Lack of exercise linked to higher heart disease risk in healthy children as young as 9

Sample 200 children in Sweden and Denmark, monitored for four days using accelerometer and assessed for cardiac risk factors including blood pressure, BMI etc.  Moderate to vigorous physical activity accounted for eight per cent of the variance in the accumulated cardiac risk scores

http://medicalxpress.com/news/2011-05-lack-linked-higher-heart-disease.html