I admit it: this time of year, my children don't get enough exercise. It's hard to drag them outside to play when we live in a northern, urban environment with no yard, and the playgrounds are sad and frozen.

There are only so many after school activities one can sign up for. The school does what it can, but its indoor facilities have limits, and if the temperature dips below freezing the teachers can'trisk frostbitten children. On not-so-bitterly cold days, the kids adjourn to the playground for recess, and I see them running around giddily, as though gulping fresh air for the first time.

When the weather's too harsh to venture outside, the students sometimes watch a movie in the auditorium -- to their intense delight. I don't mind the occasional movie, but it's no substitute for the kids moving their bodies.<!--more-->

Last week, the occupational therapist at Night Owl's school told us she needed more exercise -- whether it be physical therapy or swimming lessons at the "Y". In the back of my mind I had known this. While not obese --she's underweight -- she needs to build up her core strength and stamina (not in hopes of becoming a junior Olympian, but simply to keep up with the class and sit straight during circle time). I'm sure more exercise will help her overall focus, too.

Apparently ours is not an isolated condition -- far from it. It's part of a larger dysfunction of lifestyle in this country: there's less physical activity and more time spent in front of TV and other media. In our house, where we don't have cable or Wii, the problem is there, nonetheless: art projects and stories, while constructive, are still not exercise. As a child, I spent far more time playing outside than my daughters do.

Michelle Obama cited this national exercise shortage, and the overall epidemic of childhood obesity and poor health, this week with the launch of her "Let's Move" initiative. She called attention to alarming statistics, such as a more than triple leap in childhood obesity since 1980 and an upswing of related diseases such as type II diabetes, heart disease, asthma, poor self-esteem, and a shorter life expectancy. She called for improved nutritional standards as well as greater access to physical education programs.

In New York City, 1 in 5 kindergartners is obese. Among those who are not, what might be some of the hidden costs of too little physical activity? I know I have much room for improvement as a parent and need to bundle my kids up and get them outside more. I would also love to see more time built into the school day for movement, even if it cuts into lesson time.

How does your school's physical education program measure up? How do you get your kids moving during the winter?