12/4:  Physical Activity & the Brain

Quick links:

Brain HQ:  https://v4.brainhq.com/

Handout

Canvas discussion board: https://sdccd.instructure.com/  

Quiz

Recording

Interested in hearing the lecture?  Click here to hear the lesson from Bridget Wright.  

Ideas for exercise

Don't forget to check out the HealthOA offerings by our excellent Emeritus instructors.

Also, our class discussed chair yoga.  Mari looked up some resources and found these few chair yoga resources; www.seachangeyoga.org/aarp-chair-yoga

Yoga for Arthritis video on YouTube from Johns Hopkins

10 minute chair yoga on YouTube

AARP Chair Yoga Video on YouTube

Finally, check with your local libraries for FREE chair yoga classes

 Have fun everyone and remember to check in with your medical provider BEFORE beginning any exercise program-Cheers to great health & wellness goals!


WHY does Physical Activity & Brain Health Matter?

As we have been learning in our brain fitness classes, living a healthy and active lifestyle may help you maintain brain health. In this lesson, we will look at the impact of physical activity and will learn why it may lead to brain health.  We will discover the short- and long-term effects of physical exercise which can result in positively impacting not only our brain health but also reducing the risk of other chronic conditions as well.

What is Physical Activity?

people being physically active

Physical activity encompasses any body movement that elevates energy levels beyond the resting state, thereby enhancing physical health and wellness. This includes a variety of activities such as brisk walking, gardening, yoga, golfing, swimming, and biking, each contributing uniquely to our overall health. 

Benefits and importance of physical activity

(HHSA 2018)

Benefits of Physical Activity

Engaging in physical activity offers numerous benefits. It enhances the health of the heart, muscles, and bones, and significantly improves brain health. This improvement manifests in enhanced memory, increased problem-solving skills, and better cognitive health, including aspects like speech, memory, attention, and visual processing. Furthermore, regular physical activity is known to reduce the risks of depression, anxiety, and cognitive decline, making it a cornerstone of a healthy lifestyle.

Importance of Physical Activity

Physical activity plays a pivotal role in the prevention of age-related cognitive decline. Studies have linked it to better overall health and aging, with a positive influence on brain health and mood. Notably, physical activity has been associated with a reduction in dementia and cognitive decline, while also enhancing brain structure and function. It's a key component in fostering healthy lifestyles, especially as we age.

Dementia and physical activity

Dementia, a common cognitive impairment, leads to a decline in cognitive abilities that affects one's ability to perform daily activities. It encompasses symptoms like memory loss, changes in thought patterns, and behavioral shifts. Regular physical exercise has been shown to significantly reduce the risk of dementia, highlighting the importance of staying active. 

Of all the lifestyle changes that have been studied, taking regular physical exercise appears to be one of the best things that you can do to reduce your risk of getting dementia. 

https://www.alzheimers.org.uk/about-dementia/risk-factors-and-prevention/physical-exercise 

cartoon brain on a treadmill exercising

One study looked at 454 older adults involved in a longitudinal study involving yearly physical exams and cognitive tests for 20 years, as well as donating their brains for research when they died.  They were given accelerometers which tracked their movement and physical activity around the clock.

Those who moved more scored better on the memory and thinking tests, and every increase in physical activity by one standard deviation was associated with a 31% lower risk of dementia. 

https://n.neurology.org/content/92/8/362 

Short term aerobic exercise

Short-term aerobic exercise is defined as exercise that lasts for at least 10-60 minutes at a time and is carried out under the condition of adequate oxygen supply, as described by Themanson & Hillman in 2006. This form of exercise can also improve thinking performance tests in older adults.

 According to findings from 29 clinical trials, engaging in regular exercise for a month or more can lead to improvements in memory, attention, and processing speed compared to regular nonaerobic exercise. 

https://pubmed.ncbi.nlm.nih.gov/16713115/


Exercise and aging

Does exercise late in life benefit the brain?  A literature review found 27 studies looking at the effect of physical activity on brain function in people 60 years of age. In 26 studies, there was a clear link between physical activity levels and cognitive performance, suggesting that exercise might be an effective way to reduce cognitive decline later in life.

https://www.alzheimers.org.uk/about-dementia/risk-factors-and-prevention/physical-exercise 

Exercise and Hippocampus volume

What's the most transformative thing that you can do for your brain today? Exercise! says neuroscientist Wendy Suzuki. Get inspired as Suzuki discusses the science of how working out boosts your mood and memory -- and protects your brain against neurodegenerative diseases like Alzheimer's. 

The hippocampus is one of the major brain areas of neuroplasticity and has been identified in research as a brain region which is sensitive to physical activity, and aerobic activity in particular.  Animal studies have shown that voluntary exercise is associated with hippocampal neurogenesis and prevents age-related decline in volume of the hippocampus.  Possible mechanisms suggested from these studies suggest trophic factors (such as insulin-like growth factor and brain-derived neurotrophic factor, AKA BDNF).  Angiogenesis (sprouting of capillaries from existing blood vessels) may also be a factor, which is associated with increased oxygen uptake.  

https://www.sciencedirect.com/science/article/pii/S1053811917309138  

A modest sized controlled trial showed one year of aerobic exercise resulted in a small increase in the size of the hippocampus (the brain area involved with memory), which was the equivalent of reversing one to two years of age-related shrinkage.  A study of 638 people in Scottland that asked people about their activity levels found those who were physically active at age 70 experienced less brain shrinkage over three years than those who were not physically active.  

https://www.alzheimers.org.uk/about-dementia/risk-factors-and-prevention/physical-exercise


A 2018 review and analysis of literature to determine the effects of exercise on hippocampal volume was conducted.  (Firth, 2018).  Although aerobic exercise did not significantly increase total hippocampal volume, there was a statistically significant positive effect of exercise in the left hippocampal volume in healthy older adults.  In addition, there was a significant effect of exercise on right hippocampal volume as well.  Researchers concluded that the positive effects from exercise are from the slowing down or preventing of volume loss over time.

In comparing other populations (psychotic, mild cognitive impairment, Alzheimer’s disease), no significant effect was seen in total or left/right hippocampal volumes. 

Study authors noted that the increase in hippocampus volume among older adults may be related to non-specific behaviors (such as an active lifestyle).  And, although mechanisms in the brain are still not understood, exercise has shown improvement in cardiorespiratory fitness, which is positively associated with improvements in cognitive performance.  So, aerobic exercise with an emphasis on cardiorespiratory fitness can be recommended for promoting healthy aging.

https://www.sciencedirect.com/science/article/pii/S1053811917309138  


Exercise in other areas  of the brain

Benefits of exercise to the brain and body

Research in recent years have looked at some of the benefits of exercise to the body and the brain.  In doing so, they have been able to pinpoint the changes that occur in the brain, and the reasons for these changes.  According to research, physical activity may benefit your brain in many ways including:

·         Promoting cardiovascular health

·         Improving blood flow to the brain

·         Reducing inflammation

·         Lowering levels of stress hormones

Exercise can also provide physical changes, such as increasing the thickness of the cerebral cortex and improving white matter (the nerve fibers which connect neurons).  It also promotes neuroplasticity, especially in the hippocampus. 

Aside from physical changes, exercise also benefits other areas of wellness such as happiness, hope, connection and courage.  Physically active people are happier and more satisfied with their lives.  They have a stronger sense of purpose and experience more gratitude, love and hope.  They are more connected to their communities and less likely to suffer from loneliness or become depressed.  And these benefits are seen throughout the lifespan, and among those living with serious mental and physical health challenges.  It is true whether their activity is aerobic, strength training, stretching or mind-body. 

https://health.clevelandclinic.org/why-exercise-protects-your-brains-health-and-what-kind-is-best/
https://greatergood.berkeley.edu/article/item/five_surprising_ways_exercise_changes_your_brain 


Here is a 15 minute workout designed for older adults from the Natitional Institute on Aging of the NIH

Here is a 10 minute video demonstrating how to do seated exercises.

Here is a 16 minute video demonstrating standing exercises

mental benefits of physical activity

Other reasons why you want to remain active

There are many other reasons why being active is good for the brain, including:

·         The exercise-induced mood boost can be found in any sustained physical activity.  Research suggests this may be due to endocannabinoids, brain chemicals in the brain that contain receptors for areas of the brain connected to stress.  When endocannabinoid molecules link to the receptors, they reduce anxiety and induce a state of contentment.  They also increase dopamine, further associated with optimism. This increases the pleasure we feel from being around others, thereby strengthening relationships. 

·         Regular exercise can remodel the reward system in your brain, increasing the circulation of dopamine and the number of dopamine receptors.  In this way, it can both decrease depression and expand the capacity for joy. Also, jump-starting the reward system can decrease the loss of dopamine receptors associated with aging.  In fact, active older adults have reward systems that more closely resemble individuals much younger than they are.

·         Regular exercise can also calm anxiety and modify the default state of the nervous system so it is more balanced and less prone to fight, flight or fright.  In fact, lactate (a by-product of exercise associated with muscle soreness) may have positive effects on brain health.  After it is released by the muscles, it travels through the blood to the brain, where it alters neurochemistry to reduce anxiety and protect against depression. 

·         Moving with others (as in a group situation) is one of the most powerful ways to experience joy.  Psychologists believe that the synchrony involved in group movement triggers a release of endorphins, which not only make you feel better, they help you to bond.  Those who are sharing an endorphin rush feel closer to one another afterwards.  This effect is multiplied by intensity and by music. 

·         New movements produced in physical activity sends information from the sensory receptors in your muscles, tendons and joints to your brain.  This ability to perceive your body’s movements, known as proprioception, help us to move through space while also improving our self-concept.  When participating in any physical activity, the sense of self is shaped by the qualities of your movement.  If you move with grace, your body perceives the elongation of your limbs and fluidity of the steps and realizes that it is graceful.  With a powerful mood, your body senses the speed and says that I am powerful.  Our physical accomplishments can change how we think about ourselves, and what we are capable of. 


Physical activity and mood

cortisol

Recent studies have demonstrated the many benefits of aerobic exercise, particularly in enhancing cognitive functions. One aspect is the increased blood flow to the brain observed in older adults and those with mild cognitive impairment during aerobic activities. This improvement in cerebral circulation is linked to enhanced memory capabilities, and highlights the direct impact of physical exercise on cognitive health.

Central to understanding this phenomenon is cortisol, commonly referred to as the stress hormone. Cortisol plays a pivotal role in cognitive improvement, with cortisol levels linked with brain function. During physical activity, cortisol is released, offering a range of positive benefits. It regulates energy and metabolism, suppresses inflammation by boosting immunity, and crucially, decreases stress, thereby contributing to overall cognitive health.

The relationship between physical activity and mood is also noteworthy. Exercise triggers the release of various chemicals in the brain, such as dopamine, serotonin, oxytocin, and endorphins, all of which significantly enhance mood. This biochemical change is a key factor in mood improvements following exercise.

Endorphins, neurotransmitters released by the pituitary gland and hypothalamus, play a crucial role in mood regulation. These natural hormones are known for their pain-blocking and stress-reducing capabilities, significantly improving mood and overall well-being. The pituitary gland, which regulates growth, metabolism, and reproduction, and the hypothalamus, managing body temperature, hunger, thirst, mood, sex drive, blood pressure, and sleep, work in tandem to release endorphins in response to various pleasurable activities, including exercise.

Euphoria is a state of intense excitement and happiness, which research suggests may increase with sustained physical activity. This heightened state of well-being is closely tied to the body's physiological responses to exercise.  This is why regular exercisers look forward to their workouts.

https://www.health.harvard.edu/mind-and-mood/the-no-drug-approach-to-mild-depression 

More about cortisol in exercise and stress


Our lesson describes the positive role of cortisol as a result  of exercise.  But you may also be aware of the negative effects of cortisol in long term stress.  How can this be good for one and not the other?

Cortisol, often termed the "stress hormone," plays a complex role in the body, and its effects can be seen differently during exercise compared to periods of stress. The key difference lies in the context and duration of cortisol release.

Cortisol During Exercise:

Cortisol During Stress:

Ultimately, the difference lies in the duration and context of cortisol release. During exercise, cortisol is part of a healthy, adaptive response, helping the body to meet the demands of physical activity. In contrast, during prolonged stress, elevated cortisol levels can become harmful, leading to a variety of physical and mental health issues. This difference highlights the importance of managing stress effectively and engaging in regular physical activity to maintain a healthy balance of cortisol and other hormones in the body.

https://www.health.harvard.edu/staying-healthy/exercising-to-relax 

Aerobic exercise and the brain

What is aerobic exercise?

Aerobic exercise, also known as cardio, is a type of physical activity that relies on the aerobic energy-generating process. It involves the use of oxygen to adequately meet energy demands during exercise via aerobic metabolism. The key characteristics of aerobic exercise include:

Some examples of aerobic exercise include activities like walking, jogging, swimming, cycling, dancing, and rowing. These activities can be adjusted in intensity to suit different fitness levels and health goals.  The key factor is that this activity is sustained and moderate intensity.  

Health Benefits: 

Regular aerobic exercise offers numerous health benefits, including improved cardiovascular health, reduced risk of chronic diseases (such as heart disease, diabetes, and certain cancers), weight management, improved mental health, enhanced immune function, and increased longevity.

physical activity recommendations per CDC

Benefits of aerobic exercise to the brain


Aerobic exercise is great for your brain, contributing to overall cognitive health, mental well-being, and neurological function. Here are some of the key benefits:

https://www.aimspress.com/article/doi/10.3934/Neuroscience.2022009
https://www.frontiersin.org/articles/10.3389/fnhum.2022.833149/full
https://www.frontiersin.org/articles/10.3389/fnagi.2019.00216/full
https://www.researchprotocols.org/2021/11/e33589 

Effect of Tai Chi on mild cognitive impairment, dementia and Parkinson's disease

What is tai chi? Tai chi is a practice that involves a series of slow gentle movements and physical postures, a meditative state of mind, and controlled breathing. Tai chi originated as an ancient martial art in China. Over the years, it has become more focused on health promotion and rehabilitation.

Study summaries from: https://www.nccih.nih.gov/health/tai-chi-what-you-need-to-know

https://www.nccih.nih.gov/health/tai-chi-what-you-need-to-know

Follow along with this beginner’s guide to a Tai Chi routine. Host Helen Liang will guide you through a variety of movements in this easy-to-follow instructional video. 

How much exercise is enough?

According to the CDC, adults need at least 150 minutes of moderate physical activity weekly or 75 minutes of vigorous activity for optimal brain and body health. This activity does not need to be done all at one time.  Experts suggest that moderate-intensity activity could be broken into 30 minutes a day, 5 days a week.  All adults also need muscle-strengthening activities two or more days a week. And adults 65 and older need balance activities about three days a week.


In truth, any amount of exercise is better than none. But many researchers suggest that at least 20 minutes of daily physical activity could be the for answer to reducing cardiovascular problems in your 70s. According to one longitudinal study which followed almost 2,800 people ages 65 or older over  20 years, people who exercised between 20 and 40 minutes per day of either moderate-intensity activity (such as brisk walking) or vigorous-intensity activity (such as gardening, working out in a gym, biking, dancing, or swimming) had fewer heart attacks and cardiovascular problems and a lower risk of premature death, compared with people who were not physically active. Among men, at least 20 minutes of daily exercise was associated with a 52% lower risk of cardiovascular problems, compared with people who did not exercise at all. The greatest benefits were among men ages 70 to 75. This was an observational study which does not conclude that exercise prevents heart disease. However, many studies have shown that moderate- or vigorous- exercise helps protect your heart and brain; and helps prevent diabetes, cancer, and other chronic diseases.

https://www.eurekalert.org/news-releases/943080
https://www.cdc.gov/nccdphp/dnpao/features/physical-activity-brain-health/index.htm 


What are some ways to increase our actvity for better brain health?

Our brain fitness class is all about changing your life for a better body and mind.  Your daily activity levels can play a major role in this.   Here are some practical suggestions to help you become more active in your daily routine:

Find activities that you enjoy and can realistically incorporate into your daily life. Consistency is more important than intensity when starting to increase your daily activity.

how to achieve your goals
smart goals

Summary


Our lesson emphasized the importance of incorporating physical exercise as well as activity into our daily routine.  Key takeaways include:

Find a way to increase your activity in your daily life.  Your brain and your body will thank you!