Mark Dreher PhD (January 2014)

Cognitive Benefits of Exercise for Children and Teens

January 2014

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: - During 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.

How Much Aerobic Activity is Recommended?

Children (6-17 years old) *Aerobic activity should make up most of a child's 60 or more minutes of physical activity each day. This can include either moderate-intensity aerobic activity, such as brisk walking, or vigorous-intensity activity, like running. Be sure to include vigorous aerobic activity at least 3 days per week.

http://www.cdc.gov/physicalactivity/everyone/guidelines/index.html (March 2011)

*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: Children

In a nationally representative survey, 77% of children age 9-13 years reported participating in free-time physical activity during the previous 7 days.

In 2011, 29% of high school students surveyed had participated in at least 60 minutes per day of physical activity on all 7 days before the survey, and only 31% attended physical education class daily.

Participation in physical activity declines as young people age.

http://www.cdc.gov/healthyyouth/physicalactivity/facts.htm (February 19, 2013)

Helps build healthy bones and muscles.

Helps reduce the risk of developing obesity and chronic diseases, such as diabetes and cardiovascular disease.

Reduces feelings of depression and anxiety and promotes psychological well-being.

Can help improve students’ academic performance, including: (1) academic achievement and grades, (2)academic behavior, such as time on task, and (3) factors that influence academic achievement, such as concentration and attentiveness in the classroom.

http://www.cdc.gov/healthyyouth/physicalactivity/facts.htm (February 19, 2013)

Regular Physical Activity Health Benefits in Children

Proposed Benefits of Aerobic Fitness on Cognitive Function Based on Current Research

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 ; Verburgh et al. Br. Sports Med. 2013;Epub Ahead of Print; Lee et al; et al. Psychoneuroendocrinology. 2014; 39:214-224; Drollette et al. Develop Cognitive Neuroscience. 2014;7:53-64

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.

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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.

Examples of Potential Benefits of Exercise for Children and Teens

Proposed Biological Mechanisms Affected by Exercise

Helps to enhances scholastic performance, and brain development and improve brain activation, especially in low-academic performers, compared to low-fit children

Helps to develop frontal cortex and medial temporal lobe (hippocampus) brain function for better memory forming, organizing and storing, cognitive control, and improved attention, accuracy and focus.

Helps to improve executive function mental processes that helps connect past experience with present action. It helps to support functions such as planning, organizing, strategizing, paying attention to and remembering details, and managing time and space.

Recent Aerobic Fitness and Cognition Research Highlights: Children & Teens

Research suggests that aerobic fitness can enhance brain connectivity and microstructure during neurodevelopment in fit children compared to their low fit peers (Herting et al. Develop Cog Neurosci. 2014; 7:65-75).

Study found that aerobic fitness facilitated cognitive performance in lower-performers who demonstrated the most improvements in response accuracy and focus measures following the end of exercise. (Drollette et al. Develop Cognitive Neuroscience. 2014; 7:53-64).

Study shows that compared to less fit children, highly fit children have larger sub-cortical brain structures, more efficient brain activation and neuro-processing during cognitive tasks, better working memory, attention and improved academic performance. (Haapala. J Human Kinetics.2013; 36:55-68).

Research finds that aerobic fitness during childhood enhances specific fMRI activation of brain frontal cortex function involved in cognitive control related to improved attention and focus. (Chaddock-Heyman et al. Frontiers in Human Neuroscience. 2013; 7(72):1-13).

Study found no differences in performance at initial learning between higher fit and lower fit participants. However, during the retention session higher fit children outperformed lower fit children. (Raine et al. PLOS ONE. 2013; 8(9): e72666).

Research reveals that exercise appears to improve the activation of brain neural circuitry supporting improved cognitive function in overweight children. (Krafft et al. Obesity. 2013; doi:10.1002/ oby.20518).

Findings show that a single bout of aerobic physical activity in the form of exergaming (active video games) enhances children’s executive decision making function across a wide age range compared to sedentary gaming. (Best. Developmental Psychology. 2012; 48(5):1501-1510).

Study suggests that daily moderate intensity walking is helpful for maintaining cognitive performance, with implication in scholastic performance. (Drollette et al. Med & Sci Sports & Exercise. 2012;44(10):2017-2024).

Research and a literature review suggest that aerobic fitness may influence brain health and cognition leading to enhanced scholastic performance and more effective cognitive function, which is important for adaptive behavior and cognitive development. (Hillman et al. Prev Med. 2011; 52S:S21-S28; Davis et al. Health Psychol. 2011; 30(10):91-98)

Findings show that higher-fit children have greater brain hippocampal volumes, efficiency of neural networks and enhanced relational memory performance compared to lower-fit children. (Chaddock et al. Brain Research. 2010;1358:172-183; Voss et al. Neuroscience.2011; 199:166-176)

Research provides evidence supporting the beneficial effects of regular exercise in improving memory and accuracy in teens. The beneficial effects were region-specific and associated with the serum levels of some neurotrophic factors. (Lee, et al. Psychoneuroendocrinology. 2014; 39:214-224).

Study shows that students in a moderately physical activity program improved overall performance on standard academic tests by 6% compared to a decrease of 1% for sedentary controls. (Donnelly and Lambourne et al. Preventive Medicine. 2011; 52:536-542).

Case Study #3: Aerobic Fitness Facilitates Brain Cognitive Function in Children

Background:To achieve high levels of cognitive control, children must be able to selectively attend to relevant information, filter distractions, and inhibit inappropriate response tendencies. Previous research shows that higher fit and physically active children have been found to outperform their lower fit peers on tasks of cognitive control. Only a few studies with children have used fMRI to examine how physical activity and aerobic fitness relate to brain function during tasks engaging cognitive control.

Methods: 23 8- to 9-year-old children, with pre-test and post-test fMRI data, were included in the

final analyses, with 14 children (7 female, 7 male) assigned to the physical activity intervention group and nine children (6 female, 3 male) assigned to the control group.

Children in the exercise group participated in a 60+ minute physical activity program, 5days per week, for 9 months and the control children did not participate in the program.

All children completed structural and functional-MRI scans.

Results/Conclusions: This study shows that physical activity during childhood may enhance specific elements of the frontal

cortex function involved in cognitive development and focus compared to children assigned to the non-fitness program (control) group.

These data support the role of aerobic exercise in healthy brain development.

Chaddock–Heyman et al. frontiers in Human Neuroscience. 2013;7(72):1-13

Case Study #1: Exercise Facilitates Brain Function and Cognition in Children Who Need It the Most

Background:Despite evidence that physical activity participation is associated with improved cognitive function, academic performance, and overall health in children, there continues to be a decline in the amount of time dedicated to physical activity during the school day. Studies focusing on single bouts of physical activity indicate that increasing the amount of time spent physically active may foster post-exercise cognitive benefits, which can help improve scholastic performance.

Methods: 40 healthy 8-10 year old children (27 females; 13 males) divided into two groups of 20

high performance and 20 low performance learners engaged in moderate-intensity aerobic activity and were than evaluated for cognitive performance.

These testing sessions were conducted following 20 minutes of either moderate intensity treadmill walking at 60–70% of maximal heart rate, or at quiet rest while seated in a chair that was safely placed on the same treadmill.

Cognitive function was assessed by computer based cognitive testing and neuroelectric assessments.

Results/Conclusions: Lower-performing students demonstrated an improvement in brain and cognitive function up to a level

similar to the high performers after the exercise bout . Higher-performing students maintained their cognitive performance levels after the exercise bout. The results suggested that short periods of physical activity during the school day are a means of regulating

attention in the classroom, especially among children who need it most. Drollette et al. Develop Cognitive Neuroscience. 2014;7:53-64.

Case Study #2: Study Suggest that Exercise Helps to Improve Cognitive Function in Teens

Background: The beneficial effect of aerobic exercise (exercise) on human cognitive functioning and mental well-being has been well documented. Recent findings have suggested that aerobic exercise may have a positive effect on teen brain functioning. Key brain regions affected are the (1) frontal cortex - planning complex cognitive behavior, personality expression, decision making, and moderating social behavior and (2) medial-temporal functions (hippocampus) - retention of sensory input processing, language comprehension, new memory storage, and emotions.

Methods: A total of 91 healthy teens (45 regular exercisers and 46 matched sedentary controls)

participated in this study. The exercisers were recruited from the Hong Kong Sports Institute where they received intensive training on rowing, swimming, running (>1000 m) or triathlon for at least two months prior to this study. A study design was adopted to compare cognitive functioning associated frontal and temporal brain regions and the serum levels of neurotrophic factors, brain signals known to improve brain function between the two groups.

Results/Conclusions: This study reports preliminary evidence of the beneficial effects of regular aerobic exercise in improving cognitive functions in teens. The exercising teens performed significantly better than the controls on the frontal and temporal functioning parameters, which are associated with the serum levels of neurotrophic factors. In associative learning . The exercisers had a higher memory score and accuracy than sedentary teens. Specifically, adolescent exercisers showed improved memory, inhibitory control, and cognitive flexibility. These findings suggest that chronic exercise would be associated with better performance in associative memory, the ability to learn and remember the relationship between unrelated items such as the name of someone they have just met.

Lee et al. Psychoneuroendocrinology. 2014; 39:214-224

“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