WEDNESDAY, Jan. 7 (HealthDay News) -- Health-related fitness is inversely associated with sedentary behavior and small-screen recreation among adolescent girls, but not boys, according to research published online Jan. 6 in the American Journal of Preventive Medicine.
Louise L. Hardy, Ph.D., of the University of Sydney in Camperdown, Australia, and colleagues surveyed a cross-sectional population of 2,750 students (grades 6, 8 and 10) during 2004. Using a self-report questionnaire, the investigators assessed the amount of sedentary activity and small-screen recreation each adolescent participated in. The cardiorespiratory endurance of each study participant was then determined using a 20-meter multi-stage shuttle run test. Results were analyzed using preset guidelines, which recommend less than two hours per day on small-screen recreation.
Girls in grades 8 and 10 who participated in two hours or more per day of small-screen recreation had a significantly lower cardiorespiratory endurance compared with those who spent less than two hours per day, the investigators found. While the same was true for grade 8 boys, this difference was not significant among boys in grades 6 or 10. The two hour/day guideline was found to be highly sensitive (79 to 84 percent) with low specificity (28 to 42 percent).
"This study provides health-related evidence to support the recommended guideline that young people spend less than two hours per day on small-screen recreation," the authors write. "However, further research, particularly longitudinal studies, is needed to understand the health-related effects of sedentariness among young people."
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