Whether young or old, Americans continue to live sedentary lifestyles, as evidenced by a new study.
Researchers from the Johns Hopkins Bloomberg School of Public Health found that the average American teenager is no more as physically active than the average 60-year-old. This suggests that levels of exercise or physical activity among children and teens were lower than previously thought.
Led by Vadim Zipunnikov, the research team examined records from more than 12,500 respondents of different ages who wore physical activity tracking devices for a week straight as part of health surveys performed in 2003 to 2006.
Although the World Health Organization recommends about 60 minutes of daily moderate to vigorous physical activity for children and teens, Zipunnikov and his colleagues found that many respondents from this age group do not reach the WHO's guideline and have low levels of physical activity.
For instance, more than 50 percent of girls and 25 percent of boys aged 6 to 11 do not get 60 minutes of physical activity. The same goes for more than 75 percent of females and 50 percent of males who were 12 to 19 years old, researchers said.
The only improvements in levels of physical activity among young adults occurred during their 20s. What's more, levels of physical activity fell sharply during midlife and adulthood.
"Activity levels at the end of adolescence were alarmingly low," said Zipunnikov. "By age 19, they were comparable to 60-year-olds."
In all age groups, male respondents tended to be more physically active than female respondents. After midlife, however, the activity levels of men decreased sharply compared to that of women.
Among those who were 60 years old and older, men were more physically inactive and had lower levels of light-intensity activity than women.
Increasing Physical Activity
Furthermore, researchers found different times throughout the day when physical activity was highest and lowest among the respondents. For school children, the main window for physical activity was in the afternoon, during 2 p.m. to 6 p.m.
Zipunnikov and his team believe such information could help boost exercise and physical activity among children and teens by targeting times with the least activity. With that in mind, they wonder how daily schedules in schools can be modified to become more suitable in increasing exercise and physical activity among children.
Lastly, Zipunnikov and his colleagues said that although WHO recommends moderate to vigorous physical activity for children and teens, low-intensity physical activity should also be encouraged.
Details of the study are published in the journal Preventive Medicine.