Authors:  Cheryl A. Howe, MS., and Patty S. Freedson, Ph.D., FACSM and PCPFS Science Board Member, Department of Kinesiology, School of Public Health and Health Sciences, University of Massachusetts, Amherst, MA

Introduction
The percentage of children 6 - 11 years of age who are overweight has more than tripled over the past three decades.  While childhood obesity continues to rise, physical activity levels in children continue to decline.  In a 2002 Youth Media Campaign Longitudinal Survey more than 3,000 children (9 - 13 y) were surveyed about their physical activity habits. The survey revealed that less than 40% of the children reported participating in organized physical activity while more than 20% reported no free-play activity outside of school hours.

The school is an ideal setting to increase physical activity through physical education, free-play activity during recess and in before- and after- school activity programs.  The National Association for Sport and Physical Education recommends at least 150 min/week of instructional physical education for elementary school children. The 2006 CDC’s School Health Policies and Programs Study revealed that only 4% of elementary schools provide daily physical education throughout the school year, a decline from 1991 when 42% of all children participated in daily physical education.1 

Physical activity, academic performance and cognitive development
Academic achievement is of critical importance for youth, and time devoted to learning in schools is central to its success.  However, factors other than time spent on core academic subject matter may also contribute to academic success.  Recent studies have shown that physical activity has a positive effect on academic performance. 3, 4, 9, 12, 13

Research has shown that the addition of physical education to the school day results in small but positive gains in academic performance.  Shephard and colleagues10, 11 added five hours of physical activity per week to 2nd to 6th grade classrooms (children 6 - 11 years of age).  In addition to improvements in cardiovascular fitness and strength, levels of arousal and attention in the classroom were better and overall academic grades improved for all grade levels.  Sixth grade standardized tests showed improvements in math and overall intelligence scores despite the 13-14% reduction in classroom studies due to the additional time allotted to physical activity. 

Other studies have shown that more time for physical activity does not hinder academic performance.  Dwyer and colleagues4 evaluated the addition of 75 min of PE in 500 10-yr old children.  After 3 years, no changes in academic performance were observed despite the reduction in time for formal teaching.  Similar results were reported following a 2 year physical activity intervention program (SPARK) for 4th and 5th grade children.9

Recent studies have shown positive associations between physical activity and cognitive function, particularly for executive function.5, 7, 8, 10, 11  Executive function, the ability to plan and select activities to organize goal-directed action and promote decision-making skills, is essential to psychological and social development in children.  Executive function influences a child’s ability to understand when to apply knowledge, effectively plan, update working memory, shift from one mental set to another, and inhibit impulsive behavior.  Improvements in any of these skills may aid in academic performance which is often measured by standardized tests and academic grades or estimated from measures of concentration, memory, and classroom behaviors. 

Functional magnetic resonance imaging (fMRI) scans of brain activity have been employed to characterize the underlying brain activity patterns linking physical activity, fitness and cognitive function.2, 3   In a study of 200 overweight 7 – 11 year old children, fMRI results revealed a positive dose-response between physical activity level and frontal-lobe brain activity, an important area for executive function during decision-making processes.  These beneficial changes in cognitive function corresponded with positive changes in standardized cognition test scores.3, 6 

Research evidence suggests that participation in daily physical activity in schools may improve academic performance.  Thus, the benefits of physical activity extend beyond the known health-related outcomes to include academic performance and cognitive function in children and should be viewed as a valuable part of each school day. 

References

1. National Association for Sport and Physical Education & American Heart Association. In: Shape of the nation report: Status of physical education in the USA. Reston, VA: National Association for Sport and Physical Education, 2006.
   
2. Colcombe, S. J., A. F. Kramer, K. I. Erickson, P. Scalf, E. McAuley, N. J. Cohen, A. Webb, G. J. Jerome, D. X. Marquez, and S. Elavsky. Cardiovascular fitness, cortical plasticity, and aging. Proc Natl Acad Sci U S A. 101:3316-3321, 2004.
   
3. Davies, C. L., J. Tkacz, P.D. Tomporowski. Effects of Aerobic Training Dose on Overweight Cheldren's Cognition and Achievement: A Randomized Controlled Trial. In North American Association for the Study of Obesity. New Orleans, LA, 2007.
   
4. Dwyer, T., W. E. Coonan, D. R. Leitch, B. S. Hetzel, and R. A. Baghurst. An investigation of the effects of daily physical activity on the health of primary school students in South Australia. Int J Epidemiol. 12:308-313, 1983.
   
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