Half of all seven-year-olds do not get enough exercise – and girls are far less active than boys, research shows.
Only 51 per cent of all seven-year-olds in the UK achieve the recommended hour of exercise every day, with the figure being just 38 per cent in girls compared with 63 per cent in boys.
Half of this age group is also sedentary for an average of 6.4 hours or more every day, experts found.
The research, published in the online journal BMJ Open, found that children of Indian origin and those living in Northern Ireland are among the least physically active of all seven-year-olds.
Experts including from the University College London’s Institute of Child Health examined data for 6,497 children.
The youngsters wore an accelerometer to measure exercise levels which was attached to an elastic belt round their waist. It was only removed when bathing or when the children went to bed.
In total, the experts were able to record 36,309 days of data based on the children wearing the accelerometer for at least 10 hours a day over the course of a week.
The analysis showed that on average, across the entire sample, children managed the recommended 60 minutes of moderate to vigorous physical activity every day, and that they took an average of 10,299 steps.
But half the children were sedentary for six or more hours every day, and half did not reach the daily recommended exercise target.
Girls were more sedentary and less active than boys while only one in three (33 per cent) children of Bangladeshi origin met the recommended daily exercise minimum.
Among the four UK countries, children in Northern Ireland were the least active, with just 43 per cent managing the recommended 60 minutes, while children in Scotland were most likely (52.5 per cent) to achieve the target.
Around 52 per cent of all children in England managed the 60 minutes but there were regional differences. Those living in the North West were the most likely (58 per cent) to hit the target, and those in the Midlands the least likely to do so (46 per cent).
The researchers said more needs to be done to boost the amount of exercise children are doing, including promoting walking or cycling to school.
They said: “The results of our study provide a useful baseline and strongly suggest that contemporary UK children are insufficiently active, implying that effort is needed to boost physical activity among young people to the level appropriate for good health.”