Physical activity and screen time: trends in U.S. children aged 9-13 years, 2002-2006.
ABSTRACT We examined trends of physical activity and screen time among nationally representative samples of children aged 9-13 years to explore whether children overall are becoming less physically active and less likely to be in compliance with screen time recommendations.
We analyzed Youth Media Campaign Longitudinal Survey data for trends and demographic patterns of free time and organized physical activity, and hours and minutes of watching television and playing video or computer games. Child-parent dyads for 2002 (N = 3114), 2004 (N = 5177), and 2006 (N = 1200) were analyzed.
On the day before the interview, and for free time physical activity in the past week, children reported a significant increase in physical activity from 2002-2006. Screen time levels were stable overall; 76.4% of children met the recommendations of 2 hours or less of daily screen time.
Levels of physical activity among U.S. children aged 9-13 years were stable, or levels slightly improved from 2002-2006. Except for some subgroup differences, trends for compliance with screen time recommendations were also stable from 2002-2006 for U.S. children aged 9-13 years.
- [Show abstract] [Hide abstract]
ABSTRACT: OBJECTIVE:The high prevalence of adolescent obesity in the United States has been attributed to population changes in physical activity (PA), sedentary behaviors, and dietary behaviors. This study examines 8-year trends in these behaviors in US adolescents ages 11 to 16.METHODS:Nationally representative samples of US students in grades 6 to 10 were recruited during the 2001-2002 (N = 14 607), 2005-2006 (N = 9150), and 2009-2010 (N = 10 848) school years by using multistage stratified designs, with census regions and grades as strata, and school districts as the primary sampling units. African-American and Hispanic students were oversampled to obtain better estimates for those groups. Using the Health Behavior in School-aged Children quadrennial surveys, identical questions assessed BMI, PA, and sedentary and dietary behaviors at each school year. Logistic and linear regression analyses were conducted taking into account the sampling design and controlling for age, gender, race/ethnicity, and family affluence.RESULTS:Across the quadrennial surveys, significant increases were identified in number of days with at least 60 minutes of PA, daily consumption of fruits and vegetables, eating breakfast on weekdays and weekends, and BMI. Television viewing and consumption of sweets and sweetened beverages decreased across this same period. These same patterns were seen in all racial/ethnic groups.CONCLUSIONS:These patterns suggest that public health efforts to improve the obesity-related behaviors of US adolescents may be having some success. However, alternative explanations for the increase in BMI over the same period need to be considered.PEDIATRICS 09/2013; · 5.30 Impact Factor
- [Show abstract] [Hide abstract]
ABSTRACT: Studies in youth highlight that moderate-to-vigorous physical activity (MVPA) and screen-time behaviours such as television viewing and PC use are associated with a range of health outcomes. However, little is known about recent trends in these behaviours in adolescents. This paper presents time trends in German adolescents' television time, non-gaming PC use as well as MVPA from 2002 to 2010. Data were derived from the cross-sectional German Health Behaviour in School-aged Children (HBSC) study in 2002, 2006 and 2010. Analyses were based on 16,918 11-to 15-year olds boys (49.1%) and girls. Outcome variables were time spent in TV viewing and using a PC (weekday and weekend day) as well as the number of days achieving 60 minutes of MVPA. Changes in both screen-time behaviours and MVPA over time were analysed using sex-specific linear regression, controlling for age and family affluence. TV viewing on weekdays, but not at weekends, declined steadily over time with a difference between 2002 and 2010 of 12.4 min/day in girls and 18.3 min/day in boys (p for trend < .01). We found a strong increase in PC use for non-gaming purposes over time for girls only, with a difference between 2002 and 2010 of 54.1 min/weekday and 68.8 min/weekend day (p < .001). For MVPA we found a slight statistically significant increase in terms of meeting PA guidelines as well as days/week in MVPA for boys and girls (p < .001). In 2010 14.0% of girls and 19.9% of boys met PA guideline. Although MVPA increased from 2002 to 2010 in German adolescents, the time spent in MVPA was still low. Despite the observed decrease in TV viewing, there was no overall decline in the observed screen-based behaviours, especially for girls. This is mainly due to a marked increase in use of a PC for chatting on-line, internet, emailing, homework etc. among girls during the last ten years which outweighs the corresponding decrease in TV viewing. The findings highlight a need for strategies and interventions aimed at reducing screen-time behaviours and promoting MVPA.BMC Public Health 04/2014; 14(1):351. · 2.32 Impact Factor
- [Show abstract] [Hide abstract]
ABSTRACT: BACKGROUND: There has been an increase in screen-based communication, leading to concerns about the negative health effects of screen-based activities in children and adolescents. The present study aimed to (1) analyze changes in screen time activity in Norwegian children from 2001 to 2008, and (2) to analyze associations between the changes in screen time activity over time and sex, grade level and parental educational level. METHODS: Within the project Fruits and Vegetables Make the Marks (FVMM), 1488 6th and 7th grade pupils from 27 Norwegian elementary schools completed a questionnaire including a question about time spent on television viewing and personal computer use in 2001 and 1339 pupils from the same schools completed the same questionnaire in 2008. Data were analyzed by multilevel linear mixed models. RESULTS: The proportions of 6th and 7th grade pupils at the 27 schools that reported screen time activity outside school of 2 hours/day or more decreased from 55% to 45% (p<0.001) from 2001 to 2008 when adjusting for sex, grade level and parental education. The decrease was most evident in 6th graders (51% to 37%) and in children with highly educated parents (54% to 39%). CONCLUSION: The present study shows that there has been a marked reduction in screen time activity outside school in this group of Norwegian 10--12 year olds from 2001 to 2008.BMC Public Health 01/2013; 13(1):80. · 2.32 Impact Factor
Journal of Physical Activity and Health, 2012, 9, 508-515
© 2012 Human Kinetics, Inc.
Huhman is with the Dept of Communication, University of
Illinois at Urbana–Champaign. Lowry, Lee, Fulton, and Carlson
are with the National Center for Chronic Disease Prevention and
Health Promotion, Centers for Disease Control and Prevention,
Atlanta, GA. Patnode is with the Kaiser Permanente Center for
Health Research, Portland, OR.
Physical Activity and Screen Time: Trends in U.S. Children
Aged 9 to 13 Years, 2002–2006
Marian Huhman, Richard Lowry, Sarah M. Lee, Janet E. Fulton,
Susan A. Carlson, and Carrie D. Patnode
Background: We examined trends of physical activity and screen time among nationally representative samples
of children aged 9–13 years to explore whether children overall are becoming less physically active and less
likely to be in compliance with screen time recommendations. Methods: We analyzed Youth Media Campaign
Longitudinal Survey data for trends and demographic patterns of free time and organized physical activity, and
hours and minutes of watching television and playing video or computer games. Child-parent dyads for 2002
(N = 3114), 2004 (N = 5177), and 2006 (N = 1200) were analyzed. Results: On the day before the interview,
and for free time physical activity in the past week, children reported a significant increase in physical activ-
ity from 2002–2006. Screen time levels were stable overall; 76.4% of children met the recommendations of
2 hours or less of daily screen time. Conclusion: Levels of physical activity among U.S. children aged 9–13
years were stable, or levels slightly improved from 2002–2006. Except for some subgroup differences, trends
for compliance with screen time recommendations were also stable from 2002–2006 for U.S. children aged
Keywords: youth, tweens
Youth who engage in 60 or more minutes of physical
activity every day at a moderate to vigorous level of exer-
tion (MVPA) can experience important health benefits,
including strong bones, normal blood pressure, feelings of
well-being, and a healthy weight.1 However, many youth
do not achieve the recommended levels. Nationwide,
18.4% of high school students are physically active for 60
or more minutes every day.2 Most studies report that girls
are less active than boys and that youth are less physically
active as they age through adolescence.2–5
Some researchers hypothesize that low levels of
physical activity among youth are caused by excessive
screen time activities (eg, watching television, nonschool
computer use, playing video games). Most studies of this
displacement hypothesis are inconclusive.6–8 However, a
recent study among youth aged 9–15 years supports this
hypothesis and shows a negative association between
physical activity and screen time.9
Researchers identify other negative effects of screen
viewing activities, such as alcohol use,10 negative body
concept,11 and aggressive behaviors.12 In addition, obesity
is 3 to 4 times more likely among children with combined
high levels of screen time and low levels of physical
activity.13 The American Association of Pediatrics (AAP)
recommends that children older than 2 years be limited
to no more than 1 to 2 hours of quality programming
of entertainment media each day.14 Recent data from
NHANES show that more than 30% of children aged
6–15 years exceed the screen time recommendations.15
Given the concerns about the increasing prevalence
of obesity among children and adolescents during the
past 3 decades, it is important to assess whether levels
of physical activity and screen time among youth are
increasing, decreasing, or remaining stable over time.
We use national cross-sectional data to assess whether
progress is being made toward meeting the recommenda-
tions for youth physical activity and screen time usage.
Nationally representative data from 1999–2007 on high
school-aged youth from the Youth Risk Behavior Surveil-
lance System (YRBS) show that prevalence estimates for
regular participation in MVPA are unchanged for male,
female, white, black, and Hispanic U.S. high school stu-
dents.16 However, YRBS data trends for television (TV)
viewing improved during 1999–2007; the percentage of
high school students who reported limiting TV viewing
to 2 or less hours a day increased from 57.2% to 64.6%.16
U.S. studies that assess physical activity and screen
time trends among children younger than high school age
Trends for Youth PA and Screen Time 509
are limited to regional samples. For example, a survey
of Minnesota youth aged 11–15 years in 1997 and 2004
found no evidence of a decline in MVPA during these
years.17 The gap in data for national trends in physical
activity for U.S. children younger than high school age
led us to the current study. We report cross-sectional
trends in free time physical activity, organized physical
activity, and screen-viewing time for U.S. children aged
Data for this study are from the Youth Media Campaign
Longitudinal Survey (YMCLS), a telephone survey of
nationally representative samples of children aged 9–13
years and their parents.18 Independent samples of child-
parent dyads were surveyed in 2002, 2004, and 2006.
The sample sizes were different for each collection of
participants because the data were originally collected
to answer research questions related to the children’s
awareness of media messages and the effects these mes-
sages were having on their physical activity attitudes
and behaviors. Power analyses determined the samples
needed to address the research questions
All surveys took place during April–June in their
respective years and were conducted in English or Span-
ish, depending on the preference of the respondent. A
list-assisted, random-digit dialed (RDD) method was
used to select samples of households with telephones
in all 3 years. A 1-minute screener was used to identify
households with children aged 9–13 years. After con-
senting to participate and to have their child participate,
the parent completed a 12-minute interview that asked
about demographics and assessed their attitudes and
behaviors about their child’s physical activity. After the
children assented to be interviewed, they were asked
about their attitudes and behaviors related to physical
activity. We calculated overall response rates by multiply-
ing the household screening rate by the parent interview
completion rate and the child interview completion rate.
Additional information for sampling and weighting were
Each of the samples was weighted to population
totals for children aged 9–13 years, after preliminary
adjustments for differential probabilities of selection and
nonresponse. The 2002 sample was weighted to Census
2000 totals (http://factfinder.census.gov), whereas the
other 2 samples were weighted to the Current Popula-
tion Survey totals (www.bls.gov/cps). The median item
response rate for the YMCLS was more than 99%. To
facilitate weighting and analysis, items with missing data
were fully imputed by using a combination of hot-deck
procedures and regression modeling. The Centers for
Disease Control and Prevention’s institutional review
board approved this study.
Physical Activity Measures
Children were asked to report the physical activities
in which they had engaged during the previous 7 days
and whether each activity had a coach, instructor, or
leader, or if the activity was done during the child’s free
time. Children were asked to include activities that “got
your body moving,” such as sports or playing actively
with their friends, but to exclude physical activities
done during their school day. Children then reported
how many of the previous 7 days that they performed
the activity, and free time and organized sessions were
calculated by summing the number of days for all activi-
ties of the given type. Free time and organized physical
activity sessions were dichotomized as high active or
low active on the basis of the distribution of responses.
We used the following criteria: for free time physical
activity, participation in 3 or more free time physical
activity sessions in the past 7 days was considered high
active, whereas less than 3 free time physical activity
sessions was considered low active.
For organized physical activity, participation in 1 or
more organized physical activity sessions in the past 7
days was considered high active; less than 1 organized
physical activity session was considered low active. Chil-
dren were asked a yes or no question about whether they
had done any physical activities yesterday (ie, previous
day physical activity) and, if the response was yes, they
were also asked to name the activities. An independent
study was conducted to determine the reliability and
validity of the YMCLS items for measuring physical
activity among children aged 9–13 years. The results
showed acceptable test-retest reliability on reports of
physical activity and significant, moderate correlations of
those reports with detailed activity logs and data gathered
Screen Time Measures
Children were asked, “How many hours did you watch
TV, play video games, or play computer games yes-
terday?” Children were instructed not to include time
spent doing homework on the computer. The interviewer
recorded children’s responses in hours and minutes.
Children were categorized into 2 or less hours of screen
time and more than 2 hours of screen time on the basis
of AAP recommendations.14
Demographic information, including child’s age, sex,
and race/ethnicity; responding parent’s education level;
geographic census region; and urbanicity (a measure of
population density)20 were also measured.
510 Huhman et al
Trends of the prevalence of previous day physical
activity, free time physical activity, organized physical
activity, and screen time (ie, television viewing, video,
and computer games) were examined among all youth
and among specific subgroups of youth by sex, age, and
race/ethnicity. Linear and quadratic time variables were
created by using orthogonal coefficients that reflected the
biennial spacing of the surveys, and the variables were
simultaneously entered into logistic regression models
with demographic variables (ie, sex, age, race/ethnicity)
and variables controlling for census region, urbanicity,
and parental education.
Analyses were performed on data that had been
weighted to the national population census for the appro-
priate year by using SUDAAN (version 9.0, Research
Triangle Institute, Research Triangle Park, North Caro-
lina), a software package that accounts for the complex
sample design and weighting factors. Adjusted odds
ratios (OR) for main effects were considered statistically
significant if 95% confidence intervals did not include
1.0, and regression coefficients (betas) for trends were
considered statistically significant if P < .05. The pres-
ence of a significant linear time beta indicated an overall
increase (if the value was positive) or decrease (if the
value was negative) in the variable of interest over time. A
significant linear time beta accompanied by a nonsignifi-
cant quadratic time beta indicated the presence of linear
change. A significant quadratic time beta accompanied
by a significant linear time beta indicated the presence
of nonlinear change (ie, an acceleration, leveling off, or
change in direction) in addition to an overall increase
or decrease over time. A significant quadratic time beta
accompanied by a nonsignificant linear time beta indi-
cated the presence of nonlinear change with no overall
increase or decrease over time. A nonsignificant quadratic
time beta accompanied by a nonsignificant linear time
beta indicated the absence of any significant variation
in the data.
Sample sizes and demographic characteristics for all 3
cohorts are presented in Table 1. The number column (N)
refers to the unweighted sample size, and the prevalence
estimates are the weighted percentages.
The 2002 sample participants (Sample 1) were
interviewed in spring 2002. Eligibility screening was
completed with 61% of households. A parent completed
an interview in 88% of eligible households, as did 81%
of their children, yielding 3114 parent-child dyads. The
overall response rate was 43% (the product of the comple-
tion rates for the screening, parent, and child interviews).
In 2004, 5177 children and parent dyads were surveyed
(Sample 2); eligibility screening was completed in 59%
of households. Eighty-five percent of parents and 88%
of their children completed interviews, and 44% was the
overall response rate. For the 2006 survey (Sample 3),
eligibility screening was completed in 54% of house-
holds. Eighty percent of parents and 84% of their children
(n = 1200) completed interviews, and 36% was the overall
Physical Activity Characteristics—All
As shown in Table 2, when data were combined for all
3 years (2002, 2004, 2006) (n = 9491), demographic
subgroup patterns for children aged 9 to 13 showed that
females were less likely than males to report being physi-
cally active on the day before the interview (OR = 0.72)
and less likely than males to report engaging in 3 or more
free time physical activity sessions in the past week (OR
= 0.70; Table 2). There were no differences in organized
physical activity participation by gender.
African American (OR = 0.58) and Hispanic (OR
= 0.72) children were less likely than white children
to report being physically active on the day before the
interview; there were no differences among the race or
ethnic groups for reports of free time sessions of physical
activity in the past week. For organized physical activ-
ity, African American (OR = 0.61) and Hispanic (OR
= 0.72) children were less likely than white children to
report organized physical activity. There were minimal
or no age-related differences for physical activity on the
day before the survey for reports of 3 or more free time
sessions of physical activity in the past week, or for
participation in organized physical activity.
Trends for Physical Activity
There was an overall significant linear trend for the
percentage of children reporting being physically active
on the day before the survey, increasing from 60.5% in
2002% to 65.1% in 2006 (linear beta = 0.048, P < .05;
Table 2). Subgroup differences were found for gender
and age; linear trends for males and children aged 9 and
11 years were significant.
There was an overall significant linear trend and
quadratic trend for the percentage of children who
reported participating in 3 or more free time physical
activity sessions in the past 7 days. The prevalence of free
time physical activity did not change from 2002–2004,
but increased significantly from 2004–2006. Subgroup
differences were found for gender, age, and ethnicity.
Females and children aged 9 and 13 showed significant
linear and quadratic trends that mirrored the trends for the
group as a whole. White and Hispanic children showed
a linear increase in free time physical activity during the
4 years, as did children aged 10 years. There were no
changes during the 4 years of the study for organized
Screen Viewing Time Characteristics
Overall, 76.4% of children reported screen time of 2
hours or less per day (eg, watching TV, playing video
Trends for Youth PA and Screen Time 511
Table 1 Youth Media Campaign Longitudinal Survey Sample Characteristics; Sample 1—2002,
Sample 2—2004, and Sample 3—2006
Less than high school
High school graduate
Post college education
Town or exurban
Regions of the country
a Urbanicity is a variable that categorizes household in 5 categories on the basis of the zip code and developed by Claritas for the PRIZM data set.
games, or computer games). Females were more likely
(OR = 1.21) than males to meet the recommendation of
2 or fewer hours per day. Among racial groups, African
American children were less likely than white or Hispanic
children to meet the screen time viewing recommenda-
tion. The likelihood of meeting the screen time viewing
recommendation decreased as age increased.
The overall and age-specific prevalence of meeting
the screen time viewing recommendation was relatively
stable over time. Males (72.8% in 2002% to 76.9% in
2006; linear beta = 0.061, P < .05) and Hispanic chil-
dren (72.2% in 2002% to 81.0% in 2006; linear beta
= 0.116, P < .05) showed an improving trend, whereas
African American children showed a significantly wors-
ening trend (68.4% in 2002% to 56.3% in 2006; linear
beta = -0.138, P < .05). Some nonlinear variation was
detected among children aged 10 years.
Although it is generally accepted that physical activity
levels decline as children age through their preadolescent
and adolescent years, it is less clear whether children
are becoming less active over time. Our study provides
Table 2 Trends in Physical Activity and Screen Viewing Time Among Children Aged 9–13 Years
by Sex, Race/Ethnicity, and Age—United States, 2002–2006
Previous day physical activitya
Three or more free time physical
activity sessions, past 7 daysb
One or more organized physical
activity sessions, past 7 daysc
All years combined
Prevalence by year (%)
Linear% (95% CI)2006 Quadratic
62.6 60.562.165.1 0.048*0.012
67.965.6 66.272.0 0.075* 0.041*
evidence that children aged 9–13 years became slightly
more active during 2002–2006. During those 4 years,
small improvements were made in the prevalence of
being physically active during nonschool hours on the
previous day. In addition, the prevalence of engaging in
3 or more sessions of physical activity in their free time
during the past week increased. The improving trend for
previous day and for free time sessions was evident for
children aged 9–13 years as a whole with some subgroup
differences. For example, among Hispanic children, the
prevalence of 3 or more sessions of free time physical
activity in the past week increased from 62.7% in 2002%
to 72.2% in 2006.
We found that white, African American, and His-
panic children engaged in similar amounts of weekly
free time physical activity, but African American and
Hispanic children were less likely than white children
to report being physically active on the previous day. A
possible explanation for the discrepancy between these
2 variables for racial groups could be the lower engage-
ment in organized sports among African American and
Hispanic children, leading to lower levels of overall
physical activity being reported for “yesterday.”
An important finding in our study was that levels
of free time physical activity, reports of being physi-
cally active on the previous day, and organized sports
participation did not vary by age for these non-high school
children. For high-school-aged youth, physical activity
has been found to decrease each year from 9th–12th
grade.16 Some researchers have suggested that children
in their preteen years may show a marked drop in their
physical activity at some age point, but our findings
indicate that is not the case.
By using national data about organized physical
activity, our findings support regional studies showing
that girls and boys have similar levels of participation in
organized physical activities in their preteen years.21,22
Although equality among genders for organized physical
activities is positive, the disparities in organized physical
activities among African American and Hispanic chil-
dren compared with their white peers are striking. The
financial costs associated with physical activities and
transportation difficulties have been cited as barriers to
participation in physical activity by low-income parents.23
Our findings underscore the need to address these gaps
in affordable and accessible organized physical activity
programs for children in these demographic groups.
Our findings for trends in youth physical activity
are generally consistent with other studies. Lowry and
colleagues examined secular trends for physical activity
among high school youth and found that levels of moder-
ate and vigorous physical activity were unchanged from
Screen viewing time ≤ 2 hours
All years combined
Prevalence by year (%)
Linear% (95% CI) 2006Quadratic
76.475.5 76.876.80.014 –0.013
* Beta indicates logistic regression coefficient controlling for sex, race/ethnicity, age, geographic region, urbanicity, and parental education. OR
indicates odds ratio. CI indicates confidence interval. * P < .05.
a Nonschool physical activity (things that got your body moving like sports, physical activity lessons, or playing actively with your friends) on the
day before the survey.
b Nonschool physical activity (things that got your body moving like sports, physical activity lessons, or playing actively with your friends) done
in their free time in the past 7 days.
c Nonschool physical activity (things that got your body moving like sports, physical activity lessons, or playing actively with your friends) sessions
done with a coach, instructor, or leader in the past 7 days.
d Watching TV, playing video games, or playing computer games on the day before the survey.
Table 2 (continued)
514 Huhman et al
1999–2007.16 Patterns of youth physical activity in other
countries have also shown stability or slight increases.
For example, children aged 11, 13, and 15 years from 7
European countries showed generally stable trends of
vigorous physical activity from the mid-1980s to the
early 2000s.24 An increase from 136 minutes per week
in 1985 to 175 minutes per week in 2004 was observed
in cross-sectional surveys of Australian adolescents aged
Despite the popularity and variety of screen time
activities for youth, we found that children’s reports of
screen viewing time for the previous day were unchanged
over the 4 years for the group as a whole, but subgroup
differences existed. In all years combined, about 75% of
children aged 9–13 reported watching 2 or fewer hours
of television, video games, and computer games; females
were more likely than males to be at or under the 2-hour
recommendation. However, males showed a significant
improvement over the 4 years. Although age-specific
trends in screen time were unchanged during the 4 years,
older children were less likely than younger children to
meet the recommendation. For example, 13-year-olds
were significantly less likely (OR = 0.47) than 9-year-
olds to meet the recommendation, a finding congruent
with previous research.26 As has been found in other
studies,8,26 stark differences in screen time among race
or ethnic groups were evident with African American
children almost half as likely as white children to meet
the recommendation. African American children also
showed a worsening trend from 2002–2006. On the other
hand, the percentage of Hispanic children meeting screen
time recommendations improved during the 4 years,
matching the percentage of white children who met the
recommendation in 2006.
The lack of an overall change to the prevalence of
children meeting screen time recommendations from
2002–2006 may not necessarily reflect the total time chil-
dren are spending with media. Whereas total media use
may have remained the same over these years, children’s
exposure to multiple media channels and content is likely
changing. A recent study by the Henry J. Kaiser Family
Foundation showed that among youth aged 8–18 years,
29% of their time spent with media is spent multitasking
(ie, using 2 or more media concurrently).27 In addition,
how children interact with media is changing. The use
of digital recorders (eg, DVR, TIVO) allows users to
compress more content into less time. Thus, estimates
of the time youth spend with media may not completely
reflect how media use has changed over time, particularly
Strengths and Limitations
Our study has several strengths. The data are from nation-
ally representative samples of children aged 9–13 years,
an age group for whom nationally representative data
on trends for physical activity levels are very limited.
Although the data are self-reported, subject to social
desirability bias, and errors of recall that can be prob-
lematic, especially for younger children, the YMCLS
has been shown to provide reliable and valid estimates
of physical activity and screen viewing time.19 While
assessing screen time by asking children only about their
screen time “yesterday” is a limitation for studying trends
over time, similar measures of “yesterday” screen time
have been used in other large studies.27 Our study had
low response rates, and parents and children who agreed
to be in the study may not be representative of the U.S.
population; however, our unweighted sample distribu-
tion was very similar to that of our sample weighted to
the U.S. population. This suggests that our sample may
be broadly representative. In addition, the weights we
applied as part of the analysis included adjustments for
nonresponse and potential undercoverage, although the
weights cannot adjust for the potential bias introduced
if survey nonresponse or undercoverage were associated
with our variables of interest. Finally, we note that our
findings report cross-sectional trends and may not reflect
longitudinal trends over time.
Considering the small improvements in physi-
cal activity and the generally stable trend with screen
time viewing (African American children are a notable
exception), we can be cautiously optimistic that from
2002–2006, children in these preadolescent years held
their own against countervailing cultural forces that
were fostering sedentary lifestyles in children. The cul-
tural forces at work during recent years ranged from an
increase in television time in U.S. households27,28 and a
high number of children who have televisions in their
bedrooms (71%),29 to parents’ perceptions that their
neighborhoods are too dangerous to allow their children
to walk to school.30 These stable trends for physical activ-
ity and for screen time parallel the stability in prevalence
rates for high body mass index among U.S. children and
adolescents during 2003–2004 and 2005–2006, and the
lack of a significant trend for 1999–2006.31
This period also saw an increase in programs and
activities designed to encourage and support children’s
physical activity. One such national program was CDC’s
VERB campaign.32 VERB was a social marketing initia-
tive to encourage physical activity among children aged
9–13 years (approximately 21 million tweens). The
campaign ran from 2002–2006, and evaluation results
showed that throughout the life of the campaign, approxi-
mately 75% of tweens were aware of the campaign and
understood its messages. Those aware of the campaign,
about 17 million tweens, held more positive beliefs about
the benefits of physical activity than children unaware of
VERB and were significantly more physically active than
those unaware of the campaign. In addition, higher levels
of physical activity among those aware of the campaign
persisted into the later teen years.33
During this time, major commercial entities incorpo-
rated physical activity messages and programs into their
advertising and promotions. For example, for a short time,
McDonalds featured pedometers in their Happy Meals,
and Nickelodeon created a day-long tour and promotion
in U.S. cities entitled, “Let’s Just Play.” The National
Football League, in partnership with several national
nongovernment organizations, such as the United Way,
the American Heart Association, and Action for Healthy
Kids, now sponsors “Play 60,” a campaign dedicated to
Trends for Youth PA and Screen Time 515
getting all children to participate in 60 minutes of physical
activity daily. Given the present results regarding physical
activity, particularly free time physical activity, it appears
that programs such as these might have successfully
encouraged children of this age to adopt and maintain
The levels of physical activity among U.S. children aged
9–13 years were stable or slightly improved during the
years of the study, 2002–2006. Except for some subgroup
differences, trends for compliance with screen time rec-
ommendations were also stable from 2002–2006 for U.S.
children aged 9–13 years.
1. U.S. Department of Health and Human Services. Physical
activity guidelines for Americans. Washington, DC: U.S.
Department of Health and Human Services; 2008.
2. Centers for Disease Control and Prevention. Youth Risk
Behavior Surveillance—United States, 2009. Surveillance
summaries, June 4, 2010. MMWR. 2010;59(No. SS–5).
3. Troiano RP, Berrigan D, Dodd KW, Masse LC, Tilert
T, McDowell M. Physical activity in the United States
measured by accelerometer. Med Sci Sports Exerc.
4. Kimm SY, Glynn NW, Kriska AM, et al. Decline in
physical activity in black girls and white girls during
adolescence. N Engl J Med. 2002;347(10):709–715.
5. Kahn JA, Huang B, Gillman MW, et al. Patterns and
determinants of physical activity in U.S. adolescents. J
Adolesc Health. 2008;42(4):369–377.
6. Gorely T, Marshall SJ, Biddle SJ. Couch kids: correlates
of television viewing among youth. Int J Behav Med.
7. Ekelund U, Brage S, Froberg K, et al. TV viewing and
physical activity are independently associated with meta-
bolic risk in children: The European Youth Heart Study.
PLoS Med. 2006;3(12):e488 .
8. Roberts DF; Foehr, UG; Rideout, V. Generation M: Media
in the lives of 8–18 year-olds: The Henry J. Kaiser Family
9. Carlson SA, Fulton JE, Lee SM, Foley JT, Heitzler CD,
Huhman M. Influence of limit-setting in physical activity
on youth screen time. Pediatr. 2010;126(1):e389–e96.
10. Robinson TN, Chen HL, Killen JD. Television and music
video exposure and risk of adolescent alcohol use. Pediatr.
11. Harrison K. The body electric: thin-ideal media and eating
disorders in adolescents. J Commun. 2000;50:119–143.
12. Browne KD, Hamilton-Giachritsis C. The influence of
violent media on children and adolescents: a public-health
approach. Lancet. 2005;365(9460):702–710.
13. Laurson KR, Eisenmann JC, Welk GJ, Wickel EE, Gentile
DA, Walsh DA. Combined influence of physical activity
and screen time recommendations on childhood over-
weight. J Pediatr. 2008;153(2):209–214.
14. American Academy of Pediatrics, Committee on Public
Education. American Academy of Pediatrics: children,
adolescents, and television. Pediatr. 2001;107:423–426.
15. Fulton JE, Wang X, Yore MM, Carlson SA, Galuska DA,
Caspersen CJ. Television viewing, computer use, and BMI
among U.S. children and adolescents. J Phys Act Health.
16. Lowry R, Lee SM, Fulton JE, Kann L. Healthy People
2010 objectives for physical activity, physical educa-
tion, and television viewing among adolescents: national
trends from the Youth Risk Behavior Surveillance System,
1999–2007. J Phys Act Health. 2009;6(Suppl 1):S36–S45.
17. Nelson MC, Neumark-Stzanier D, Hannan PJ, Sirard JR,
Story M. Longitudinal and secular trends in physical activ-
ity and sedentary behavior during adolescence. Pediatr.
18. Potter LD, Judkins DR, Piesse A, Nolin MJ, Huhman M.
Methodology of the outcome evaluation of the VERB
campaign. Am J Prev Med. 2008;34(6S):S230–S240.
19. Welk GJ, Wickel EE, Peterson M, Heitzler CD, Fulton
JE, Potter LD. Reliability and validity of questions on the
youth media campaign longitudinal survey. Med Sci Sports
20. Claritas Corporation. Getting to know the 62 clusters:
cluster snapshots. Arlington, VA: Claritas Corporation;
21. Trost SG, Pate RR, Saunders R, et al. A prospective study
of the determinants of physical activity in rural fifth-grade
children. Prev Med. 1997;26:257–263.
22. Pedersen S. Urban adolescents’ out-of-school activity pro-
files: associations with youth, family, and school transition
characteristics. Appl Dev Sci. 2005;9:107–124.
23. Centers for Disease Control and Prevention. Physical
activity levels among children aged 9–13 years—United
States, 2002. MMWR. 2003;52(33):785–788.
24. Samdal O, Tynjala J, Roberts C, Sallis JF, Villberg J, Wold
B. Trends in vigorous physical activity and TV watching
of adolescents from 1986 to 2002 in seven European
countries. Eur J Public Health. 2007;17(3):242–248.
25. Okely AD, Booth ML, Hardy L, Dobbins T, Denney-
Wilson E. Changes in physical activity participation from
1985 to 2004 in a statewide survey of Australian adoles-
cents. Arch Pediatr Adolesc Med. 2008;162(2):176–180.
26. Sisson SB, Church TS, Martin CK, et al. Profiles of seden-
tary behavior in children and adolescents: the U.S. National
Health and Nutrition Examination Survey, 2001–2006. Int
J Pediatr Obes. 2009;4(4):353–359.
27. Rideout VJ, Foehr UG, Roberts DF. Generation M2: media
in the lives of 8–18 year-olds. The Henry J. Kaiser Family
28. Nielsen. “A2/M2 Three Screen Report 2009.” http://blog.
nielsen.com/nielsenwire. Accessed from: http://www.
tvturnoff.org/index. (Accessed June 17, 2010).
29. Davison KK, Lawson CT. Do attributes of the physi-
cal environment influence children’s physical activity?
A review of the literature. Int J Behav Nutr Phys Act.
30. Carver A, Timperio A, Crawford D. Playing it safe: the
influence of neighbourhood safety on children’s physical
activity—a review. Health Place. 2008;14(2):217–227.
31. Ogden CL, Carroll MD, Flegel KM. High body mass index
for age among U.S. children and adolescents, 2003–2006.
32. Wong FL, Huhman M, Heitzler CD, et al. VERB—A social
marketing campaign to increase physical activity among
youth. Prev Chronic Dis. 2004;1(3):A10.
33. Huhman J, Potter LD, Nolin MJ, et al. The influence of
the VERB campaign on children’s physical activity in
2002–2006. Am J Public Health. 2010;100(4):638–645.