Dear Mr. Dad: There’s a lot of talk about childhood obesity. How do you think that’s going to affect the next generation of athletes? Will we be able to compete on a world stage in the future if today’s kids are so out of shape?

A: When I was in the fourth grade, I was one of the fastest kids in my school. I remember coming home one afternoon beaming after having won some kind of sprint and telling my parents—and my grandparents, who were over for dinner—all about it. My grandfather, who was 72 at the time, challenged me to a race. So we went outside and he proceeded to kick my 9-year old butt.

In my defense, grandpa was a freak of nature. He worked at backbreaking jobs most of his life and died at 103—after decades of stuffing his face on mac and cheese and fried chicken at all-you-can-eat buffets—and he did 100 pushups every day almost to the end. But I was reminded of that somewhat humiliating day when I read the results of a new study of childhood fitness that found that “kids these days”—as we love to call them—are much slower runners than their parents.

According to Grant Tomkinson, the study’s lead author and a senior lecturer in the University of South Australia’s School of Health Sciences, worldwide, children today are 15 percent less aerobically fit than we were at their age (in the U.S., the cross-generational fitness disparity is more than 18%). In more understandable terms, today’s kids take 90 seconds more to run a mile than kids the same age did just 30-40 years ago.

Tomkinson and his colleagues figured all this out by analyzing dozens of studies done since 1964, covering more than 25 million kids 9-17 in 28 countries. The tests covered anywhere from one half a mile to two miles and lasted between 5 and 15 minute. They measured either how long it took the kids to run a specific distance or how far they could run in a specific amount of time.

Out-of-shape kids tend to grow up to be out-of-shape adults. We’ve already seen skyrocketing increases in diabetes, heart disease, obesity, and osteoarthritis, and it looks like things are going to get worse.
I find it especially ironic, though, that at the same time children’s fitness levels has been slipping, we’ve experienced a huge increase in the number of kids getting involved in sports. So why are kids so slow? A few thoughts:

  • Organized, highly structured sports may build individual skills but they don’t encourage endurance.
  • Schools across the country are getting rid of Physical Education programs. I’ve seen estimates that only 4% elementary schools, 8% of middle schools, and 2% of high schools have P.E. every day.
  • Parents are so worried (usually unnecessarily) about their kids’ safety that they don’t let them walk or bike to school.
  • Electronic devices take up a lot of the free time that kids used to spend outside.
  • The amount of unstructured outside playtime kids have has plummeted.
  • Kids are fatter today than ever. Fat kids are going to be slow kids.
  • Parents don’t enforce the very sensible recommendation made by pediatricians and fitness experts that kids get 60 minutes of physical activity per day—physical activity that makes them sweat.

Back to your question: I don’t think our obesity problem will affect our country’s performance in the Olympics and other international competition. Elite athletes, like my grandfather, are freaks of nature—they’re simply not like the rest of us—and they’ll always exist. For regular folks like you and me, the solution is pretty simple. Take the kids out and make them exercise—with you, of course. It doesn’t really matter what it is, as long as it’s strenuous. Personally, I’ve been doing the Insanity DVD workouts for the past few months and I’ve corralled my 10-year old into doing them with me at least three days per week.