Kids love TV - fact. Whether its watching trashy reality shows or playing computer games, it seems impossible to drag them away from the screen when it comes to getting them to do their homework. But it seems that just one extra hour per day spent watching TV, using the Internet or playing computer games could lead to poorer GCSE grades.

Research published in the International Journal of Behavioral Nutrition and Physical Activity by the University of Cambridge found that an extra hour over the average of four hours per day was associated with 9.3 fewer GCSE points at age 16 years – that’s the same as going from a B to a D.

The team studied 845 pupils, aged 14, measuring levels of activity and sedentary behaviour through heart rate and movement sensing, while assessing time spent in front of the screen, doing homework or reading for pleasure.

"We only measured this behaviour in Year 10, but this is likely to be a reliable snapshot of participants' usual behaviour,” says author Dr Kirsten Corder from the Centre for Diet and Activity Research (CEDAR) at the University of Cambridge.

The results suggest that although watching TV, playing computer games or being online were all associated with poorer grades, TV viewing was found to be the most detrimental, and although these result might not seem surprising, it’s the size of the impact that’s catching people’s attention.

“For each hour of screen, to get nine points lower is quite a big difference,” Corder says.

So our advice for anyone taking his or her GCSEs this year is to switch that telly off and maybe listen to some music or read a particularly informative and interesting magazine that you might have lying around (wonder what that could be…).

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