The number of people with dementia in the Netherlands is expected to grow strongly in the coming decades and possibly even double. Exercise has positive effects in dementia, according to research. How this works exactly and to what extent is still partly unknown. In this article we list some data related to exercise and dementia.
Preventing dementia
More exercise can help prevent dementia or at least delay the onset of symptoms. According to the Health Council, people who comply with the exercise guidelines[1] a lower risk of dementia than people who don’t. New studies – in which healthy people are followed for years – also indicate that the risk is lower for people who exercise more[2]. Research in which people are followed for a long time is important to be more certain of what is cause and effect. Dementia often starts years before it is diagnosed. Less exercise can also be a consequence rather than a cause of dementia.
It is only partly known why exercise seems to protect against dementia. What is certain is that exercise has a positive effect on known risk factors for dementia, such as diabetes, high blood pressure, obesity, vascular disorders and inflammation. But even if the disease process does not run through these known risk factors, the risk of dementia can be limited.
Exercise in people with dementia
People with dementia often exercise little – and significantly less than their peers. Researcher Yvonne Hartman measured the activity of people living at home with and without dementia for seven days. The difference was largest for more intensive exercise, with 0.8 hours per week in people with dementia, compared to 1.5 hours in people without dementia. For light to moderately intensive exercise, the difference was relatively smaller (2.7 versus 3.5 hours)[3]. Exercising more intensively provides the strongest health effects.
Once people have dementia, exercise has positive effects, according to a lot of research. The focus is mainly on the ability to think, but researchers are also looking at other effects. Realize that research among the target group is very difficult. Real effects of exercise may not be picked up in research.
Thinking ability (cognition)
Thinking or cognition has different aspects such as memory, the ability to plan and the ability to process information quickly. These skills are impaired in dementia. In many studies, participants with dementia who exercise for a while score better on cognition than those who do not exercise. But the exact results differ between the studies. It is therefore difficult to indicate how large the effect really is and on which aspect of cognition exercise has the most effect.
For example, researcher Esther Karssemeijer of Radboudumc found that exercise mainly has an effect on psychomotor speed. This is an important predictor for being able to carry out activities of daily living such as washing and dressing yourself and doing the household. In other words: it seems that people with dementia who exercise more maintain their independence for longer, because they can perform basic activities independently for longer. The effect of exercise on psychomotor speed is comparable in magnitude to that of the use of certain medication used in Alzheimer’s dementia: the so-called cholinesterase inhibitors.[4].
Fellow researcher Lianne Sanders of University Medical Center Groningen analyzed what is known so far about the type and amount of exercise needed to have an effect on cognition. She summarized results from other studies in a meta-analysis and looked at effects in people with dementia and those with milder cognitive impairments. The latter can be a preliminary stage of dementia, but does not have to be. The greatest effect of exercise occurs with exercise sessions of 30 minutes or less at a time, followed four times or more per week. Less gain is achieved with longer, less frequent sessions. Exactly how that works is still uncertain. It may be that people become less tired during shorter sessions and therefore want to move more often and that interrupting sitting still more often is beneficial[5].
Physical Effects
Elderly people with dementia who exercise more have fewer physical limitations, a lower risk of falling and fewer falls than those who exercise less. The latter is especially important for people with dementia: because dementia also affects coordination, they fall more easily than their peers. Exercise can reduce falls by up to 30%[6]. It is also expected that exercise contributes to better muscle strength retention, as is known for the elderly in general[1]. These are all effects that contribute to more physical self-reliance and better mobility.
Depressive complaints
In people with dementia, depressive behavior and sadness are common. About 40 to 50% of people with dementia sometimes display depressive behaviour. Major depressive disorder, that is, when depressive behavior is present almost all day, occurs in approximately 20% of people with dementia. More exercise can reduce the number of depressive symptoms by up to 28%[6]. Exercise also appears to reduce behavioral problems associated with dementia.
- Health Council (2017). Physical activity and risk of chronic diseases. Background document of: Exercise Guidelines 2017. The Hague: Health Council.
- Iso-Markku P, Kujala UM, Knittle K, Polet J, Vuoksimaa E, Waller K. Physical activity as a protective factor for dementia and Alzheimer’s disease: systematic review, meta-analysis and quality assessment of cohort and case-control studies. Br J Sports Med. 2022 Jun;56(12):701-709.
- Hartman YAW, Karssemeijer EGA, van Diepen LAM e.a. Dementia Patients Are More Sedentary and Less Physically Active than Age- and Sex-Matched Cognitively Healthy Older Adults. Dement Geriatr Cogn Disord. 2018;46(1-2):81-89.
- Karssemeijer EGA, Bossers WJR, Aaronson JA et al. Exergaming as a Physical Exercise Strategy Reduces Frailty in People With Dementia: A Randomized Controlled Trial. J Am Med Dir Assoc. 2019 Dec;20(12):1502-1508.e1.
- Sanders LMJ, Hortobágyi T, Karssemeijer EGA, Van der Zee EA, Scherder EJA, van Heuvelen MJG. Effects of low- and high-intensity physical exercise on physical and cognitive function in older persons with dementia: a randomized controlled trial. Alzheimers Res Ther. 2020 Mar 19;12(1):28.
- Demurtas J, Schoene D, Torbahn G et al. European Society of Geriatric Medicine Special Interest Group in Systematic Reviews and Meta-Analyses, Frailty, Sarcopenia, and Dementia. Physical Activity and Exercise in Mild Cognitive Impairment and Dementia: An Umbrella Review of Intervention and Observational Studies. J Am Med Dir Assoc. 2020 Oct;21(10):1415-1422.e6.