More than 3,000 adolescents (age 12-19 years) underwent an 8 minute treadmill test that increased their heart rates and consumption of oxygen. After this cardiovascular 'stress test', they were classified as either "fit" or "unfit", based on national normal values.

What the study found
Low fitness was identified in 1/3 of adolescents (= 7.5 million US adolescents). The prevalence was similar in females and males. Non-Hispanic blacks and Mexican Americans were less fit than non-Hispanic whites. Poor fitness was associated with higher blood pressures, with being fatter, with higher cholesterol and lower "good fat" (HDL) levels.

What this study suggests
From an early age, many American children are out of shape, placing them at greater risk for heart disease, diabetes, even some types of cancer as adults.

Everyone knows about the epidemic of obesity in children - 1 out 6 American children is seriously overweight. Now we find that fully 1 out of 3 adolescents can't pass a simple treadmill test of cardiovascular fitness!

Obesity is no mystery: too many calories in and not enough exercise. There are many benefits of a low animal fat diet for your family, but that is only half the story.

Other studies have shown that, even by age 3 years, children are not as active as they used to be. You can guess why: TVs, computers, escalators, cars, and parents/adults who may not be the best role models --> CPITs (couch potatoes in training).

Make physical fitness a family value. Be sure there are opportunities to exercise every day, take walks or ride bikes together, climb the stairs instead of the escalator, sign your kids up for their sport of choice, talk to them about the benefits of exercise (health, fun, feeling good, competence at sports).

It's not that often we can see trouble so clearly down the road and actually have effective ways to prevent it. If your family serves high calorie foods with lots of animal fat and have kids who don't get much exercise... well, no one really doesn't need to badger you: you know what you need to do. Now is as good a time as any to get started.