Physical activity is associated with improved psychological well-being and lower levels of cardiometabolic risk factors among children and adolescents. However, several studies have shown that physical activity declines, and sedentary time increases in an approximately linear fashion between ages 6 and 15, with girls less active than boys across all age groups.
As a result, large proportions of older children are not engaging in the recommended 60 min per day of moderate-to-vigorous-intensity physical activity (MVPA). Examining patterns of physical activity across childhood is significant for identifying key ages in which to intervene to change behavior.
A new study aims to examine the association of body mass index (BMI) with a change in children’s physical activity and sedentary time between ages 6 and 11.
Almost 2,000 children were recruited from 57 schools across South West England during primary school. They were asked to wear an accelerometer for five days, including two weekend days, which provided an accurate assessment of how many minutes per day the children participated in moderate to vigorous physical activity (MVPA) – enough to get them slightly out of breath and sweaty.
Scientists found that children tend to become 17 minutes less active per week every year. Sixty-one percent of children in Year 1 did at least an hour of MVPA per day, but by Year 6, only 41 percent achieved the target. The drop was particularly steep for girls, who fell from 54 to 28 percent by the time they finished primary school.
Russ Jago, Professor of Paediatric Physical Activity & Public Health at the University of Bristol, said, “These numbers prove that more needs be done to ensure children keep active as they approach adolescence. This isn’t about getting children to exercise more, but rather maintaining their activity levels. Developing early intervention strategies that help children retain activity levels could include after school physical activity programs, focusing on participation and enjoyment in addition to popular sports – and a greater emphasis on promoting weekend activities.”
Professor Jeremy Pearson, BHF’s Associate Medical Director, said: “Almost a third of children in the UK weigh more than they should, while one in four primary school children are not meeting the recommended levels of exercise.
“We know that children living with obesity are more likely to become obese adults – putting them at increased risk of developing heart and circulatory diseases and their risk factors, such as type 2 diabetes and high blood pressure, later in life.
“Staying active must be combined with policies that help families make healthy and informed choices, such as a 9 pm watershed on junk food marketing and restricting the promotion of unhealthy foods.”
The study is published in the International Journal of Obesity.