The physical activity among children in the United States declines sharply as they age leading to their becoming obese adults, a US study has found. Researchers said moderate-to-vigorous physical activities of children decreases by greater than one-third as they aged from nine to 15.
The researchers found that at the age of nine children are engaged in about three hours of moderate-to-vigorous physical activity per day on both weekdays and weekends.
By the age of 15, the time was reduced to only 49 minutes per day during the week and 35 minutes on weekends, much less than the recommended time of 60 minutes per day.
“While we all knew children and youth were moving less, the magnitude of the rate of decline calls for renewed action to increase activity levels in the population,” said Philip R. Nader, the lead author and a professor emeritus at the San Diego School of Medicine.
“Physical activity is a crucial part of the energy equation; declining physical activity will only complicate the obesity epidemic,” the Nader said.
The study measured the physical activity of more than 1,000 youths in ten cities, beginning in 2000, when the children were nine-year-old and ending in 2006, when they reached 15 years of the age.
During the study, the physical activity of children was measured using an “accelerometer” which records minute-by- minute movement counts.
At four different stages (at the age of 9, 11, 12, 15), participants wore the monitor on a belt around the waist during waking hours for a total of five weekdays and two weekend days. This excluded showering, bathing, water sports or contact sports.
The study also showed that boys were more active than girls. They spend 18 more minutes per weekday and 13 more minutes per weekend day in moderate-to-vigorous physical activities than girls.
However, the rate of decline as they aged was the same for boys and girls. “Programme and policy action are needed immediately at the family, community, school, health care, and governmental levels to find ways to encourage children to remain active as they get older,” said co-author Renate Houts
Researchers recommended that parents and care givers start early, by providing safe places, preferably out doors, in which to engage in active play. “To foster the necessary culture and environment for activity, adults will have to become role models for children and youth, stressing activity and exercise for enjoyment and fun rather than drudgery or punishment,” said Nader.
According to statistics from National Institutes of Health surveys, in the past two decades the prevalence of overweight children in the US has increased from 6.5 per cent to 18.8 per cent.