By Dr. Brian McDonough, Medical Editor

PHILADELPHIA (CBS) - You don’t need a scientific study to understand this because it seems obvious but many parents forget how important it is.

Time spent with your children in parent-supervised playtime can be extremely valuable. But, according to a report in the Archives of Pediatrics and Adolescent Medicine about half of the preschoolers in a nationally representative sample did not have at least one parent-supervised outdoor playtime per day.

The study results indicate that 51 percent of children were reported to go outside to walk or play at least once a day with either parent. Obviously independent play in a safe environment is great but parents need to interact with their kids on a regular basis. It makes a big difference.