Preschoolers are bundles of seemingly boundless energy.

But you may be surprised to learn that many of them don’t get enough exercise during a normal day. A recently published study by Seattle researchers looked at 10 licensed day-care centers, each for a 50-day period.

The scientists tracked how 3-to-5-year-old kids spent their time, and also had them wear sensors to gauge their movement.

The results were less than stellar. The scientists found the kids got an average of just 48 minutes of active play opportunities per day. The study authors juxtaposed this against the two hours recommended for this age group by the National Association for Sport and Physical Education.

And data from the sensors the preschoolers wore showed they averaged just 14 percent of their child-care time in moderate or vigorous physical activity. Most of the time they were sedentary. During the remaining time, they engaged in light activity.

The study results showed that kids tended to be most active during outdoor playtime and during “free” play time, rather than indoor play or activities led by child-care providers. No surprises there.

Considering that 18 percent of children are obese, these findings from child-care centers are certainly troubling.

To help ensure plenty of activity, parents should select child-care centers that emphasize exercise. Because outdoor time is key, one with space for outside play is ideal.

The researchers also pointed to past studies showing play equipment that’s movable … such as balls and riding toys … encourages more activity.

These seemingly small considerations may help your little one get plenty of exercise at child care … and hopefully tire him out for a night of restful sleep.