Regular physical activity may protect against cognitive decline as we get older, but this protective effect may be diminished for people who are not getting enough sleep, according to a new study
The study, published in The Lancet Healthy Longevity, looked at cognitive function over 10 years in 8,958 people aged 50 and over in England. The research team investigated how different combinations of sleep and physical activity habits might affect people’s cognitive function over time.
They found that people who were more physically active but had short sleeps – less than six hours on average – had faster cognitive decline overall, meaning that after 10 years their cognitive function was equivalent to peers who did less physical activity.
Lead author Dr Mikaela Bloomberg (UCL Institute of Epidemiology & Health Care) said: “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.
“Previous studies examining how sleep and physical activity might combine to affect cognitive function have primarily been cross-sectional – only focusing on a snapshot in time – and we were surprised that regular physical activity may not always be sufficient to counter the long-term effects of lack of sleep on cognitive health.”
