What if you could meaningfully lower your risk of dementia with far less exercise than you ever thought necessary? Exciting new research says that you absolutely can — and the bar is much lower than most people realize.
How 35 Minutes of Exercise Reduces Dementia Risk
For many of us, the word ‘exercise’ conjures images of gyms, sweat, and long hours of effort. It can feel like something meant for younger, fitter people — or like something you’d need to do a lot of to make any difference at all. If that’s held you back, here is some genuinely wonderful news.
A major 2025 study from the Johns Hopkins Bloomberg School of Public Health analyzed data from nearly 90,000 adults and found that engaging in as little as 35 minutes of moderate to vigorous physical activity per week — compared to no activity at all — was associated with a 41% lower risk of developing dementia. Let that sink in. Thirty-five minutes. That’s five minutes a day, or one short walk every other day.
More Movement, More Protection Against Dementia
As weekly activity increased, so did the protection. Those who exercised between 70 and 140 minutes per week saw their dementia risk drop by around 63%. Those who reached 140 minutes or more — still just 20 minutes a day — saw a 69% reduction. These are striking numbers, but the most important takeaway is that you don’t need to reach the higher levels to benefit enormously. Even the smallest amount of movement makes a real, measurable difference.
Exercise Reduces Dementia Risk Even for Frail Adults
Perhaps most encouraging of all: the researchers found these benefits held true even for frail older adults — people typically considered at the highest risk and least physically able. Movement, at almost any level, appears to be protective for the brain. There is no threshold you must cross before it starts working for you.
What Counts as Brain-Healthy Exercise?
What counts as moderate activity? Anything that gets your heart beating a little faster and your breathing slightly deeper. A brisk walk around the neighborhood. Gentle cycling on a stationary bike. Swimming or water aerobics. Dancing in your living room. Gardening with some vigor. These are not strenuous activities — they are the pleasant, manageable movements of an engaged life.
How Exercise Protects Your Brain
Exercise benefits the brain through several pathways. It increases blood flow, delivering more oxygen and nutrients to brain cells. It stimulates the release of a protein called BDNF — sometimes called ‘fertilizer for the brain’ — that supports the growth and health of neurons. It reduces inflammation, lowers blood pressure, and improves sleep, all of which further protect cognitive function.
If you haven’t been active in a while, please speak with your doctor before starting anything new. Begin very gently — even a five-minute walk counts. Be patient and kind with yourself as you build. The goal isn’t perfection. It’s simply to move a little more than you did yesterday. Your brain will notice, and it will be grateful.
At Advanced Neuropsychology and Psychology Services, PLLC (ADVNPS), we commonly assess cognitive health and provide personalized recommendations — including lifestyle factors like physical activity — to help protect and maintain brain function. Learn more about neuropsychological services at ADVNPS, or visit our website at https://www.advnps.com.
To learn more about this topic, visit the groundbreaking 2025 study from Johns Hopkins here.