Electronic media exposure and its association with activity-related outcomes in female adolescents: cross-sectional and longitudinal analyses.
BACKGROUND
Few investigations have assessed in adolescent girls the cross-sectional and longitudinal associations between elevated exposure to electronic media (EM) and activity-related outcomes such as compliance with physical activity (PA) standards or cardiorespiratory fitness (CRF).


METHODS
Four-hundred thirty-seven white and African American girls were assessed at the 8th, 9th, and 12th grades. PA and EM (TV/video watching, electronic games, Internet use) were self-reported, and CRF was estimated using a cycle-ergometer test. Hi EM exposure was defined as >or=four 30-minute blocks/d.


RESULTS
8th-, 9th-, and 12th-grade girls in the Hi EM group showed lower compliance with PA standards and had lower CRF than the Low EM group (P<or=.03). Girls reporting Hi EM exposure at 8th and 9th grades had lower vigorous PA and CRF levels at 12th grade than girls reporting less EM exposure (P<or=.03).


CONCLUSIONS
Girls reporting exposure to EM for 2 or more hours per day are more likely to exhibit and maintain low PA and CRF levels throughout adolescence. These results enhance the scientific basis for current public health recommendations to limit adolescent girls' daily exposure to television, electronic games, and Internet use to a combined maximum of 2 hours.
Lobelo
Felipe
F
Department of Exercise Science, Arnold School of Public Health, University of South Carolina, Columbia, SC 29208, USA.
Dowda
Marsha
M
Pfeiffer
Karin A
KA
Pate
Russell R
RR
D000293:Adolescent; D003201:Computers; D003430:Cross-Sectional Studies; D005260:Female; D007722:Health Knowledge, Attitudes, Practice; D006293:Health Promotion; D006801:Humans; D020407:Internet; D008137:Longitudinal Studies; D008402:Mass Media; D009043:Motor Activity; D017063:Outcome Assessment, Health Care; D010809:Physical Fitness; D013690:Television; D013997:Time Factors