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Educating the Student Body
FIGURE 2-6 
Approximate number of hours spent during the day at different levels of energy 
expenditure.
SOURCE: Treuth et al., 2012. 
Figure 2-6.eps
0
3
6
9
12
15
Hours Awake During Day
Sedentary-Intensity
Physical Activity
Light-Intensity
Physical Activity
About 3 hrs/day
vigorous-
or moderate-
intensity
physical
activity
About 1 hr/day
vigorous-
or moderate-
intensity
physical
activity
Sedentary-Intensity
Physical Activity
Light-Intensity
Physical Activity
Data from the YRBS and the NHANES are the most frequently cited. 
Based on accelerometer-assessed physical activity, youth aged 6-19 engage 
in sedentary physical activity 6-8 hours per day (Matthews et al., 2008) (see 
Figure 2-7). Figure 2-7 also provides estimates of the average time per day 
spent using different types of media (TVB, 2012). Reports from the YRBS 
suggest that about one-third of both middle and high school students report 
watching television for at least 3 hours per day. In response to a different 
question, those in this age group (not necessarily the same students) report 
using a computer for at least 3 hours per day (CDC, 2012b). Other reports 
(Anderson et al., 2008; Sisson et al., 2009; Wright et al., 2009) and a review 
(Pate et al., 2011) are available. Data from two reasonably comparable 
studies demonstrate the reduction in vigorous- or moderate-intensity physi-
cal activity and the rise in sedentary and light-intensity activity as girls grow 
from age 5 to 8 to 12 (Janz et al., 2005; Pate et al., 2006b) (see Figure 2-8).

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Copyright © National Academy of Sciences. All rights reserved.
Educating the Student Body: Taking Physical Activity and Physical Education to School
Status and Trends of Physical Activity Behaviors and Related School Policies
 
57
FIGURE 2-7
Hours per day spent in sedentary activity by age group, ages 6-19, and hours 
per day using different media sources, ages 13-17.
NOTE: NHANES = National Health and Nutrition Examination Survey.
SOURCES: Matthews et al., 2008; TVB, 2012.
Figure 2-7.eps
0
1
2
3
4
5
6
7
8
9
Hour
s 
per 
Da
y
2003-2004 NHANES
Accelerometer, Matthews (2008)
6-11 Year
s
12-15 Year
s
16-19 Year
s
TV
Newspaper
Radi
o
Magazines
Internet
Tablet
Mobile Phone
TV Basics (2012)
FIGURE 2-8
Percentage of waking hours spent in sedentary, light, moderate, and vigorous 
physical activity by girls aged 5 and 8 (all from Iowa) and aged 12 (from Arizona; California; 
Louisiana; Maryland; Minnesota; South Carolina; and Washington, DC).
SOURCES: Janz et al., 2005; Pate et al., 2006b.
Figure 2-8.eps
0
20
40
60
80
100
5 Years
8 Years
12 Years
P
ercentage of 
W
aking Hours
Vigorous
Moderate
Light
Sedentary 

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Copyright © National Academy of Sciences. All rights reserved.
Educating the Student Body: Taking Physical Activity and Physical Education to School
58