FIVE THINGS ABOUT EXERCISE STUDY

The adolescent years should be among the most active periods in a person’s lifetime. It turns out they are not. In an eye- opening study involving 12,529 Americans aged six to 85, researchers mapped how physical activity changes over a lifetime. The participants wore accelerometers, devices that measure movement, for seven consecutive days. Here are five findings.

1 YOUTH MOVEMENT

Physical activity appears to be at its highest at age six. Vijay Varma, a National Institute of Aging researcher and lead author of the study, said there was a sharper- than- expected decline in physical activity during childhood. By age 19, the average American is as sedentary as a 60-year- old.

2 SCHOOL BLAMED

Varma theorized that the modern school day, which requires sitting for large amounts of time and where recess is often compressed into 20-30 minutes a day, may be partly to blame.

3 SCREEN TIME

Another reason for the sedentary day is likely to be screen time. Studies about how long we spend parked in front of our TVs, laptops, tablets and phones tend to become outdated quickly due to the constant rollout of new technology, but the numbers have been consistently high — as much as 7 to 9 hours per day.

4 FALLING SHORT

Most children are not getting the minimum amount of activity — at least 60 minutes of a moderate- to- vigorous workout — recommended by the World Health Organization. Among 6- to 11- yearolds, 25 per cent of boys and 50 per cent of girls were not meeting the target. For adolescents ages 12 to 19, the situation was even more dire, with 50 per cent of males and 75 per cent of females falling short, the study found.

5 WEAR AND TEAR

As expected, physical activity starts to decline at around age 35 and that trend continues through mid- life and beyond. That’s consistent with previous studies and attributed to the wear and tear on our bodies as we age.