Short bouts of activity lower blood sugar.

• Position: Children's Exercise - Brief article

Brief intervals of exercise during otherwise sedentary periods may offset the lack of more-sustained exercise and could protect children against diabetes, cardiovascular disease, and cancer, according to a study by researchers at the National Institutes of Health, Bethesda, Md. Children who interrupt periods of sitting with three minutes of moderate-intensity walking every halfhour have lower levels of blood glucose and insulin, compared to periods when they remained seated for three hours. Moreover, on the days they walk, the children did not eat any more at lunch than on the days they remain sedentary.

"We know that 30 minutes or more of moderate physical activity benefits children's health," relates Jack A. Yanovski, chief of the National Institute of Child Health and Human Development's Section on Growth and Obesity. "It can be difficult to fit longer stretches of physical activity into the day. Our study indicates that even small activity breaks could have a substantial impact on...