Four exercises that could reduce your dementia risk

A new study says that exercising once or twice weekly can reduce dementia risk by 10%. Photo / 123rf

As little as an hour of exercise once or twice a week – or 4000 steps a day – is all it takes to vastly reduce your risk

It’s official: frequent exercise gives you protection from dementia. After following more than 10,000 participants in their 50s for 16 years, researchers at the University of the Andes in Colombia determined that those who exercised regularly were 10% less likely to have developed dementia by their 70s than those who had never exercised at all.

Scientists have suggested for years that there is a link between regular exercise and reduced dementia risk, but this latest study, published in September, was the first to track people over the course of decades to assess the impact that moving frequently can have.

Even better news is that the amount of exercise needed to reap these benefits is likely much lower than you think. “Anyone who exercised at least once or twice a week was found to have this reduction in risk,” says Dr Gary O’Donovan, the British researcher who led the study.

It was also found that “weekend warriors”, those who only exercise on Saturdays and Sundays, benefited as much as people who exercised every day of the week. There was even some suggestion that they might have slightly more protection from dementia, “but there isn’t enough evidence to call it either way”, O’Donovan says.

Another study recently carried out using UK Biobank data, which also followed people over years, was consistent with these recent findings in Colombia. “This is great news because if you can reproduce the results in two different countries, then that relationship is likely real,” O’Donovan says.

The key message, he adds, is that some level of exercise is so much better for your brain than none at all, so people “should find an activity they enjoy and can stick to”. Here’s what the science says about how much exercise you need to do each week to stave off dementia – from sprinting and hardcore strength training, to walking and even yoga.

Aerobic exercises like cycling and jogging increase blood flow to the brain, promoting healthy ageing. Photo / 123rf

How it works

Simply put, “exercise is good for your brain health because it improves your brain chemistry, volume and function, all of which are linked to your risk of dementia in later life”, O’Donovan explains.

Devi Sridhar, a professor of global public health at the University of Edinburgh and a Level 3 certified personal trainer, says: “When you exercise, your muscles release small proteins and other chemicals that travel to your brain and help maintain brain matter that tends to degrade with age.”

“This is something called brain-muscle crosstalk,” she explains, where the brain communicates with your muscles in a complicated way.

For this reason, even a short 30-second burst of activity, such as a brisk walk to the bus stop or a handful of sit-ups, is better for your brain than a totally sedentary lifestyle.

At the same time, exercise increases the flow of blood and oxygen to your brain, helping it to retain its volume as you age. Regular exercise is also linked to improved mood and sleep, as well as lower blood pressure, and it helps you maintain a healthy weight. Stress, depression, a chronic lack of sleep and being overweight have all been shown to increase your dementia risk.

To get the full brain-boosting benefits that exercise can afford, it’s best to fit bigger chunks of movement into your week – though they needn’t be very long, or performed every day.

1. Aerobic exercise: An hour or two a week

The recent study from the University of the Andes only considered the impacts of aerobic exercise, which involves your body using oxygen to produce energy. Running, swimming, skipping and cycling are all forms of aerobic exercise.

Around half of the participants in the study who had a “weekend warrior” exercise style “said that they were doing so for 30 to 60 minutes, while the other half exercised in chunks of an hour or more”, explains O’Donovan.

His team did not identify any difference between the dementia risk of people who responded in these ways, and they didn’t split up the “weekend warriors” into people who were exercising either once or twice a week.

On this basis then, an hour of jogging, swimming or riding your bike every week – split across at least two sessions – should be enough to lower your risk of developing dementia.

If you prefer to exercise in short bursts every day, however, 20 minutes a day is deemed a safer amount.

“Some guidelines state that people should aim for 20 minutes of exercise every day, but either 10 or 30 could also be sufficient, depending on how vigorous that exercise is,” Sridhar says – that could mean a 10-minute sprint, a brisk 30-minute walk, a fast 10 minutes of laps in the pool or a leisurely 30 minutes of breaststroke.

“You could try to fit that in daily, or that could become 140 minutes or just over two hours riding your bike or swimming at the weekend,” Sridhar adds.

“I’d encourage people to think about what they can fit into their week, rather than what they can fit into every single day. Most of us live busy lives, and consistently getting enough exercise is crucial.”

Social sports like football or tennis can also count towards the “moderate to vigorous” exercise that you need at least 30 minutes of each week to protect yourself from dementia, O’Donovan says. Team games could also help counter the social isolation that many people feel as they age, which has also been associated with an increased dementia risk.

Yoga may protect women’s brains from age-related grey matter loss. Photo / 123rf

2. Yoga, Pilates or tai chi: One class on a weekend

Yoga as a form of exercise could be especially protective for women. One 2022 study found that a 12-week course of yoga protected women’s brains from grey matter atrophy, a key part of what changes in the brain when someone has dementia.

Pilates and tai chi meanwhile have been shown to protect against dementia by lowering stress and anxiety and lifting mood, with tai chi also improving cognitive function and skills like time management and decision-making in older people at risk of dementia.

What’s more, all three practices promote flexibility, which can prevent or alleviate chronic pain – which has been strongly linked to dementia development.

“Many people in Britain suffer from chronic pain in their neck or lower back,” Sridhar says. “Activities like yoga can help to alleviate this by correcting imbalances in different muscle groups in the body, and lengthening muscles like your hip flexors, which – rather than spinal issues – are so often responsible for back pain.”

Do you need to go to a yoga or Pilates class every day of the week? Not at all. “I would think that one class a week is enough to feel the benefits of a practice like this, and not to mention more affordable,” says Sridhar.

Moderate exercise reduces dementia risk, with 10,000 daily steps cutting the risk by nearly half. Photo / 123rf

3. Walking: 4000 steps or 40 minutes a day

We’re well used to hearing that 10,000 steps a day is the minimum that we need for physical and mental health. One 2022 study found that people aged between 40 and 79 who count at least 9800 steps every day were almost half as likely to develop dementia than those who walk very little.

But a study from the London School of Economics, published last year, found that “just five to six thousand steps a day is enough to feel the majority of the benefit that comes with movement”, Sridhar says. “That’s often much more feasible for people who are busy.”

The same 2022 study also found that those who walked just under 4000 steps every day were still 25% less likely to develop dementia.

Walking 4000 steps takes just over 60 minutes at a slow pace of 3.2km/h, while it would take an hour and 40 minutes to walk 6000 steps at the same speed. Faster walkers who stride at a pace of 8km/h could complete 4000 steps in 40 minutes, or 6000 steps in an hour.

With the average person in Britain walking between 3000 and 4000 steps every day, you might only need to add an extra 10 or 20 minutes of walking to your day, or an hour or two to your week, to boost your protection from dementia. A brisk walk counts as a form of aerobic exercise, too.

Strength training for just 45 minutes twice a week helps protect the brain. Photo / 123rf

4. Lifting weights: 45 minutes twice a week

Most research into the effects of exercise on dementia risk, and particularly the benefits of “weekend warrior” workout styles, has focused on aerobic exercise.

While less is known about the effects of strength training on dementia risk, some early research has suggested that heading to the weight rack at the gym could be particularly protective for older people at risk of the disease.

One 2020 study, from the University of Sydney in Australia, found that six months of lifting weights could slow or even halt degeneration in the areas of the brain associated with Alzheimer’s disease.

The participants in the study, who were aged over 55 and had been diagnosed with mild cognitive impairment, completed a total of just 90 minutes of strength training each week over two to three sessions. If lifting weights is your preferred form of exercise, half an hour three times a week or twice a week for 45 minutes could be enough to protect yourself from dementia.

Sridhar suggests that people who’d like to pick up strength training should think about the time needed each week in the same way as that needed for aerobic exercise – 10 minutes a day or an hour a week could be enough if you’re really pushing yourself, while 30 a day is safer if you prefer to take things easy.

“You also typically need days in between your sessions to recover if you’re strength training,” says Prof Sridhar. “This can be perfect for some people, who don’t have time to exercise every day, and it isn’t a large time investment.”

Alternatively, you could do lower body exercises on a Saturday and upper body exercises on a Sunday. “That doesn’t even have to be in a gym,” she adds. “Doing squats or pushups at home or in a park is still a form of resistance training.”

How Not to Die (Too Soon): The Lies We’ve Been Sold and the Policies That Could Save Us, by Prof Devi Sridhar, will be out in 2025