Recent Trends in Physical Inactivity Across Time
Many physically inactive behaviors have been and still are a fact of life—school
attendance, study, leisure reading, sitting and talking, etc. Technological advances
have added opportunities for physically inactive behaviors, and the pace of intro-
ducing technology has accelerated over time. More recent emphases on extracur-
ricular classes for music, art, and tutoring, among others, have also offered more
opportunities for physical inactivity (US Department of Education 2006 ).
Indicators of inactivity among youth have focused primarily on television
viewing and more recently computer use. Television viewing3 h/day among
American youth in the YRBS declined linearly from 1999 to 2009 with no change
to 2011; on the other hand, computer use (other than homework)3 h/day was
*22% in 2003 and 2005, increased to 25% in 2007 and 2009, and to 31% in 2011
(Centers for Disease Control and Prevention 2012 ). Boys consistently spent more
time using computers than girls. Percentages of youth 11–15 years from seven
European countries who watched at least 4 h television per day did not change
between 1986 and 1998. European boys also viewed television more than girls. Of
interest, vigorous physical activity and television viewing behaviors were not
correlated over this interval (Samdal et al. 2007 ). Similar trends were suggested
among youth in the UK and Australia (Dollman et al. 2005 ).
A comprehensive survey of“media”use among children and adolescents in the
USA highlights more recent changes in opportunities for physical inactivity asso-
ciated with technology (Rideout et al. 2010 ). After adjusting for multitasking, daily
time (h:min) devoted by American youth 8–18 years to media (television,
music/audio, computer, video games, print, and movies) was 6:21 in 1999 and 6:19
in 2004, but increased to 7:38 in 2009. Age-group-specific estimates of media use
time in 2009 are summarized in Table5.3. Talking on cell phones (0:33 per day)
was not included; listening to music or watching videos and playing games on cell
phones were included with the respective media types. Ownership of cell phones in
2009 increased with age: 8–10 years, 31%; 11–14 years, 69%; and 15–18 years,
Table 5.3 Age variation in daily time (h:min) spent with media by American youth in 2009
Media Age group, years
8 – 10 11 – 14 15 – 18
TV content 3:41 5:03 4:22
Music 1:08 2:22 3:03
Computers 0:46 1:46 1:39
Video games 1:01 1:25 1:08
Print 0:46 0:37 0:33
Movies 0:28 0:26 0:20
Total media exposure 7:51 11:53 11:23
% multitasking 30% 27% 30%
Total media use 5:29 8:40 7:58Adapted from Rideout et al. ( 2010 )
78 R.M. Malina et al.