Amount of physical activity by children steadily declines as they get older

Jul 15, 2008

New research documents the decline in physical activity among children, with less than a third meeting recommended physical activity guidelines by the time they are 15 years old, according to a study in the July 16 issue of JAMA.

Physical inactivity is associated with an increase in obesity and associated illness and chronic diseases among youth. Expert opinion and studies suggest that children need a minimum of 60 minutes of moderate-to-vigorous physical activity (MVPA) per day, according to background information in the article. How many youth meet this standard is unclear.

Philip R. Nader, M.D., of the University of California San Diego, La Jolla, and colleagues collected physical activity data on 1,032 children when they were 9 years old until they were age 15. Physical activity was measured by the children wearing an accelerometer, a monitor worn on a belt that records minute-by-minute movement counts. The children would wear this monitor for one week a year at ages 9,11,12 and 15. The study took place in 10 geographic locations from 2000-2006. Participants included boys (517 [50.1 percent]) and girls (515 [49.9 percent]); 76.6 percent white (n = 791); and 24.5 percent (n = 231) lived in low-income families.

The researchers found that both the average minutes of MVPA and the range of minutes spent in MVPA decreased as children moved into adolescence. At 9 years, children engaged in MVPA approximately 3 hours per day on both weekdays and weekends. By 15 years, adolescents were only engaging in MVPA for 49 minutes per weekday and 35 minutes per weekend day. At 9 and 11 years, almost all children met the guidelines (of 60 minutes of MVPA per day), but by 15 years, only 31 percent and 17 percent met guidelines on weekdays and weekends, respectively. Both weekday and weekend MVPA showed significant decreases in MVPA between 9 and 15 years, with decreases of 38 and 41 minutes per year, respectively.

The estimated age at which girls crossed below the recommended 60 minutes of MVPA per day was approximately 13.1 years for weekday activity compared with boys at 14.7 years, and for weekend activity, girls crossed below the recommended 60 minutes of MVPA at 12.6 years compared with boys at 13.4 years.

"More research is … needed to understand the reasons for such substantial decreases in youth activity. Further study and more precise descriptions of the immediate activity environment, such as whether youth are located in urban, suburban, or rural areas; availability of safe places to be active; and quality of school-based physical education may explain some of the individual and regional differences noted in this and other studies."

"This decrease augurs poorly for levels of physical activity in U.S. adults and potentially for health over the course of a lifetime. Consequently, there is a need for program and policy action as early as possible at the family, community, school, health care, and governmental levels to address the problem of decreasing physical activity with increasing age," the authors conclude.

Source: JAMA and Archives Journals

Explore further: Study highlights concern for homeless seniors

add to favorites email to friend print save as pdf

Related Stories

Yelp to pay US fine for child privacy violation

39 minutes ago

Online ratings operator Yelp agreed to pay $450,000 to settle US charges that it illegally collected data on children, in violation of privacy laws, officials said Wednesday.

Coral growth rate plummets in 30-year comparison

59 minutes ago

A team of researchers working on a Carnegie expedition in Australia's Great Barrier Reef has documented that coral growth rates have plummeted 40% since the mid-1970s. The scientists suggest that ocean acidification ...

Iberian pig genome remains unchanged after five centuries

1 hour ago

A team of Spanish researchers have obtained the first partial genome sequence of an ancient pig. Extracted from a sixteenth century pig found at the site of the Montsoriu Castle in Girona, the data obtained indicates that ...

Recommended for you

ER waiting times vary significantly, studies find

2 hours ago

(HealthDay)—When it comes to emergency room waiting times, patients seeking care at larger urban hospitals are likely to spend more time staring down the clock than those seen at smaller or more rural facilities, ...

Internists report considerable EMR-linked time loss

2 hours ago

(HealthDay)—Use of electronic medical record (EMR) systems is associated with considerable loss of free time per clinic day, according to a research letter published online Sept. 8 in JAMA Internal Medicine.

Kids eat better if their parents went to college

2 hours ago

Children of college-educated parents eat more vegetables and drink less sugar, according to a new study from the University of British Columbia. But it's still not enough, the study goes on to say, as all kids are falling ...

User comments : 0