Girls who spend more than two hours of "screen time" a day watching television, surfing the Web or text messages are less likely to be physically fit, a new Australian study.

Interestingly, boys who were part of the study were more likely to be able to sit down and stay in shape, "said lead author Louise Hardy, a postdoctoral fellow at the Center of New Wales South overweight and obesity, University of Sydney.

boys, especially older adolescents May be less affected by the time they spend watching television, playing computer games and other activities on a small screen, because its growth has given rise to advanced enough to maintain muscular fitness, and even participate in a large number of sedentary behavior, the study suggests.

boys are also more likely to play sports and games, "said Dr. Goutham Rao, clinical director of the Weight and Wellness Center at boy's Hospital of Pittsburgh. A teenager who is on the swim team, for example, can spend time playing video games like World of Warcraft, "he said.

"There is a culture of physical fitness among boys, and there is a culture of sedentary activity," he added.

From his experience, Rao said, "there are only a small group of teenagers who engage in regular physical activity." He added that he believes the center of adolescence are more interested in the small screen, communication devices, such as text, as in video games.

Researchers from Australia said that his study in May was the first to combine the "sedentary" - a measure of fitness cardio-respiratory system - widely accepted in the American Academy of Pediatrics guidelines for boys 2 to 18 spend more than two hours andalusia day on television, leisure.

"This is important because it ensures a good level of fitness cardio-respiratory system can reduce the risk of developing cardiovascular disease," said Hardy. For the study, researchers measured the fitness of cardio-respiratory number of laps to run a set pace.

The study, based on data collected in 2004, activity is defined as a small screen to watch TV, videos and computer use for leisure. The data comes from a survey of a representative sample of 2,750 students in sixth, eighth, and 10 degrees.

More current data can be even more surprising that the growth of new display technologies such as Xbox, PSP, and WIIS, Hardy suggested. The impact of new technologies to the small screen can display a repetition of the survey, scheduled for 2010, he said.

The results were published in the February issue of the American Journal of Preventive Medicine.

The researchers said the study was limited in its ability to make a causal link between the small screen and less time for physical activity, because other factors May be involved.

The question of whether girls are less physically more likely to participate in sedentary Rao is one of those who said he would like to see in future research.