There is an age-related decline in children's physical activity levels as they progress through primary school, according to a British Heart Foundation-funded study.
Researchers at the University of Bristol found that children spent less time doing physical activity and spent more time sedentary from Year 1 (aged 5-6) to Year 4 (aged 8-9).
Additionally, by the time they got to Year 4, around a third of boys and two thirds of girls aged eight to nine years old in the study were failing to meet Chief Medical Officer's (CMO) recommended physical activity guidelines of an hour of physical activity per day.
Previous research has shown that low levels of physical activity in childhood can track into adulthood, suggesting that we should be doing more to ensure children keep active throughout their younger lives.
In the study, published today in the International Journal of Behavioral Nutrition and Physical Activity, the researchers tracked the physical activity levels of 1,300 children in Year 1, aged 5-6, over a week.
To track the children, the team used an accelerometer, a smart device which gives an accurate measurement of movement. They then tracked the same children three years later, when they were in Year 4 (aged 8-9), and compared the results.
The levels of moderate-to-vigorous-intensity physical activity dropped by four per cent in boys, and eleven per cent in girls, but even more worryingly the sedentary time increased by 20 per cent in boys and 23 per cent in girls.
Further examination of the data showed that 62.3 per cent of boys and 35 per cent of girls met the CMO's recommendation of an hour per day in Year 4, compared with 72.5 per cent and 53.7 per cent respectively in Year 1.
Professor Russ Jago, Professor of Paediatric Physical Activity and Public Health at the University of Bristol, who led the study, said: "The results show a clear need to find ways to help children to be active throughout the primary school years. We need to get children active and then keep them active as they move through primary school.
"To help us to do this we need to find the activities that children enjoy and foster as many opportunities within and outside of school to take part in activity across the day."