You can stroll your way to a younger, healthier brain

He adds: “People who are inactive have a higher risk of high blood pressure, of high blood glucose, high fat content in the body especially around the waist, and high cholesterol – or what’s called metabolic syndrome, a collection of recordable measurements which tells us we’re at risk of chronic long-term illness. Exercise reduces the risk of those features appearing.” And by keeping your blood pressure low, blood sugar low and the fat round your waist down, not only will you reduce your risk of chronic long-term illness, you will also increase your brain health, he says.

Conversely, he notes that our mortality rate increases by 2 per cent for every hour of sitting, and by 8 per cent where we’re on our backside for more than eight hours per day. Plus, studies have shown that sedentary behaviour is a predictor of Alzheimer’s. Goodwin advises “waging war on the chair”, taking a 10-minute movement break at least every 50 minutes, and making it a rule never to sit when you can stand.

But not only can we slow ageing by moderate exercise, we can turn back the years. “If you do enough moderate to intense exercise, you can reverse the ageing of the brain,” says Goodwin. He points to research by scientists at the University of Pittsburgh. Professor Kirk Erickson and his team recruited 120 sedentary older people (without dementia) and divided them into two groups. One walked around a track for 40 minutes a day, three days a week, the other did stretching exercises.

At the end of the one-year study, says Goodwin, the moderate exercisers experienced improvements in memory and brain health. “Parts of their brain, notably the hippocampus increased in volume by 2 per cent.” (The stretchers, meanwhile, sadly experienced a decrease in hippocampus volume by about 1.4 per cent.)

Boosting neurogenesis also has a positive impact on our cognitive reserve. “If you have a mentally demanding occupation, if you are well-read, if you continue your education and you tax the brain continuously throughout life, the brain develops all these networks of connections between the synapses, which temper the effects of Alzheimer’s,” says Goodwin. “The growth of new brain cells enables better resilience and better cognitive reserve. They work hand in hand.”

Exercise can have immediate benefits to your brain power – your memory and decision-making – whatever your age. Epidemiological evidence shows leading a physically active lifestyle reduces our risk of cognitive decline, from middle age onwards. If you’re fit in midlife, you’re likely to perform as well as – if not better – than younger inactive colleagues in memory and cognitive power. “Those who exercise aerobically and have an active lifestyle have vastly improved memories compared to those who don’t.” (Don’t expect instant results, but “your memory will slowly improve the fitter you get. And if you maintain your fitness it will keep on improving”.)

“Age is only a number,” adds Goodwin. “Actually how old you are depends on how well you’ve looked after yourself, what genes you got from your parents, and what your environment is like.” And only 25 per cent of how we and our brains age is down to DNA. “Seventy-five per cent is due to lifestyle and environment – and we can make those choices.”

So some people at 50 perform as if they were 30, whereas others are old before their time – and one indication of this, he says, is how fast they walk and how many steps they take. “The slower you walk and the shorter your step, the older you are.”

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Knowing this, can we correct it? “Yes,” says Goodwin. “We naturally slow down as we age. We should make the effort to keep our activity brisk. Push yourself when you’re walking.”

Crucially, incorporating the likes of regular brisk walks into our day helps to reduce inflammation. Goodwin says: “The other great thing about exercise and an active lifestyle is that it reduces inflammation massively. And inflammation is a proxy for ageing. The older you get, the more inflammation there is in the body. If you can reduce that inflammation, you’ll slow down ageing. If you slow down ageing, you’re at less risk of dementia.”

Along with a good social and sex life, diet, and quality sleep, “exercise is one of the big five that puts the boot on the throat of ageing. The relationship between adequate brain function and exercise is fundamental,” he says.

The Telegraph, London

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