Our kids are out of shape, watch too much TV and often feel anxious about learning.

School is in full swing. Homework, backpacks and studying have replaced "chasing fireflies" and "poolside" in our vocabularies. Lots of students are back to a steady diet of rigidly structured, highly plugged-in sedentary activities. If we're honest, some of us began longing for the school year grind back in July-when our kids' laid back summer felt anything but laid back to us. If we're brutally honest, a lot of us over-schedule out of anxiety about beefing up our children's competitiveness and resumes for college.

But science reminds us we need to chill. While academics and organized sports are important, kids need goof-off time. To stay healthy, children of all ages need plenty of unstructured play.

Hard-wired for play
Dr. Stuart Brown, clinical researcher and author of Play: How it Shapes the Brain, Opens the Imagination, and Invigorates the Soul (Avery, 2009) studied the play behavior of animals and more than 6,000 people from all walks of life (serial killers to Nobel Prize winners). His research concludes that play time is critical to the emotional, social and cognitive health of our children.

Everyone understands play is pleasurable and a good distraction from stress, but science also teaches us that play "is a profound biological process" crucial to our survival. In rats, play reduces impulsivity, which is similar to ADHD in humans. We are simply hard-wired to play. Unfortunately, recess and P.E. are disappearing from the school day at a time kids need unstructured free-play more than ever.

Brown says making play a part of our daily lives is critical to feeling fulfilled as happy, successful human beings. What constitutes play? The retired psychiatrist says play is much more than games and sports. Play involves books, music, art, jokes, movies, drama and daydreaming.

12 reasons to push play
Happier kids. Sometimes we trivialize play or fail to see its usefulness. But it's more than fun. In addition to improving emotional health, it serves a biological purpose. Emotional control and resilience. When social mammals such as rats and monkeys are deprived of rough-and-tumble play, they enter adulthood emotionally fragile. Play helps them distinguish friend from foe, handle stress better and form better skills to mate properly. Social competence is enhanced. Play teaches people to master and adapt to changing circumstances. Even "dealing with or avoiding being excluded" from games like tag or dodge ball are helpful social skills to learn. Physical activity may lessen the symptoms of mild ADHD. Dr. Lara Honos-Webb, author of The Gift of ADHD, says of the disorder "it is important to remember that nature is medicine and activity is medicine." She suggests that parents of children with ADHD make time for them to run around outside before school and be sure that recess is never taken away as a punishment for poor behavior. May prevent a smoldering depression. Play is not just a trivial escape. It provides a vehicle for learning to problem solve, and as Dr. Brown writes, "reshapes our rigid views of the world." Burns calories. Trends for childhood obesity are staggering. According to the CDC, the prevalence of childhood obesity for 6-11 year-olds has increased from 6.5 percent (1976-80) to 17 percent (2003-2006). Obese kids have increased risk for cardiovascular disease, asthma, sleep apnea and type 2 diabetes. We don't want kids to grow up to be rigid, humorless adults. After analyzing thousands of "play histories," Brown stresses that play deficiencies can lead to closed-mindedness, inflexibility and unhappiness. Lifelong play is part of the antidote. Rough and tumble play is developmentally critical. We knew it was helpful to development, but Dr. Brown's research revealed that for young homicidal males and drunk drivers, rough-and-tumble play was missing from their childhoods. Stronger academic performance. This may be especially relevant for boys. Anthony Pellegrini, an educational psychology professor at the University of Minnesota and author of Recess, discovered that successful peer interaction at recess was an excellent predictor of success on standardized tests. When boys established competence on the playground, they also did better in the classroom and paid attention better. Play keeps curiosity and wonder alive. Kids today spend 50 percent less time outside than they did just 20 years ago. The lure of animation, xBox, and online networking is so tempting and culturally reinforced that the beauty of nature and fresh air right outside our doors is often overlooked. Successful people play A LOT. Playfulness sparks creativity and innovation. Analysis of the play histories of successful adults reveals "Highly successful people have a rich play life." Play is honorable. Play is not just a mindless activity-it's active learning. As Brown says, "From an evolutionary perspective, the smarter the animal, the more they play it gets us in touch with our core selves and the joy of life." Michele Ranard is passionate about helping parents and children live richer lives. She is a professional counselor, tutor and freelancer who loves to laugh. You can read her blog at micheleranard.blogspot.com.