Interrupting sitting with walking breaks improves children's blood sugar

A sedentary lifestyle can put children at risk of developing pediatric obesity and metabolic health problems such as diabetes. Nearly 17 percent of children and teens nationwide are obese, according to the Society's Endocrine Facts and Figures report. A 2013 study estimated that elevated body-mass index in childhood was linked to $14.1 billion in prescription drug costs and emergency room and outpatient visits annually according to the report.

"Interrupting a long period of sitting with a few minutes of moderate activity can have short-term benefits on a child's metabolism," said the study's senior author, Jack A. Yanovski, MD, PhD, of the NIH's Eunice Kennedy Shriver National Institute of Child Health and Human Development (NICHD). "While we know getting 30 minutes or more of moderate intensity exercise each day improves children's health and metabolism, small behavioral changes like taking short walking breaks can also yield some benefits."

The randomized crossover trial examined sedentary behavior and metabolism in 28 normal-weight children who were between 7 and 11 years old. On two different days, the children either sat continuously for three hours or took 3-minute breaks to walk on a treadmill every half hour during that period. The study participants had their blood sugar and insulin levels tested before and after the experiment. The children drank a sugary soda-like drink prior to sitting so that researchers could measure how their bodies processed the sugar.

When children took breaks to walk, their blood sugar and insulin levels were lower than when they sat continuously. The findings indicate the children's bodies were better able to maintain blood sugar levels when their sitting was interrupted.

"Sustained sedentary behavior after a meal diminishes the muscles' ability to help clear sugar from the bloodstream," said first author, Britni Belcher, PhD, of the National Cancer Institute. "That forces the body to produce more insulin, which may increase the risk for beta cell dysfunction that can lead to the onset of Type 2 diabetes. Our findings suggest even short activity breaks can help overcome these negative effects, at least in the short term."

Additional exercise did not appear to affect the participants' appetites. The researchers provided the children with a buffet meal after the blood sugar testing was completed. The children selected similar amounts and types of foods, regardless of whether they had engaged in continuous or interrupted sitting that day.