We all fret about the obesity epidemic among children as well as adults today. But few of us worry about our children when they are in the normal weight range and seem totally healthy. The problem is that we should be very worried if our thin kids tend to be couch potatoes.
A recent study at Skane University Hospital in Malmo, Sweden, showed that pre-adolescent children have a higher risk of cardiovascular disease if they are not physically active.1 There were 123 boys and 100 girls participating in the research. The average age of these volunteers was 9.8 years old.
The subjects wore an elastic belt around their waists with an accelerometer attached to measure the speed, distance, and physical force of any movements. They spent a minimum of eight hours a day wearing the belt for four consecutive days. The children also were examined to determine their blood pressure, amount of body fat, resting heart rate, and overall fitness.
Given the number of studies that have shown how dangerous inactivity is to adults of all ages, it is not surprising that this research found it is similarly risky for young children. Although the average body mass indexes (BMIs) were in the healthy range for the subjects -- at 17.5 for the girls and 17.4 for the boys -- that did not tell the entire story. These kids may have looked lean and healthy, but the less active among them were already on a path toward cardiovascular disease.
The composite risk factors for developing heart disease were much higher in those children who were not participating in moderate to vigorous types of physical activity and getting their heart rates up. In general, the boy participants spent more time active than the girls, and their exercise was typically more rigorous. Despite their normal BMIs, the boys had a lower percentage of body fat than the girls -- 16.2 percent as compared to 22.6 percent) -- and lower total body fat mass -- 6.3 kg for the boys and 8.3 kg for the girls. These are cardiovascular risk factors that will only get worse over time as the children age and become even more sedentary unless something is done to break the cycle.
High blood pressure, a major risk factor for cardiovascular disease, has been linked in studies of preschool and elementary school age children to watching too much television -- just one sedentary thing among many that kids are spending time doing instead of playing sports or tag or riding their bikes. One study at Iowa State University in Ames in 2009 included 111 children aged three to eight.2 All the kids wore devices that measured their overall activity levels. In addition, their parents reported how much time the youngsters spent watching TV and doing other low-level activities. The average amount of sedentary time was five hours daily, with 1.5 hours spent in front of a screen.
Overall, those children who spent the least amount of time in front of a screen had far lower blood pressure than those who spent the most time. And according to the American Heart Association, only one percent of young children had hypertension 20 years ago, but by 2002 that percentage had increased fivefold. Among inner city and minority kids, up to 25 percent have the condition, and many more kids are pre-hypertensive.
Since not many five-year-olds are going to walk away from the television any time soon, it's up to us as parents to take charge. Most young children are happy to get moving if we take the time to find the activities they enjoy. It's also essential to be a role model in this case -- not only will they love having mom and dad running right alongside them and spending time together, but you will be setting both yourself and your children up for a happier, healthier life down the road.
And if you find that you just can't get your children away from the TV, then turn your TV into your ally. As we discussed last year, there's a whole new world of video games now available that require a high degree of total body physical interaction. That's right; you can use your TV to elminate hypertension.
1 Tanha, Tina; Wollmer, Per; Thorsson, Ola; Karlsson, Magnus K.; Linden, Christian; Andersen, Lars B.; Dencker, Magnus. "Lack of Physical Activity in Young Children is Related to Higher Composite Risk Factor Score for Cardiovascular Disease." Acta Paediatrica. 24 March 2011. John Wiley & Sons, Inc. 17 May 2011. <http://onlinelibrary.wiley.com/doi/10.1111/j.1651-2227.2011.02226.x/abstract>.
2 Martinez-Gomez, David; Tucker, Jared; Heelan, Kate A.; Welk, Gregory, J.; Eisenmann, Joey C. "Associations Between Sedentary Behavior and Blood Pressure in Young Children." Archives of Pediatrics & Adolescent Medicine. August 2009. American Medical Association. 18 May 2011. <http://archpedi.ama-assn.org/cgi/content/abstract/163/8/724>.