Older people with strong legs are likely to get along better when it comes to ageing of the brain, a decade-long study of more than 300 twins suggests.
Exercise releases chemicals in the body that may boost elderly brains, say the scientists, in the journal Gerontology.
The King’s College London team says leg power is a useful marker of whether someone is getting enough exercise to help keep their mind in good shape, BBC reported on Thursday.
It is difficult to untangle leg strength from other lifestyle factors that may have an impact on brain health and the study did not look specifically at dementia, experts say.
Leg power was measured (at the start of the study) using a modified piece of gym equipment that measured both speed and power of leg extension, while brain power was measured using computerized tasks that tested memory and mental processing skills.
Lead researcher Dr Claire Steves said: ‘When it came to cognitive ageing, leg strength was the strongest factor that had an impact in our study.
‘Other factors such as heart health were also important, but the link with leg strength remained even after we accounted for these.
‘We think leg strength is a marker of the kind of physical activity that is good for your brain.’
Alzheimer’s Society director of research Dr Doug Brown said the findings added to the growing evidence that physical activity could help look after the brain as well as the body.
‘However, we still don’t fully understand how this relationship works and how we can maximize the benefit,’ he said.
‘And we have yet to see if the improvements in memory tests actually translate into a reduced risk of dementia.’
Alzheimer’s Research UK director of research Dr Simon Ridley said: ’We know that keeping active generally can help reduce dementia risk and it’s important to take into account strength training as well as aerobic exercise.’
