Half of six-year-olds in England do not get enough exercise each day, according to a study.
Only 53 per cent do the 60 minutes of vigorous exercise recommended by the NHS for the age group — with girls doing less than boys.
This can include playing in the park, games in PE at school and sports like football or tennis.
Regular exercise is vital for strengthening muscles and bones during children’s development and also in fighting off obesity.
It comes amid a growing childhood obesity epidemic that means one in five youngsters in England are too fat by the time they start primary school.
Childhood obesity reached ‘unprecedented levels’ during the Covid pandemic, with children sat at home and not able to run around in playgrounds.
Primary school children saw their average screen time on tablets and phones boom during the pandemic.
Researchers from the universities of Cambridge and Southampton found only 53 per cent of six-year-olds got an hour of exercise including playing in the park or PE per day
NHS figures reveal ever-growing obesity trend reversed last year
Childhood obesity levels have dropped back in line with pre-Covid trends, official data has suggested.
Over one in five youngsters (22.9 per cent) who started school in September 2021 were overweight or obese in England.
This was down from nearly three in 10 (27.7 per cent) the year before, which was an ‘unprecedented’ rise and blamed on the knock-on effects of closing schools.
Experts called today’s update ‘good news’, after obesity levels reach all-time highs last year after successive Covid lockdowns.
Rates also dropped in overweight children, reducing from 40.9 per cent to 37.8 per cent.
The measure for the Year 6 age group, which is only a preliminary estimate, is still up on levels recorded before Covid. But younger age groups are now below previous marks.
It comes after a study yesterday revealed the number of healthy children choosing to diet has tripled in the last two decades.
An Oxford University study discovered more than a quarter of children are on diets, including those of a healthy weight.
The latest study by the universities of Cambridge and Southampton, tracked exercise levels in 712 children.
Results have been published in the Journal of Physical Activity and Health.
Children were given a device to wear on their chest that measures heart rates and movement for six days at age four and six.
They went to school and about their daily lives while wearing the devices.
The device gave readings every hour, allowing researchers to see how their exercise levels varied through the school day.
Children were sedentary for a daily average of more than five hours and 16 minutes.
They engaged in seven hours and 37 minutes of low-level physical activity.
But just under half (47 per cent) did not get the recommended hour of moderate-to-vigorous physical activity.
They found 63 per cent of boys hit the one-hour target, compared to just 42 per cent of girls.
The team say it could be because girls wear skirts, which may make physical activity more challenging, or that they choose less active options during break times.
Children were also sedentary for more than five hours on average, preferring activities like watching TV and playing video games.
Lead author Dr Esther van Sluijs, a behavioural epidemiologist at Cambridge University, suggested the children not getting enough exercise may suffer at school as a result.
She said: ‘Using accelerometers, we were able to get a much better idea of how active children were.
‘We found that just over a half of six-year-olds were getting the recommended amount of physical activity.
‘But this means that almost half of British children in this age group are not regularly active, which we know is important for their wellbeing and their performance at school.’
When the researchers analysed activity levels by time of day, they found girls did less ‘moderate-to-vigorous physical activity’ during the school day.
The researchers were able to look at data recorded over a period of time, rather than just a snapshot, for some children.
They found that compared to at age four, six-year-olds became spent 30 minutes more time doing sedentary activities.
But they also engaged in an additional seven minutes per day of moderate-to-vigorous physical activity.
Office for National Statistics (ONS) data shows the number of obese or morbidly obese children starting or finishing primary school fell in May 2022 in England
Obesity is still more prevalent in boys than girls across both age groups. For reception-age children this year, 10.6 per cent of boys were obese compared to 10.2 per cent of girls. Among year 6 pupils, 26.5 per cent of boys were obese compared to 20.3 per cent of girls
Demand for care for those with type 2 diabetes at paediatric diabetes units across England and Wales has increased by 57 per cent. Children being treated at the units jumped from 621 in 2015/16 to 973 in 2020/21
Dr Kathryn Hesketh, of the MRC Epidemiology Unit at Cambridge, said: ‘This is something of a double-edged sword.
‘Children appear to do more moderate-to-vigorous physical activity when they start formal schooling, which is really positive, but they also spend more time sedentary.
‘This may in part be because of the structure of the school day, so we may want to look at ways to reduce sedentary time when children are younger, to prevent that behaviour becoming habitual.’
Professor Keith Godfrey, from the University of Southampton, said: ‘These analyses indicate that new initiatives to promote physical activity must consider the lower activity levels in girls and at weekends.
‘The time when children transition into formal schooling is an important opportunity to ensure a much higher proportion achieve recommended levels of activity.’