Being active, especially in nature, is part of our genetic programming and ensures our cognitive performance up to a ripe old age.

Moving is an important part of a healthy lifestyle, contributing to general fitness, muscle control and coordination, and to a sense of wellbeing. Physical activity is also essential for maintaining adequate blood flow to the brain and may stimulate brain cell growth and survival.  It can improve mood, prevent mobility problems and increase social interaction [1]

For general physical health, research has shown that four types of movement should be included in your regular routine [2]:

  • Incidental physical activity: is the activity required to engage in common daily activities across our day. It is usually completed in short periods of time that build up over the course of the day. It is also known as “non-intentional physical activity”, to differentiate it from physical exercise – a group of physical activities that generally have higher intensity and are performed with the purpose of exercising, i.e., intentionally. Some examples of incidental physical activity are: walking, taking the stairs, cleaning the house and gardening.
  • Aerobic exercise or cardio exercise: is any physical exercise of low to high intensity that depends primarily on the aerobic energy-generating process. “Aerobic” is defined as “requiring free oxygen”, and refers to the use of oxygen to adequately meet the energy demands of the cells during exercise (oxygen-based metabolism). It provides cardiovascular conditioning and is performed at over a relatively long period of time. Examples of aerobics exercises are: jumping rope, running, swimming, playing ball games, rowing and brisk walking.
  • Strength or Resistance training: involves the performance of physical exercises which are designed to improve strength and endurance. It can be associated with the use of weights, bands or using your own body weight against gravity. Resistance training is intended to increase muscular mass which can improve metabolism in addition to maintaining muscle functionality, which contributes to healthy longevity.
  • Stretching or flexibility training: is a form of physical exercise in which muscles or tendons are deliberately flexed or stretched in order to improve muscle elasticity and muscle tone. The result is a feeling of greater muscle control, flexibility and range of movement.

How can physical activity help to prevent dementia?

Some effects of physical activity in dementia prevention are listed below [3]:

  • Reduces oxidative stress and free radicals’ formation
  • Reduces inflammation 
  • Increases Amyloid ß clearance
  • Improves glucose metabolism
  • Enhances BDNF levels
  • Helps to control stress
  • Reduces risk factors for dementia: obesity, type 2 diabetes, hypertension

Many studies have found that physical activity at any stage of life (childhood, youth, middle age or later life) is associated with greater intellectual function, lower risk for cognitive decline and for dementia.

It has been shown that physical activity can improve attention, processing speed, executive function, memory and working memory in adults above 55 years without dementia. It can even improve cortical thickness and brain volumes, especially in frontal lobes and hippocampus [4].

In addition, the results of a fairly recent study confirmed that the beneficial effects of aerobic exercise on executive function and brain volume begin at around 20 years of age [5], thus showing that this form of physical activity has a fairly positive impact on brain health at a fairly young age.

Physical activity has many health benefits and has been shown to improve brain function and prevent cognitive decline. Aerobic exercise (= exercise with oxygen-based energy metabolism) can improve brain volume and cognition. It is a relatively simple but very important and, most importantly, inexpensive factor that can be incorporated into most people’s lives and has been shown to mitigate the onset or progression of Alzheimer’s disease. And you can’t start early enough!

How much physical activity is recommended?

World Health Organization’s Recommendations for adults above 65 years old [1]:

  • Regular aerobic exercise (ex. brisk walking, running, swimming, bicycling…) should be initiated early in life as part of the daily routine. Combining exercise and leisure is the most efficient way to maintain constant physical activity throughout life. 
  • Adults aged 65 years and above should do at least 150 minutes of moderate-intensity aerobic physical activity throughout the week, or do at least 75 minutes of vigorous-intensity aerobic physical activity throughout the week, or an equivalent combination of moderate- and vigorous-intensity activity (see table 1).
  • Adults of this age group with poor mobility should perform physical activity to enhance balance and prevent falls on 3 or more days per week.
  • Muscle-strengthening activities (ex. hatha yoga, bodybuilding, gymnastic…) should be done involving major muscle groups, on 2 or more days per week.
  • When adults of this age group cannot do the recommended amounts of physical activity due to health conditions, they should be as physically active as their abilities and conditions allow.
  • Physical exercise should be continued for as long as possible for people with dementia, as it has been found to have a number of benefits. It can help prevent muscle weakness, mobility problems and other health complications associated with inactivity. It can help promote a normal day-night routine, improve mood and increase social participation.
Light exerciseModerate exercise Vigorous exercise
Slow walkingFast walking (>4 km/h)Climbing stairs/hiking
Slow bicyclingBicycling (15 to 20 km/h)Bicycling fast (>20 km/h)
Standing, doing light workGardeningPlaying soccer
Doing office workSlow joggingJogging (> 9 km/h)
Table 1: Exercise levels and corresponding activities

References:

  1. ↑ WHO guidelines – Risk Reduction of Cognitive Decline and Dementia, 2019
  2. ↑ Garber CE, Blissmer B, Deschenes MR, Franklin BA, Lamonte MJ, Lee IM, Nieman DC, Swain DP; American College of Sports Medicine. American College of Sports Medicine position stand. Quantity and quality of exercise for developing and maintaining cardiorespiratory, musculoskeletal, and neuromotor fitness in apparently healthy adults: guidance for prescribing exercise. Med Sci Sports Exerc. 2011 Jul;43(7):1334-59.
  3. ↑ McGurran H, Glenn JM, Madero EN, Bott NT. Prevention and Treatment of Alzheimer’s Disease: Biological Mechanisms of Exercise. J Alzheimers Dis. 2019;69(2):311-338. 
  4. ↑ Raji CA, Merrill DA, Eyre H, Mallam S, Torosyan N, Erickson KI, Lopez OL, Becker JT, Carmichael OT, Gach HM, Thompson PM, Longstreth WT, Kuller LH. Longitudinal Relationships between Caloric Expenditure and Gray Matter in the Cardiovascular Health Study. J Alzheimers Dis. 2016;52(2):719-29.
  5. ↑ Stern Y, MacKay-Brandt A, Lee S, McKinley P, McIntyre K, Razlighi Q, Agarunov E, Bartels M, Sloan RP. Effect of aerobic exercise on cognition in younger adults: A randomized clinical trial. Neurology. 2019 Feb 26;92(9):e905-e916. doi: 10.1212/WNL.0000000000007003. Epub 2019 Jan 30. Erratum in: Neurology. 2019 Jul 23;93(4):185. PMID: 30700591; PMCID: PMC6404470.