It is well known that exercise can boost cognitive function. Previous studies, such as a 2021 study by Harvard University researchers, showed that moderate-intensity exercise can help improve memory and thinking skills by reducing insulin resistance and inflammation as well as improving sleep and mood. Now, a new study shows that these cognitive benefits would reduce if people are not getting enough sleep.
While regular physical activity may help prevent cognitive decline as people age, this effect may reduce if people are not getting enough sleep, according to a new study by University College London (UCL) researchers. The study, published in The Lancet Healthy Longevity, analysed data from more than 8,95O people aged 50 and over in England across ten years. The researchers examined how sleep and physical activity habits affected cognitive function over time, according to the press statement by UCL.
In this study, an episodic memory test (asking participants to recall a 10-word list) and a verbal fluency test were used to assess cognitive function. The findings showed that people who were more physically active but slept less than six hours showed faster cognitive decline overall, and their cognitive function was equivalent to those who engaged in less physical activity.
“Our study suggests that getting sufficient sleep may be required for us to get the full cognitive benefits of physical activity. It shows how important it is to consider sleep and physical activity together when thinking about cognitive health,” lead author Dr Mikaela Bloomberg said in the statement.
Consistent with previous studies, the latest findings showed that six to eight hours of sleep, along with higher levels of physical activity, contributed to better cognitive function. The researchers said that organisations such as the World Health Organisation have stated that physical activity can help maintain cognitive function, but it is important for interventions to consider sleep habits for long-term benefits.
Previous studies have found an association between sleep and cognitive function. For instance, a 2019 study published in the journal Sleep found a linear relationship between sleep and cognitive functioning; more sleep led to better cognitive performance, and vice versa.