<<Print>>

Limiting the time we spend sitting to just three hours a day could add an extra two years to our life expectancy, scientists calculate. Similarly, if we cut daily TV viewing down to two hours we could add on 1.4 years, they say in a report for the online journal BMJ Open. But experts say the US estimates, which are based on five separate population studies, are too unreliable to predict personal risk. Plus the targets are unfeasible. Prof David Spiegelhalter, an expert in risk calculations at the University of Cambridge, said: "This is a study of populations, and does not tell you personally what the effect of getting off the sofa might be. "It seems plausible that if future generations moved around a bit more, then they might live longer on average. "But very few of us currently spend less than three hours sitting each day, and so this seems a very optimistic target."