The association between physical fitness and cardiovascular disease risk factors in children in a five-year follow-up study.

The relation between physical fitness and cardiovascular disease (CVD) risk factors was studied in 633 children selected from all fourth grades in 37 elementary schools in New York. They were participating in the control group of an intervention study to reduce CVD risk factors in children. Blood pressure, total and high-density lipoprotein (HDL) cholesterol and physical fitness were measured at baseline and at four subsequent examinations during five years of follow-up. Systolic blood pressure (SBP) at baseline was highest in children with poor physical fitness. The five-year change in physical fitness was inversely associated with the change in SBP, ie, children with the strongest decline in physical fitness showed the largest rise in SBP. HDL cholesterol at baseline was lowest in boys with poor physical fitness. The five-year change in physical fitness was positively related to the change in HDL cholesterol levels in boys; ie, boys with the largest decline in physical fitness had the largest decrease in HDL cholesterol level. These observations indicate that unfavourable long-term changes in physical condition in childhood may be related to unfavourable changes in blood pressure and serum lipids.