A survey of eight to 10-year-olds has found they are spending just 20 minutes a day being active when the recommended figure is an hour.
By the age of eight, girls are already becoming more sedentary than boys – a phenomenon previously noted in secondary school – and it could be due to a belief that sport is not ‘cool’.
New research indicates more must be done to get children active and to avoid an obesity crisis.
Female role models such as Olympic hopeful Jessica Ennis could help the problem.
More than 500 eight to 10-year-olds wore activity monitors which gave analysts an accurate picture of how little time children spent exercising.
They were monitored for a range of actions from moving around, climbing stairs to running, playing games and skipping.
It revealed children spent only 4 per cent of awake time in moderate to vigorous intensity physical activity, about 20 minutes per day, while the recommended amount for health is 60 minutes per day.
At the age of eight, girls were already less active than boys, which surprised researchers as the change happened earlier than previously thought.
Older fathers tended to have less active children – possibly as a result of having more senior roles at work and less free time, or perhaps as they had a traditional, less hands-on view of parenting.
Children who took part in sports clubs outside of school were significantly more active than those who did not.