An older woman walking briskly along a path in a green park

Exercise and Brain Health: What Lowers Dementia Risk

8 min read

In a UK Biobank study of 78,430 adults, about 9,800 steps a day was linked to about half the risk of dementia over about 7 years. The 2024 Lancet Commission on dementia lists physical inactivity among 14 changeable risk factors.

This guide covers what the step-count research shows, what exercise trials found for thinking skills, and a simple weekly routine based on the evidence.

20%
Lower risk of dementia of any type in more active adults, in a review of 58 studies
Iso-Markku et al. 2022, British Journal of Sports Medicine
25%
Lower dementia risk at about 3,800 steps a day, in 78,430 UK adults
Del Pozo Cruz et al. 2022, JAMA Neurology
51%
Lower dementia risk at about 9,800 steps a day, the step count with the largest risk reduction
Del Pozo Cruz et al. 2022, JAMA Neurology
62%
Lower dementia risk when the fastest 30 minutes of the day averaged about 112 steps a minute, a separate measure of pace
Del Pozo Cruz et al. 2022, JAMA Neurology
Sources: Iso-Markku et al. 2022, British Journal of Sports Medicine. Del Pozo Cruz et al. 2022, JAMA Neurology. All observational, so these are associations, not proof of cause.

Inactivity is a named risk factor

The 2024 Lancet Commission on dementia, led by Gill Livingston, lists 14 changeable risk factors: less education, hearing loss, high blood pressure, smoking, obesity, depression, physical inactivity, diabetes, excessive alcohol, head injury, air pollution, social isolation, untreated vision loss and high LDL (low-density lipoprotein) cholesterol. The Commission states that tackling these risk factors reduces the risk of developing dementia, and its 2024 report added vision loss and LDL cholesterol to the list.

In our view, movement is one of the most practical of these to change, because it needs no test or prescription and it is part of standard advice for blood pressure, weight and blood sugar too.

What the step-count research shows

A 2022 study in JAMA Neurology, led by Borja del Pozo Cruz, followed 78,430 adults aged 40 to 79 in UK Biobank, a large long-term UK health study, who wore a wrist activity tracker. Over a median of 6.9 years, 866 developed dementia. More daily steps were linked to lower risk. About 3,800 steps a day was linked to a 25% lower risk, and about 9,800 steps a day, the step count with the largest risk reduction, to a 51% lower risk. About 1 in 90 people in the study developed dementia, so these percentages are relative risk, not the chance of getting dementia.

Walking pace mattered too, as a separate measure. When the fastest 30 minutes of a person's day, not necessarily in a row, averaged about 112 steps a minute, dementia risk was 62% lower. The authors concluded that steps done at higher intensity showed stronger associations.

The study also split steps by speed. For incidental steps, taken at under 40 steps a minute, the largest risk reduction was at about 3,700 a day (42% lower). For purposeful steps, taken at 40 steps a minute or more, it was at about 6,300 a day (57% lower).

Lower dementia risk by step count and pace Percent lower risk, two step counts and one pace measure, 78,430 UK adults 25% 51% 62% 3,800 steps a day 9,800 steps a day 112 steps a minute pace, a separate measure
Source: Del Pozo Cruz et al. 2022, JAMA Neurology, UK Biobank, 78,430 adults, median 6.9 years. A hazard ratio of 0.49 means 51% lower risk. The pace bar is a separate measure from step count, so it is not more steps. Observational associations, not proof of cause.

These are observational associations from one cohort, so they show a link rather than proof that more steps prevent dementia. The study followed people for about 7 years, and early, undiagnosed dementia slows people down, so part of the link might run the other way. The 58-study review below found the link held in longer studies too.

Other types of exercise help too

A 2018 meta-analysis in the British Journal of Sports Medicine, led by Joseph Northey, reviewed 39 randomised controlled trials of exercise in adults over 50, 36 of them in the meta-analysis. Exercise improved cognitive function, by a small to moderate amount on average, and the benefit held across the thinking skills tested and in people with and without cognitive problems. Aerobic exercise, resistance training, multicomponent training (a mix of exercise types) and tai chi all showed benefits. Sessions of 45 to 60 minutes at moderate intensity or more were linked to benefit, and the authors recommended both aerobic and resistance exercise on as many days of the week as feasible.

A 2022 meta-analysis in the same journal, led by Paula Iso-Markku, pooled 58 studies. Physical activity was linked to a 20% lower risk of dementia of any type, and the link held in studies that followed people for 20 years or more, which reduces the chance that early, undiagnosed dementia explains it. Activity was also linked to a 14% lower risk of Alzheimer's disease and a 21% lower risk of vascular dementia. The authors noted possible publication bias for all-cause dementia and Alzheimer's disease, meaning some studies with weaker results might be missing.

The NHS advises adults aged 19 to 64 to do at least 150 minutes of moderate activity or 75 minutes of vigorous activity a week, plus strengthening activities on at least 2 days a week. For adults aged 65 and over, it gives the same weekly amounts and advises activities that improve strength, balance and flexibility on at least 2 days a week.

A simple weekly plan for brain health

These suggestions are ours, informed by the studies above and NHS guidance.

1
Build a daily step habit
Work toward a daily count of around 7,000 to 10,000 steps. If you are near 3,000 now, add about 1,000 steps a week. In the study, about 3,800 steps a day was linked to a 25% lower risk, and the largest reduction, 51%, was at about 9,800.
2
Add some brisk minutes
In the UK Biobank data, a faster pace in your quickest 30 minutes, about 112 steps a minute, was linked to lower risk. Count your steps for 1 minute to check your pace.
3
Train strength twice a week
Cover the main muscle groups on at least 2 days, in line with NHS guidance. Bodyweight, bands or weights all count. The trials in adults over 50 found benefits from resistance training too. Across all exercise types, sessions of 45 to 60 minutes at moderate intensity or more were linked to benefit.
4
Check your blood pressure
High blood pressure is one of the 14 risk factors named by the Lancet Commission. A regular check helps you catch a problem early.

Common mistakes to avoid

  • Treating it as all or nothing. In the UK Biobank study, about 3,800 steps a day, well short of 10,000, was already linked to a 25% lower risk. In our view, a rise from 3,000 to 5,000 steps a day is worth making.
  • Skipping strength work. The trials in adults over 50 found benefits from resistance training as well as aerobic exercise.
  • Starting too fast after years of low activity. In our view, build the load over weeks. The NHS advises speaking to a GP (general practitioner) first if you have not exercised for some time, or if you have medical conditions or concerns.

Frequently asked questions

Does walking lower dementia risk?
In a UK Biobank study of 78,430 adults, more daily steps were linked to lower dementia risk, and about 9,800 steps a day was linked to a 51% lower risk. These are associations from a large cohort, not proof of cause.
How many steps a day should I aim for?
In the study, about 3,800 steps a day was linked to a 25% lower risk and about 9,800 steps to the largest reduction for step count. In our view, around 7,000 to 10,000 steps a day is a sensible goal for most adults.
Is strength training useful for the brain?
A 2018 review of 39 trials in adults over 50, 36 of them in the meta-analysis, found that aerobic exercise, resistance training, multicomponent training and tai chi all improved cognitive function.
Does exercise reverse dementia?
These studies looked at dementia risk and at thinking skills in adults over 50. They did not test whether exercise reverses dementia.
Is it too late to start?
The trials in adults over 50 found better thinking skills with exercise. They did not measure dementia itself.

The bottom line

The 2024 Lancet Commission lists physical inactivity among 14 changeable risk factors for dementia. In a large UK study, more daily steps and a brisker pace were linked to lower dementia risk, and in trials of adults over 50, both aerobic and strength exercise improved thinking skills. In our view, build a daily walk, add some brisk minutes, train strength twice a week and keep an eye on your blood pressure.

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DT Fitness London builds simple, evidence-based training plans for busy adults, starting with a routine you will keep.
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Sources

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