Mark Dreher PhD (January 2014)

Cognitive Benefits of Exercise for Adults

January 2014

“Lack of activity destroys the good condition of every human being, while movement and methodical physical exercise save it and preserve it.” - Plato

“… from nothing else but the brain come joys, delights, laughter and sports, grief, despondency, and lamentation.” - Hippocrates

“Walking is the best possible exercise. Habituate yourself to walk very fast.”

“A strong body makes a strong mind.”- Thomas Jefferson

“Physical fitness is not only one of the most important keys to a healthy body, it is the basis of dynamic and creative intellectual activity.”- John F Kennedy

“A vigorous five-mile walk will do more good for an unhappy but otherwise healthy adult than all the medicine and psychology in the world.”

Paul Dudley White“The Father of American Cardiology”

“The reason I exercise is for the quality of life I enjoy.”

Kenneth H. Cooper“the Father of Aerobics”

Brain Facts that Need to be Respected Every Day!Fact # 1: Although the human brain is only 2% of the body weight, it receives about: - 15% of the cardiac output- 20% of total body oxygen consumption - 25% of total body glucose utilization

The brain is the most metabolically active organ and therefore prone to oxidative and inflammatory stress damage, which may deteriorate cognitive function.

Fact # 2: The human brain is in a constant state of change such that: - Over the lifespan new neurons may be formed while

others will die and new synapses are created while others are eliminated.

- Brain cerebral systems are not purely hard-wired and can be significantly influenced by many non-genetic factors such as physical activity, cognitive activity, sleep and nutrition.

Global Trends in Fitness

Globally, physical activity is declining with the high prevalence of sedentary behaviors in industrialized society.

Sedentary lifestyles are accompanied by increasing rates of obesity, type-2 diabetes, neurodegenerative diseases and other metabolic disorders.

Promoting adherence to programs of regular physical activity is one of the greatest challenges in the field of health promotion.

Ng and Popkin Obes Rev. 2012; 13(8): 659–680; Centers for Disease Control and Prevention, 2012 & 2013

How Much Aerobic Activity is Generally Recommended?

http://www.cdc.gov/physicalactivity/everyone/guidelines/index.html

Adults (18 + years) *Aerobic activity recommendations for adults include moderate-intensity aerobic activity for 2 hours and 30 minutes (150 minutes)(i.e., brisk walking) every week or 1 hour and 15 minutes (75 minutes) of vigorous-intensity aerobic activity (i.e., jogging or running) every week.

*150 minutes each week sounds like a lot of time, but it's not. That's 2 hours and 30 minutes. You can even break it up into smaller chunks of time during the day as it's about what works best for you, as long as you're doing physical activity at a moderate or vigorous effort for at least 10 minutes at a time.

United States Physical Activity Report Card for Adults

Less than half of all adults get the recommended amount of physical activity.

Men (52%) are more likely than women (43%) to meet the physical activity guidelines for aerobic activity.

Younger adults are more likely to meet the physical activity guidelines for aerobic activity than older adults.

Americans living in the South are less likely to be physically active than Americans living in the West, Northeast and Midwest regions of the country.

http://www.cdc.gov/physicalactivity/data/facts.html

Physical activity helps people become and stay healthy.

People who are physically active tend to live longer and have lower risk for heart disease, stroke, type 2 diabetes, depression, and some cancers.

Physical activity can also help with weight control and brain learning and processing.

http://www.cdc.gov/physicalactivity/data/facts.html

Regular Physical Activity Health Benefits for Adults

Cognitive Function Benefits Associated with Exercise for Adults: Overview

Neurogenesis spurs the growth of new nerve cells in an important brain memory center called the hippocampus.

Kirk-Sanchez and McGough. Clinical Interventions in Aging. 2014;4(9):51-62; Portugal et al. Neuropsychobiology. 2013; 68:1-4; Mind, Mood & Memory, Combating Memory Loss. Massachusetts General Hospital. 2012

Angiogenesis creates new brain blood vessels to help maintain and expand volume in key regions, such as the hippocampus, that are associated with cognitive function.

Neuroplasticity develops new brain connections by promoting changes in neural pathways and synapses for healthy development, learning, memory, and recovery from brain damage.

Healthy Brain Signals increase levels of (1) brain-derived neurotrophic factor (BDNF), a chemical that improves brain synapses and (2) endorphins that promote a feeling of well-being.

Neuroprotection associated with increases in the body’s natural antioxidant defense system and other functions to defend brain health.

Helps to control mood and stress management (e.g., quality of life, reduce occupational burnout risk).

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Cerebral Blood Flow increases to deliver more oxygen and nutrients and remove waste products from brain regions responsible for learning and memory.

Potential Benefits of Exercise Brain Mechanisms Associated with Exercise

Helps to promotes memory, reasoning, planning & IQ (especially in women).

Helps to slow shrinkage of brain and increases hippocampus volume, important for learning, memory, processing speed.

Helps reduce the risk for neurodegenerative diseases.

Helps to improve cognitive function in adults with mild to moderate intellectual disabilities.

Recent Aerobic Fitness and Cognition Research Highlights: Young and Middle Aged Healthy Adults

Research with 20 year old males showed that a single bout of moderate aerobic exercise for about 30 minutes improved post exercise cognition, most prominently for memory, reasoning and planning by between 20-35% and decreased the time taken to perform the tests (Nanda et al. J Clin Diagnostic Res. 2013;7(9):1883-1885).

In young to middle age adults (18-45 years), research findings provided compelling data to suggest that greater levels of physical exercise are associated with larger volume of the brain hippocampus (Killgore et al. Scientific Reports. 2013; 3:3457).

In healthy young to middle age adults, research indicates that physical exercise is associated with higher intelligence (IQ) in women, whereas exercise was only slightly associated with higher IQ in men (Killgore and Schwab. Percept Mot Skills. 2012; 115(2):605-617).

Study findings suggest that simultaneous light to moderate-intensity physical activity during vocabulary learning facilitated memorization of new material in young adults (19-33 years] (Schmidt-Kassow et al. PLOS ONE.2013; 8(5):e64172; Schmidt-Kassow et al. Neuro-science Letters.2010; 482:40-44).

Aerobic fitness improved cognitive attention processing only in younger adults (18-22 years) when compared to older adults (61-73 years) (Pontifex et al. Psycho-physiology. 2009; 46(2):379-387).

Cerebrovascular blood flow velocity was significantly improved irrespective of age after 12 weeks of a cycling exercise program for all adult regardless of ages but the response was greater for younger adults (18-28 years of age) compared to older adults (58-68 years of age). (Murrell, et al. Age. 2013; 35(3):905-910).

Research findings suggest that regardless of age (young (19-29 years and older 59-65 years) adults’ cognitive (executive function) was improved with exercise and higher cerebrovascular blood flow was strongly associated with improved cognition (Lucas et al. Exp Gerontol. 2012; 47(8):541-551).

Students (averaging 20 years) with mild to moderate intellectual disabilities who participated in 8-weeks of moderate aerobic training performance showed significantly improved in processing speed by over 100%. (Pastula et al. J Strength Conditioning Research. 2012; 26(12):3441-3448).

Killgore et al. NeuroReport. 2013;24:962-967.

Physical Exercise Appears to Increase the Eating Preference for “Healthier Foods”

High calorie dense foods (e.g. cheese burgers, ice cream, cake, French fries, candy)

Background: Recent evidence suggests that regular physical exercise may also affect the responsiveness of regions of the brain to food stimuli.

Design: This study examined whether the total number of minutes of self-reported weekly physical

exercise was related to the responsiveness of appetite and food reward-related brain regions to visual presentations of indulgent foods and healthy food images during functional MRI.

While undergoing scanning, 37 healthy adults (15 women and 22 men; average age 30 years) viewed images of Indulgent and low-calorie foods and provided desirability ratings for each food image. The correlation between exercise minutes per week and brain responses to high calorie dense vs healthy foods was evaluated in brain regions previously implicated in responses to food images.

Results: Higher levels of exercise were significantly correlated with lower brain responsiveness to

higher calorie dense foods.

These findings suggest that physical exercise may be associated with reduced activation in food-response and a reduced preference for higher calorie dense foods , particularly those with a savory flavor.

Conclusion: Physical exercise may confer a secondary health benefit of healthy eating beyond its primary

effects on cardiovascular and cognitive fitness and energy expenditure.

More research is needed on the effects of exercise on healthy eating preference to confirm this study.

Healthy foods (e.g. fruit, vegetables salads, fish, or whole grain)

Case Study #1: Aerobic Exercise and Cognitive Performance in Adults 18 Years or Older

Background: One strategy that has gained increased attention is the use of aerobic exercise to improve

neurocognitive functioning. Although the value of exercise has been critically examined in review articles and meta-

analyses, there is still more to be learned about the magnitude of the effect of physical activity on enhanced neurocognitive function.

Methods: A systematic literature review was conducted of randomized clinical trails examining the

association between aerobic exercise training and neurocognitive performance conducted between January, 1966 and July, 2009.

Suitable studies were selected for inclusion according to the following criteria: mean age 18 years of age or older, duration of treatment greater than 1 month, incorporated aerobic exercise components, exercise training was supervised, the presence of a non-aerobic-exercise control group.

Results/Conclusions: 29 studies met inclusion criteria and were included in the analyses representing data from 2,049

participants. Aerobic exercise training demonstrated modest but significant improvements in attention and processing

speed, executive function, and memory but the effects of exercise on working memory were less consistent. Individuals with mild cognitive impairment tended to demonstrate greater improvements in memory relative

to non-cognitive impaired subjects and longer periods of exercise were associated with greater gains in attention and processing speed.

Smith et al. Physchom Med. 2010; 72(3):239-252.

Case Study #2: Moderate Aerobic Exercise Improves Cognitive Function in Young Adults with Intellectual Disabilities

Background:Intellectual disabilities (IDs) is the most prevalent of all developmental disabilities. In addition to cognitive impairment, young adults with intellectual disabilities are also

more likely to be in poor health. Exercise may help ameliorate both of these deficits.

Methods: 14 students (averaging about 20 years of age) with mild to moderate IDs participated in

an 8-week comprehensive exercise intervention program based on circuit training, aerobic dancing, and adapted sport activities. Sessions lasted 45 minutes, and intensity was maintained at 60–70% of maximum heart rate.

Cognitive improvement was measured before and after the exercise program

Results/Conclusions: Moderate-intensity exercise training resulted in meaningful improvements in the cognitive functioning and

aerobic fitness of young adults with IDs with significant improvements in cognitive processing speed of over 100%.

Aerobic fitness was significantly improved (mean improvement in aerobic fitness was 17.5%). These effects support the inclusion of exercise into the lives of young adults with ID to promote their physical

and cognitive health.

Pastula et al. J Strength Conditioning Research. 2012; 26(12):3441-3448.

Case Study #3: Aerobic Exercise & Brain Volume in Healthy Middle Aged Adults Background: Physical exercise appears to facilitate improved brain function, particularly within the hippocampus, the brain region most critical for memory formation and spatial representation. Better aerobic fitness has been reliably associated with increased hippocampal volume and improved cognitive functioning in children and elderly adults, but until this study almost no data were available concerning this relationship in healthy early to middle aged adults.

Methods: 61 healthy adult volunteers (33 males; 28 females) ranging in age from 18 to 45 years from the

Boston metropolitan area participated in the neuroimaging study. No attempt was made to select participants based on particular physical exercise habits or

physical fitness level. The body mass index (BMI) of the sample ranged from 19.2 to 35. Upon arrival at the laboratory, participants completed an information questionnaire about their

daily routines, which included questions about exercise, diet, height, weight, and sleep habits.Structural MRI and brain images were analyzed using voxel-based morphometry for each subject.

Results/Conclusions: These findings provide compelling data to suggest that greater levels of physical exercise are associated with

larger volume of the hippocampus during the years of early to middle adulthood. The relation between increasing physical activity and optimal adult cognition and brain function is rapidly

evolving.

Killgore et al. Scientific Reports. 2013; 3:3457

Case Study #4: Aerobic Exercise and Occupational Burnout

Background: Burnout is defined as a gradual depletion of energy combined with a loss of motivation and commitment after prolonged exposure to high occupational stress. Examples include high workload, role conflicts, lack of participation or social support, injustice, uncertainty, under-reward, ambiguity, job insecurity, job complexity, as well as structural constraints.

Methods: Subjects studied were 12 males (range 36–65 years) scoring high on

emotional exhaustion and depersonalization subscales. Moderate aerobic program of 2–3 trainings per week for 12 weeks.

Results/Conclusions: Increased exercise reduced overall perceived stress as well as symptoms of burnout and

depression. Profiles of mood states improved considerably after single exercise session. Among burned-out people, the findings provide preliminary evidence that exercise has

the potential to reduce stress and the development of a deeper depression.

Gerber et al. BMC Research Notes. 2013; 6:78

“To keep the body in good health is a duty… otherwise we shall not be able to keep our mind strong and clear.” - Buddha

“If we could give every individual the right amount of nourishment and exercise, not too little and not too much, we would have found the safest way to health.” - Hippocrates