1. Aerobic Exercise Training Improves Overweight Children’s Behavior in the Classroom
Catherine L. Davis, Ph.D.1
Joseph Tkacz, M.S.1
Mathew Gregoski, M.S.2
Colleen Boyle, M.S.1
Catrina Creech, B.A.1
Phillip Tomporowski, Ph.D. 2
1Georgia Prevention Institute
Department of Pediatrics
Medical College of Georgia
2University of Georgia
Department of Kinesiology

2. Childhood Obesity
Childhood obesity is an epidemic with major implications (Strauss et al., 2001)
Inactivity is a major contributor
Overweight children are at risk for poor academic achievement (Dwyer et al., 2001; California Department of Education, 2005)
However, the mechanism is unknown.

3. Exercise & Cognition: EXECUTIVE FUNCTION
Meta-analysis indicates that physical activity improves executive function in older adults. (Colcombe & Kramer, 2003)
Meta-analysis supports a similar effect of exercise on executive function in children. (Sibley & Etnier, 2003)

4. Classroom Behavior reflects Executive Function
The Conners Teacher Rating Scale was selected as a behavioral index of executive function that is relevant to educational outcomes.
Barkley conceptualizes attention-deficit disorder as a developmental delay in executive functions (Barkley, 1997)
behavioral inhibition
self-regulation of arousal
working memory

5. Physical Activity and Classroom Behavior
Adverse effects of physical activity on children’s classroom behavior have not been demonstrated
that it would fatigue children
or hyperstimulate them
A study examining the impact of recess on classroom behaviors revealed that children worked more on task and fidgeted less on days they were offered a recess period (Jarrett et al., 2001)

6. Purpose of Study Hypothesis
To test the hypothesis that physical activity may improve overweight children’s behavior in the classroom
Children assigned to an exercise program will improve in classroom behavior relative to controls
Exercise > controls
Hypothesis

7. Methods
Sample consisted of 123 healthy but overweight, sedentary children (Table 1)
Recruited from local elementary schools in the Augusta area
Age range 7-11 yrs
BMI Percentile >= 85
Excluded data for subjects who did not attend posttest
Included children on ADHD medication (n = 8)

8. RANDOM ASSIGNMENT Baseline Testing
$100 Savings Bond for subjects who complete pretest
(blood tests etc.)
RANDOM ASSIGNMENT
Lifestyle
class only
Exercise program
(20 or 40min/d)
Post-Testing
$400 Savings Bond for subjects who complete posttest

9. Table 1. Sample Characteristics
Control Condition
Exercise Condition n 42 81
Age (years)
9.5 ± 1.1
9.3 ± 1.0
BMI Z-Score
2.1 ± 0.4
BMI %ile
98 ± 3
Boys
Girls
31%
69%
48%
52%
Whites
Blacks
40%
60%
41%
59%

10. After School Exercise Program
Every day after school for weeks
20-40 min of aerobic exercise per day
Transportation provided (school bus)
Vigorous aerobic activities (running games, jump rope, basketball) (Gutin et al., 1999)
Competition, skill deemphasized
Incentives for goal achievement:
Attend at least 4 days/week
Average daily heart rate > 150 bpm
Approximately 1 staff member per 9 children

11. Teacher Rating Scale
Conners Teacher Rating Scales-Revised Short (CTRS:RS) is a 28 item report of ADHD and related conduct problems in the classroom (Conners, 1997)
T-scores normed by age and sex
Good reliability (Tables 2 & 3 from manual)
Yields 4 discrete scales
Oppositional: high scorers likely to break rules, have trouble with authority, and are easily angered
Cognitive Problems/Inattention: high scorers tend to have trouble concentrating, learn more slowly, and have difficulty completing schoolwork
Hyperactivity: high scorers have difficulty sitting still or remaining on the same task for very long; are very restless and impulsive
ADHD: used to screen children for ADHD

12. Conners Sample Items Oppositional Scale
A Little True
Pretty Much True
Not True
Very True
Oppositional Scale
2. Defiant………………………………………………
10. Spiteful or vindictive……………………………
Cognitive Problems/Inattention Scale
14. Short attention span……………………………
23. Interrupts or intrudes others……………………
Hyperactivity Scale
18. Lacks interest in schoolwork……………………
27. Excitable, impulsive……………………………
ADHD Scale
5. Disturbs other children……………………….……
17. Has difficulty waiting turn………………………

13. Oppositional Defiance Oppositional Defiance
Conners Reliability
(Conners, 1997)
Table 2. Cronbach’s α
Oppositional Defiance
Cognitive Problems
Hyper-Activity
ADHD Index
6-8 yrs.
Males
Females
.87
.88
.92
.95
.96
.94
9-11 yrs.
.89
Table 3. Test-retest reliability
Oppositional Defiance
Cognitive Problems
Hyper-Activity
ADHD Index
rxx
.84
.92
.72
.80

14. Results
ANCOVA tested the effect of exercise on Conners scales, adjusted for pretest scores.
A planned contrast showed that children in the exercise conditions had lower adjusted posttest scores on the Cognitive Problems/Inattention scale (Adjusted Mean = 51.8, SE = 0.7) vs. controls (Adjusted Mean = 54.6, SE = 0.9; p < .05).
Excluding children on ADHD meds did not affect results (p < .05).
No significant effects of exercise were found on other Conners scales.

15. Scales ____________________________
Table 4. Exercise vs. control means (SD) on Conners
Conners Exercise
Scales ____________________________
Pre Post Diff.
Oppositional (11.0) (11.3) (7.7)
Cog. Problems (11.2) (9.9) (6.0)
Hyperactivity (9.9) (10.1) (7.4)
ADHD Index (12.8) (12.1) (7.7)

16. ______________________________
Teacher Rating Scales at pre, post, and changes
Control ANCOVA
______________________________
Pre Post Diff Sig.
50.7 (7.3) (10.0) (10.4) p = .296
52.5 (10.0) (12.1) (7.0) p = .019*
51.0 (8.5) (8.3) (9.1) p = .765
53.4 (10.8) (11.6) (9.9) p = .078

17. Changes (SD) on Conners Scales
p < .05
Cognitive Problems
Hyper-activity
ADHD Index
Opposition

18. Discussion
Exercise program caused greater improvements in classroom behavior in comparison to controls, who worsened
This effect was specific to the Cognitive Problems/Inattention scale of the Conners Teacher Rating Scale
This is consistent with an exercise effect improving executive function

19. Limitations Data collection is not yet completed.
Teachers may have been aware of which group children were randomized to, therefore we cannot rule out bias.
Comparison with a no-exercise control condition does not rule out possible effects of enrollment in a quality after-school program.
Attention from staff, removal from TV and similar mind-numbing pursuits may have an effect.

20. Possible Mechanisms
6 mo of aerobic training (walking 3x/wk) in sedentary older adults vs. controls led to changes in brain activation in frontal lobes corresponding to improvements on tests of executive function. (Colcombe et al., 2004)
The executive control and altering networks of the brain are rich in dopamine receptors, and are believed to be involved in the inattention aspect of ADHD (Swanson et al., 2000; see Dishman et al., 2006)
Physical activity enhances brain dopamine synthesis (Sutoo et al., 1996), which can affect brain function and influence behavior

21. Public Health Implications
Regular, aerobic exercise may be an effective way of improving the classroom behavior of overweight, sedentary children.
Exercise is simple, inexpensive, and promotes general good health.
Physical activity during and after school (PE, recess, etc) might promote academic achievement.

22. NIH Funding This study was supported by grants:
R01 DK60692 & R01 DK70922 (Davis)