Children are feebler and less able to carry out physical activities than those born only a decade earlier, research shows.

Studies of more than 600 10-year-olds found that the number of sit-ups they could do fell by 27.1 per cent between 1998 and 2008. Arm strength dropped by 26 per cent.

In 1998, one in 20 children aged 10 was unable to support their own weight when hanging from wall bars, but the proportion incapable of doing so had risen to one in 10 by 2008. The study, published in the journal Acta Paediatrica, has renewed concern about the sedentary lifestyles of many British children.