Alec Appelbaum writes about urban design and policy for the New York Times and others, focusing on ways cities can become healthier. He is a parent at PS 126 in Manhattan and enjoys exercising on his own and with his family. In "Fitness Focus," he'll be blogging about how to get physical education back in shape in city schools.

As parents, we all do things we never expected to do. For instance, I do daily stretches and run around with my pre-K daughter before breakfast, because otherwise she won't get enough activity during the day. (And yes, it's lots of fun.) I started that practice the same reason I'm starting the Fitness Focus blog:  because physical education is severely limited at most schools, and I see ways to rectify that.   

Statistics about kids' health can turn your stomach. Karen Lee, who manages the health effects of buildings for the New York City Department of Health and Mental Hygiene, told an audience of design professionals last week: "Over 40 percent of our elementary school children are overweight or obese, and this situation is actually worse than in the rest of the country."

Let's move our feet rather than wringing our hands. The Department of Education is rethinking how physical education fits into the school day, but the need for change is massive.

When you were a student, weren't you more prepared to sit through a class in  geometry or Shakespeare after you worked off some energy? Scholarship bears  this out. Action for Healthy Kids,an alliance of national medical groups, reports  "a strong correlation between aerobic fitness and academic performance as measured by grades in core subjects and standardized test scores." And this relationship intensifies with practice: "Several large-scale studies found improvements in  academic performance with increased time spent in physical education."<!--more-->

Conversely,  a gym-free day denies kids the chance to develop memory skills (which sports develop) and social skills (which sports reinforce). This is especially so in disadvantaged neighborhoods, where poor air quality and fears of truck traffic can lead parents to keep kids indoors after school.

Lori Rose Benson, head of fitness and health education at the DOE, says the department is training phys-ed teachers, and encouraging classroom teachers, to incorporate aerobic activity into daily lessons. But she lacks adequate money and power.  City schools grapple with limited funds and limited space- some new schools in old buildings have no gyms, and others are severely overcrowded.

Benson is moving on several fronts. She's put middle-schoolers through a fitness test that statisticians are now correlating to academic test scores (with evidence of a positive correlation to be released this year). She's found money for fitness teachers' professional development and trained 1200 teachers to stitch active sessions into classroom modules. She's promoting a national curriculum called Physical Bestand a middle-school curriculum hat emphasize helping kids find athletics they enjoy.

But without more phys ed teachers and a clearer mandate from the DOE, principals can still scuttle phys ed budgets.

Diane Hamilton, assistant principal for fitness at Lehman High School  in the Bronx told me: "I've been here since 1981. I know the majority of phys-ed teachers and they're jammed with 50 kids, and sometimes 100. By the time all the kids do a mild stretch, I can count on one hand the times they'll touch a volleyball."

Yet Hamilton and a few others have busted the old model by forming inventive partnerships. At Hamilton's school, students get $35/year  memberships to nearby Dolphin Fitness clubs and can use a nearby pool. At my daughter's school, PS/MS 126 in Manhattan, grants filled the closet behind the "gymnatorium" with exercise machines - and put a climbing wall on the stage.

Is this adequate to address the obesity epidemic? Not by a long shot, Hamilton told me. "Kids today don't learn to hop, skip and jump."

You start with a single step- so where to?  In upcoming weeks, I'll explore new partnerships  with nonprofits, creative use of cramped buildings, and good phys-ed teachers' welcome emphasis on fun and collaboration. Please tell us what's working (and not working) in your school.