Evidence is growing that fitter people have bigger brains and better memories.
Keeping fit may even trigger the growth of new cells in the brain’s memory hub – helping protect against Alzheimer’s disease.
British experts say that what is good for the heart is also good for the head – and that even brisk walking is beneficial.
The latest evidence for that exercise boosts the brain as well as the body is in a special edition of the journal NeuroImage.
It includes a study from the University of Kentucky in the US, in which 30 men and women in their 50s and 60s were put through heart and lung tests while running on a treadmill.
They also underwent brain scans.
The results showed blood flow to the brain – and so the supply of oxygen and vital nutrients – to be higher in those who were fitter.
Another study, by US government scientists at the National Institutes of Health in Maryland, compared the brains of mice kept in cages with wheels with those housed without any exercise equipment.
Zeroing in on part of the hippocampus, the brain’s memory hub, and one of the first areas to be destroyed by Alzheimer’s, revealed that the mice with the wheels had up to three times as many new brain cells.
Study co-author Henriette van Praag told the Sunday Times: ‘For most people, physical health and brain health once seemed to have little connection.
‘This has been changed by discoveries in rodents that wheel-running increases producing of new neurons in the hippocampus.’
Other recent research has shown that even going for a brisk walk can help the brain grow.
The work, from the University of Pittsburgh in the US, found that going for a stroll three days a week boosted the size of the hippocampus and other key brain regions by up to 2 per cent.
While this might not sound like much, it is equivalent to taking two years off the brain’s age – an ‘enormous’ effect.
In contrast, the same brain regions shrunk away in people who swapped going for walks for a stretching routine.
In an introductory article to the latest research on exercise in NeuroImage, Oxford University Neuroscientist Heidi Johansen-Berg said: ‘Studying how physical and cognitive activity affects brain structure and function is particularly pressing given the growing global health burden of age-related cognitive and brain decline.’
Other experts also back exercise as a way to stay mentally fit.
Professor Linda Clare, an Exeter University expert in ageing and dementia, said walking, running and cycling ‘can all give the brain the boost it needs to stay healthy for longer.’
Professor James Goodwin, chief scientist at Age UK, which as part of the Global Council on Brain Health is compiling advice on how to best keep the brain sharp,added: ‘Brain deterioration is seen as inevitable and unpreventable.
‘But that is wrong – your lifestyle is intimately linked to the health of your brain.’
Dr Clare Walton, of the Alzheimer’s Society, said: ‘We know that what is good for the heart is good for the head and people who are physically active throughout their life have a reduced risk of developing dementia.
‘Of all the lifestyle factors known to impact your risk of developing dementia, taking regular exercise seems to be one of the best things you can do.
‘You don’t need to hit the gym to keep fit, try anything that gets your heart rate up for 30 minutes or more, like taking a brisk walk, a game of tennis or a dance class.
‘If you’ve not been active for a while, speak to your GP to find out which kinds of activities would be best to get you started again.’