FRIDAY, Aug. 17, 2012 (MedPage Today) — Little couch potatoes have worse motor coordination than their active peers, which periodic bouts of exercise may not overcome, Portuguese researchers found.
Spending more than three-quarters of the day sedentary appeared to be a significant discriminating factor separating 9- to 10-year-olds with poor coordination from those with good coordination in a study led by Luís Lopes, of Minho University in Braga, Portugal.
Boys who spent more than 76 percent of their time sitting at school or at home in front of a TV or computer screen were 9.2 times less likely to have good coordination. Girls who spent more than 77 percent of their time sedentary were 5.1 times less likely to be coordinated.
Those links were independent of accelerometer-measured moderate-to-vigorous physical activity as well as waist-to-height ratio and other factors, the group reported online in the American Journal of Human Biology.
"Our findings suggested that physical activity levels per se may not overcome the deleterious influence of high levels of sedentary behavior on motor coordination," they wrote.
Gaining gross motor coordination is part of children's overall development and is thought to promote exercise and thus a healthier lifestyle, the researchers pointed out.
"Body composition, cardiorespiratory fitness, muscle strength and endurance, anaerobic capacity, power, and physical activity have all been negatively associated, to various degrees, with poor motor proficiency," they added.
However, the study couldn't determine causality in the link, which may work in both directions. More coordinated kids may feel more competent at sports and other activities and thus spend more time active; and kids who are more active better develop their motor coordination.
The study included 213 fourth graders at 13 public elementary schools in urban areas of a city in northern Portugal who wore accelerometers for five days.
When tested with a body coordination test evaluating tasks like walking on a balance beam to measure balance, speed, agility, and power, 46 percent of girls and 59 percent of boys had normal or good coordination.
Overall, 76 percent of kids' time was spent in sedentary behaviors, defined as a period with energy expenditure of less than 1.5 metabolic equivalents, akin to what is seen when sleeping, sitting, or watching television.
The accelerometer bypassed subjective recall bias and captured the entire daily pattern of activity, although it didn't allow the type of sedentary behavior to be distinguished, the researchers noted.
The group speculated "that providing children with alternatives to sedentary behavior, namely daily physical education classes, opportunities for sports participation in and outside school, and school recesses more conducive to activity, could have a positive impact on their motor coordination, which could in turn increase physical activity and decrease time spent in sedentary behaviors."
However, they acknowledged that further longitudinal and interventional studies would be needed to determine any real-world impact.
Additionally reviewed by Dorothy Caputo, MA