Among the dumbest things in the world are books and articles and how-to advice from people for whom the activity in question was second nature:  How to Stay Slim, by This Week's Supermodel.  Making It In Showbiz, by Leonardo DiCaprio.  How to Dunk a Basketball, by LeBron James.  Do these Pick-6-Genetic-Lottery Freaks really have any useful advice for the rest of us? 

So it doesn't make a lot of sense for me to dish out advice on keeping your kids active, even though I do get asked about it from time to time.  My daughter's no Serena, but she's loved to move practically from her first day out of the womb:  dancing, running, climbing.  When I picked her up from school today, she literally skipped the whole quarter-mile back to the car.  She has springs in her feet. 

I was talking to my friend Stephen yesterday (this guy again) who teaches martial arts to kids.  Offhand, he mentioned that he was having the kids do plyometric lateral-jumps over a one-foot diameter cylinder for one-minute interval repeats that day.

If that doesn't sound tough, try it sometime.   Then, if you even have the strength for a second round, try it with a two-foot cylinder, because that's closer to the size and shape of the thing these kids are hurdling relative to their size.

Trust me, it's no cakewalk.  

"Wow, Stephen," I said.  "Sounds like you're quite the taskmaster."

Hardly, he said.  "The kids love it.  They can't get enough of it."  

Sure, a kids' martial arts class is a self-selecting group:  they're going to be active anyway.  And maybe there's a larger than average percentage of kids whose parents thought "Maybe if little Clay burns off some energy in karate class...".  

And of course there will be exceptions:  some kids just never seem to take to physical activity.  Someday there will be a study made of such people and we'll discover that they're endorphin-desensitized or something. 

Still, I was initially surprised that these kids--all of them, it would seem--could not only handle such a tough workout but enjoy it, and indeed, thrive under that kind of challenge. 

But then I thought about my daughter's friends tearing around the playground at her school; her own rambunctiousness when she has playdates with friends.  Most kids are inclined to play hard.  It seems to be in their blood.  In most cases, lazy-child syndrome seems learned behavior.  

I wondered if the lazy-child syndrome weren't actually--at least in part--lazy-parent syndrome in disguise.  Given the chance, these kids were enthusiastic about exercising much, much harder than most adults ever do.  Maybe some kids just aren't given the chance, or just don't get the chance often enough.

I realize this is partly a function of practical constraints in peoples' lives.  Not everyone has the disposable income or free time to take their kids to classes so that someone else can make them sweat.  But, as I've written before, it is possible to combine two activities that almost everyone agrees we can't get enough of by exercising with your kids. 

And of course there's no substitute for setting a good example.  I did one of my insane backyard obstacle-course workouts at home the other day--the ones that are equal measure hard and absurdly fun--and my daughter, who'd been playing inside, took one look at me hanging from our tree, shuttle running between shrubs, crab-walking around obstacles, jumping over chairs, and farmer's-walking with five-gallon jugs in my hands, that she had to dive right in herself. 

I don't imagine she would have felt similarly inclined if I'd been running on a treadmill and looking like I was on a death-march to the Seventh Circle of Fitness Hell.