Can Physical Activity Delay Alzheimer’s Symptoms in Older Adults?

Summary: Yes, physical activity can delay Alzheimer’s symptoms in older adults. In older adults with low baseline physical activity and an increased vulnerability to cognitive decline associated with Alzheimer’s, increasing daily step count can delay the onset of cognitive and functional decline.

Key Points:

• 7.2 million people over age 65 in the U.S. live with Alzheimer’s-related dementia
• Cognitive decline related to Alzheimer’s can disrupt daily life and reduce functional capacity/ability
• Experts identify two types of risk factors for Alzheimer’s-related dementia: non-modifiable and modifiable
• A new study shows that a modifiable risk factor – physical activity – can significantly delay cognitive and functional decline associated with Alzheimer’s disease

What is Alzheimer’s Disease?

According to the Centers for Disease Control (CDC), Alzheimer’s disease is:

“A progressive brain disorder cause by damage to nerve cells in the brain, which begins with mild memory loss and can lead to severe deficits in speech, daily function, and ability to successfully interact with people and the environment. Damage to the brain caused by Alzheimer’s is permanent and irreversible.”

While Alzheimer’s-related dementia is not uncommon, it’s not a normal part of the aging process in humans.

We’ll talk about that in a moment.

First, let’s look at the prevalence of Alzheimer’s-related dementia among older adults in the U.S. We retrieved this information from the report “2025: Alzheimer’s Disease Facts and Figures” published the Alzheimer’s Association.

Prevalence of Alzheimer’s-Related Dementia, Older Adults, 2025

• 65+: 11% of people with Alzheimer’s (7.2 million)
• 65-74: 26.3% of people with Alzheimer’s (1.9 million)
  • 1% of all people in U.S. age 65-74
• 75-84: 39% of people with Alzheimer’s (2.8 million)
  • 2% of all people in U.S. age 75-84
• 85+: 34.8% (2.5 million)
  • 4% of all people in U.S. age 85+

In addition, data shows that around 200,000 people between ages 30 and 65 report early-onset Alzheimer’s/early onset dementia.

Now let’s return to our discussion about Alzheimer’s-related dementia and how it differs from cognitive changes associated with older age.

Is It Just Getting Older or is it Alzheimer’s Dementia?

One reason millions of people around he U.S. want to know if physical activity can delay Alzheimer’s symptoms in older adults is the level of disruption cause by the symptoms.

Below, we’ll share a list of symptoms typically associated with Alzheimer’s-related dementia, alongside similar phenomenon among older people without Alzheimer’s-related dementia. We adapted this list from the same source we retrieved the prevalence data: the publication “2025: Alzheimer’s Disease Facts and Figures” published the Alzheimer’s Association.

Here’s what the experts at the Alzheimer’s Association want us to know about the differences between Alzheimer’s-related cognitive decline and common cognitive issues associated with older age:

Symptoms of Cognitive Decline Compared to Typical Signs of Aging

• Disruptive memory loss, e.g. forgetting recently learned things, forgetting names of loved ones, asking same questions repetitively.
  • Compared to forgetting things/names/new information temporarily but then remembering them.
• Difficulty solving problems, e.g. new difficulties making plans, working with numbers, or following a recipe.
  • Compared to making, then correcting, minor mistakes: think getting stumped by something related to household finances, then figuring it out.
• Difficulty with familiar daily tasks, e.g. problems grocery shopping, forgetting rules to a card game.
  • Compared to sometimes needing help with newer activities like setting recordings on a DVR or working a new smartphone
• Confusion related to time and place, e.g. losing track of days, seasons, and/or how they got where they are at the moment.
  • Compared to temporarily thinking it’s Friday when it’s Wednesday, then remembering that is, in fact, Wednesday
• Declining ability to understand visual images and/or spatial relationships, e.g difficulty judging distances, creating problems while driving.
  • Compared to age-related vision loss, e.g. vision issues caused by cataracts
• Problems with words in speech and writing, e.g. stopping mid-sentence or mid-conversation with no idea how to continue, or what they just said.
  • Compared to sometimes losing the right word at the wrong moment, e.g. having a word on the tip of their tongue, then remembering it.
• Misplacing objects/inability to remember recent activity or retrace recent steps/actions, e.g. losing phone, keys, eyeglasses, with complete inability to find them
  • Compared to losing something, retracing steps, then finding it.
• Declining judgment/increasing poor judgment, e.g. driving when they should not, making questionable decisions with money.
  • Compared to making occasional errors in judgment, then realizing and correcting them.

Driving when they shouldn’t drive can be a serious danger for people with Alzheimer’s-related dementia, as can making life-altering/consequential money decisions when they shouldn’t be making those decisions.

• Withdrawal from work and/or social activities, e.g. when inability to engage in conversation decreases motivation to socialize
  • Compared to staying home from being tired/losing energy at end of day/loss of interest in trivial activities
• Mood changes, behavior changes, personality changes, e.g. becoming uncharacteristically angry, suspicious, confused, anxious, or afraid when circumstances don’t necessarily explain those emotions/states of mind.
  • Compared to slowly getting crotchety, stuck in ways, and/or more irritable/less patient with advancing age

Reading this list, it’s clear why finding a way to delay the onset of cognitive decline in people with Alzheimer’s, or people at high risk of Alzheimer’s-related cognitive decline, is a priority among mental health and medical researchers.

We’ll share the results of an important new study on the topic, below.

Does Physical Activity Delay Alzheimer’s Symptoms in Older Adults?

In the study “Physical Activity as a Modifiable Risk Factor in Preclinical Alzheimer’s Disease,” a group of researchers report the results of an experiment designed to gauge the impact of physical activity among people with Alzheimer’s with and without risk factors for dementia.

As we mention in the introduction to this article, risk factors for dementia in Alzheimer’s are non-modifiable or modifiable.

Risk Factors: Non-Modifiable and Modifiable

Non-Modifiable:

• Age
• Genes
• Family history

Modifiable:

• Brain injury
• Smoking
• Diet
• Physical Activity
• Education
• Cognitive engagement
• Social engagement
• Hypertension
• Cardiovascular health
• Sleep
• Sensory loss, i.e. sight/hearing
• Diabetes
• Air pollution

This study measured the impact of a modifiable risk factor – physical activity – on Alzheimer’s symptoms by collecting data from 296 participants in the Harvard Aging Brain Study. Participants in the study were cognitively unimpaired at baseline, with baseline scores on cognition measured by two standard metrics, the Preclinical Alzheimer’s Cognitive Composite-5 (PACC5) and the Clinical Dementia Rating Sum of Boxes (CDR-SOB), with levels of physical activity measured by waistband-mounted pedometers.

Researchers collected data on cognition and activity at baseline, i.e. at the start of the study, and at yearly follow-up assessments over the 14-year study period. Each participant engaged in an average of 9 follow-up assessments. In addition, researchers labeled patients with higher levels of two proteins associated with dementia symptoms – Aβ and tau – as at high risk of developing dementia at baseline.

Here’s what they found:

Impact of Physical Activity on Delay in Alzheimer’s Symptoms in Older Adults

• Among participants with elevated baseline Aβ, meaning at high risk of dementia:
  • Taking 3,000-5,000 steps per day, considered a low level of physical activity, was associated with decreased tau accumulation
  • Low level physical activity (3,000-5,000 steps per day) was associated with decreased cognitive decline
  • Low level physical activity (3,000-5,000 steps per day) was associated with decreased functional impairment

Taking 3,000-5,000 steps a day delayed onset of cognitive decline and function by 3 years

• Among participants with elevated baseline Aβ:
  • Taking 5,000-7,500 steps per day, considered a moderate level of physical activity, was associated with “further attenuations of tau accumulation”
  • Moderate level physical activity (5,000-7,500 steps per day) was associated with decreased cognitive decline
  • Moderate level physical activity (5,000-7,500 steps per day) was associated with decreased functional impairment

Taking 5,000-7,000 steps a day delayed onset of cognitive decline and function by 7 years

• Among participants with elevated baseline Aβ:
  • Taking over 7,500 steps per day, considered a high level of physical activity, was associated with similar reductions and delays in tau accumulation, cognitive decline, and functional impairment as taking 5,000-7,500 steps per day.

This result indicates the positive impact of physical activity on delay in Alzheimer’s symptoms in older adults reaches a plateau between 5,000 and 7,500 steps.

We’ll discuss these results further, below.

Physical Activity and Alzheimer’s Symptoms in Older Adults: Promising News

Interviewed in the Harvard Gazette, study author Dr. Jasmeer Chhatwal, physician and researcher at Mass General Brigham Hospital, Department of Neurology, characterizes these results as follows:

“This [outcome] sheds light on why some people who appear to be on an Alzheimer’s disease trajectory don’t decline as quickly as others. Lifestyle factors appear to impact the earliest stages of Alzheimer’s disease, suggesting that lifestyle changes may slow the emergence of cognitive symptoms if we act early.”

The results of this study are important because the brain damage, cognitive decline, and functional impairment associated with Alzheimer’s – as of now, to date – are permanent and irreversible. Therefore, delaying the onset of these symptoms critical. It can extend typical cognitive and daily function for as long as 7 years with a moderate level of activity, and for as long as 3 years with a low level of activity.

To reiterate, the low level of physical activity that can delay Alzheimer’s symptoms in older adults is 3,000 to 5,000 steps a day, and the moderate level moderate level of activity that can delay Alzheimer’s symptoms in older adults is 5,000 to 7,500 steps per day.

Both those step counts are achievable and appear to be well worth the effort. We’ll close with insight from another researcher and author on the study, Dr. Wai-Ying Wendy Yau, also interviewed for the Harvard Gazette:

“We want to empower people to protect their brain and cognitive health by keeping physically active. Every step counts – and even small increases in daily activities can build over time to create sustained changes in habit and health.”