The age you should start exercising regularly to ward off dementia has been revealed in new research - and it's not your 20s or 30s

Whether it's taking up running for the first time or going to the gym, we're often told that you have to start early in life to reap the benefits. It can feel like you've missed the boat if you only take up strength training or walking workouts in your 40s.

Exercising in your 20s and 30s does naturally offer benefits that can follow you throughout life, from improved muscle mass to cardiovascular health, but research suggests it's never too late to start exercising to take care of your brain.

Researchers from Boston University found that participants who were most active in 'midlife' (45 to 64) had a lower risk of developing dementia by as much as 41%. Those who were most active after 65 had a 45% lower risk of dementia, compared to those who were least active. There was no association between exercise in early adult life (26 to 44) and a lower risk of dementia.

The researchers looked at 1526 early adult–life, 1943 midlife, and 855 late-life participants who had taken part in the Framingham Heart Study, research spanning over 70 years.

Exercise intensity mattered, however. Those doing moderate and vigorous-intensity exercise in their 40s, 50s, and 60s saw the most benefits for brain health, while any intensity of exercise improved outcomes for those over 65.

Participants with the APOE4 gene, the strongest genetic risk factor for Alzheimer's disease, were also included in the study. The results showed that exercise did not protect these participants in midlife, but after 65, exercise reduced their risk by 66%.

If you've ever thought it's 'too late' to start, this is your sign to find an activity you enjoy and get going. The exercise that protects your brain is the one you do today, this month, and this year, not the one you should have started doing 10 years ago.

What is moderate and vigorous intensity exercise?

To take care of your brain in so-called 'midlife', the study found that moderate and vigorous (heavy) exercise was most effective. According to the NHS, which recommends 150 minutes of moderate-intensity exercise per week, this includes activities such as cycling, brisk walking, and gardening. Your heart rate will rise to the point where you can still maintain a conversation, but wouldn't be able to sing.

Vigorous or heavy-intensity exercise includes activities like hiking or running, where you'll noticeably be out of breath, and it'll feel like more of a struggle. The NHS recommends doing this for 75 minutes a week to reap the benefits.

Across both intensities, it's a good idea to spread this out over the week, with three or more sessions and rest days in between. While these are minutes of cardio activity, resistance training is also recommended - especially for women over 35 to improve bone density, muscle mass, and counter the effects of menopause.

A new study from the University of Sydney in PLOS Medicine has further highlighted these benefits, after the research found that women who meet these physical activity guidelines have around half the risk of dying from any cause compared to those who are inactive.

Tips for improving brain health

• Disconnect from stress: Chronic stress (burnout) is one of the "most damaging yet underestimated threats" for brain health, Dr Inmaculada Rodríguez Ulecia previously told woman&home. "Over time, it can impair memory and affect emotional regulation."
• Focus on your diet: "Eating a wide variety of colourful plant foods is one of the best ways to feed your brain,"  Dr Caitlin Hall, a neuroscientist and registered dietitian, told us. Prebiotic fibres and omega-30-rich foods are also worth including in plenty.
• Drink lots of water: "Even a little dehydration can affect memory, mood, and energy levels," says Dr Hall. Most health bodies recommend at least two litres every day.
• Give yourself a break: “Laughter, dancing, creativity. These are not luxuries. They are vital for a healthy, resilient brain," says the doctor.