The interrelationships between habitual physical activity, physical fitness and cardiovascular disease risk factors in children
Description
The present study was conducted to determine if the well-documented adverse effects of a sedentary lifestyle on cardiovascular disease risk in adults could be detected in children. A sample of 71 fifth and sixth grade children in an elementary school in Metairie, Louisiana were screened for cardiovascular disease risk factors. A 3-day activity diary was used to assess (1) average daily energy expenditure, and the usual amount of time spent at (2) leisure sport activities and (3) active sport activities. Physical fitness levels were assigned according to performance on a 1-mile run/walk In girls, all three measures of physical activity were inversely associated with systolic blood pressure, diastolic blood pressure and percent body fat. In addition, quantity of time spent at leisure and total sport activities was negatively correlated with total and LDL cholesterol. Increased level of fitness was associated with lower diastolic blood pressure (p $<$ 0.05), total cholesterol, LDL, the LDL/HDL ratio, and estimated percent body fat (p $<$ 0.001). Among boys, only time spent at leisure sport activity demonstrated inverse associations with systolic blood pressure, total cholesterol, LDL, and the LDL/HDL ratio. Increased fitness levels were equated with lower systolic (p = 0.07) and diastolic blood pressure, the LDL/HDL ratio (p = 0.08), and percent body fat (p $<$ 0.0001). Positive correlations among fitness and HDL were observed for both sexes, but they were statistically significant only for the boys (p $<$ 0.01) The fitness-risk factor associations were always of greater magnitude than the physical activity-risk factor associations. These preliminary data suggest that the adverse effects of a sedentary lifestyle may already be evident in childhood