Physical Activity, Physical Fitness, and Coronary Heart Disease Risk Factors in Youth: The Québec Family Study,

Objective. The relationships between physical activity, fitness, and CHD risk factors were investigated in 342 males and 268 females 9–18 years of age. Methods. Daily energy expenditure, moderate to vigorous physical activity, inactivity, and television viewing time were estimated. Indicators of physical fitness included submaximal work capacity, quadriceps muscle strength, sit-ups, and the sum of six skinfolds. Risk factors included mean arterial blood pressure and fasting blood levels of triglycerides, LDL-cholesterol, HDL-cholesterol, and glucose. Results. Canonical correlations between activity and risk factor profiles range from 0.22 to 0.45, while those between fitness and risk factor profiles range from 0.34 to 0.55, indicating that 5 to 20% and 11 to 30% of the variance in the risk profile is explained by activity and fitness, respectively. Conclusion. The results suggest that both physical fitness and level of habitual physical activity are strongly associated with CHD risk factors in this sample of youth.