release of neurotransmitters, such as norepinephrine and dopamine, which help a range of cognitive functions. These neurochemical changes are understood to last up to a few hours after exercise. However, the researchers noted that other brain states linked to exercise lasted for up to 24 hours.

Co-author Professor Andrew Steptoe, said: “Among older adults, maintaining cognitive function is important for good quality of life, wellbeing, and independence. It’s therefore helpful to identify factors that can affect cognitive health on a day-to-day basis.

“This study provides evidence that the immediate cognitive benefits of exercise may last longer than we thought. It also suggests good sleep quality separately contributes to cognitive performance.

“However, we can’t establish from this study whether these short-term boosts to cognitive performance contribute to longer term cognitive health and though there is plenty of evidence to suggest physical activity might slow cognitive decline and reduce dementia risk, it’s still a matter of some debate.”

The team found that more moderate or vigorous physical activity compared to a person’s average was linked to better working memory and episodic memory (memory of events) the next day. 

More sleep overall was linked to improved episodic and working memory and psychomotor speed (a measure of how quickly a person detects and responds to the environment). More slow-wave sleep was linked to better episodic memory.

Conversely, more time spent being sedentary than usual was linked to worse working memory the next day.

Among the study limitations, the researchers noted that the participants were a cognitively healthy group, meaning the results might not be true for people who have neurocognitive disorders. As it was a small study, the research team says it needs to be replicated with a larger sample of participants before results can be certain.

The study, titled Association of accelerometer-measured physical activity, sedentary behaviour and sleep with next-day cognitive performance in older adults: a mciro-longitudinal study involved researchers from the UCL Institute of Epidemiology and Health Care, UCL Division of Surgery and Interventional Science and the University of Oxford, and received funding from the UK’s Economic and Social Research Council (ESRC).