Activity levels of U.S. teens 'alarmingly low' finds new research

New research has found that physical activity among children and teens is even lower than previously thought. © Cat London/istockphoto.com

New U.S. research has found that physical activity among children and teens is even lower than previously thought, with activity levels of 19-year-olds comparable to that of 60-year-olds.

Carried out by a team from the Johns Hopkins Bloomberg School of Public Health, the study used data from the National Health and Nutrition Examination Survey involving 12,529 participants.

The researchers divided participants into five different age groups: children (ages six to 11); adolescents (ages 12 to 19); young adults (ages 20 to 29); adults at midlife (ages 31 to 59); and older adults (age 60 through age 84).

To assess activity levels all subjects wore tracking devices for a seven-day period, taking them off only for bathing and bedtime.

The devices measured how much time participants spent been sedentary or engaging in light or moderate-to-vigorous physical activity.

The team found that the recommended activity guidelines set by the World Health Organization (WHO) are not being met, with the study's senior author Vadim Zipunnikov describing the activity levels of older teens in particular as "alarmingly low."

Although WHO advises at least 60 minutes of moderate-to-vigorous physical activity a day for children ages five to 17 years, the research found that more than 25 per cent of boys and 50 per cent of girls ages six to 11 failed to meet this recommendation.

And the figures only increased as the children got older, with more than 50 per cent of male and 75 per cent of female adolescents ages 12 to 19 failing to meet the activity guidelines.

The team also found that levels of physical activity only increased at one point in life, between age 20 and 30, before stabilizing during midlife, classed as ages 31-59.

Another finding from the study is that males generally had higher activity levels than females, particularly when looking at their levels of high-intensity activity. However after midlife, these levels also dropped off more sharply when compared to that of females. Males over 60 years were also more sedentary and engaged in lower levels of light-intensity activity levels than females.

Although WHO bases its recommendations on moderate-to-vigorous activity, the researchers say that there is growing agreement that even just increasing low-intensity levels of physical activity, and decreasing sedentary time, still has benefits, with the findings coming amid heightened concern about the growing obesity epidemic, particularly among children and teens.

The findings can be found published online in the journal Preventive Medicine.