Cardiorespiratory Fitness, Physical Activity Patterns and Coronary Risk Factors in Preadolescent Boys

Abstract

The relationships between cardiorespiratory fitness, daily physical activity, and selected coronary artery disease (CAD) risk factors were evaluated in a sample of 91 preadolescent boys. Cardiorespiratory fitness was assessed (VO2max). Physical activity level was assessed using daytime heart rate telemetry. CAD risk factors included total cholesterol, fasting triglycerides, HDL-cholesterol, LDL-cholesterol, fasting blood glucose, systolic and diastolic blood pressures, and body fat content. The mean value of VO2max exhibited significant negative relationship with body fat percent (r = -0.55). Controlling the effects of age, body mass index and body fat percent resulted in a significant inverse relationship between physical activity and systolic (r = -0.29) and diastolic (r = -0.28) blood pressures. Analysis of data by quartiles revealed significant differences only in body fat percent across fitness categories, while no significant differences were detected in the other CAD risk factors. However, higher HDL-cholesterol and lower triglycerides levels were observed in those boys with higher levels of physical activity. It was concluded that except with body fatness, cardiorespiratory fitness is not strongly associated with lower CAD risk factors, while physical activity level was significantly associated with lower blood pressure level but not with the other CAD risk factors.

Blood lipids of young distance runners: distribution and inter-relationships among training volume, peak oxygen consumption, and body fatness

“…The positive association between _ V O 2peak and HDL-C concentration was consistent with previous studies of young people (Al-Hazzaa et al 1994;Armstrong et al 1991;Macek et al 1989;Sallis et al 1988;Suter and Hawes 1993;Tell and Vellar 1988;Valimaki et al 1980). The association between _ V O 2peak and HDL-C concentration (r=0.41) was similar to previous studies of welltrained athletes as well.…”

The physical activity, fitness and health of children

“…Alpert and Wilmore (1994) concluded that aerobic training had only a weak relationship with blood pressure within the normal range, but that such training consistently reduced both systolic and diastolic blood pressure in hypertensive adolescents. Riddoch (1998) reviewed more recent studies and reported that, for lipids and lipoproteins, six studies (Al-Hazzaa et al, 1994;de Visser et al, 1994;Dwyer and Gibbons, 1994;Harrell et al, 1996;Rowland et al, 1996;Webber et al, 1996) showed no association with measures of activity, whereas another six (Suter and Hawes, 1993;Bistritzer et al, 1995;Craig et al, 1996;Gutin et al, 1996;Twisk et al, 1996;Boreham et al, 1997) showed a limited association. For blood pressure, one study (de Visser et al, 1994) reported no association, while seven (Jenner et al, 1992;Al-Hazzaa et al, 1994;Anderson, 1994;Dwyer and Gibbons, 1994;Harrell et al, 1996;Webber et al, 1996;Boreham et al, 1997) reported a bene® cial association.…”

Aerobic fitness, fatness and the metabolic syndrome in children and adolescents

“…In other words, the obese are the unfit, therefore the above findings represent a common phenomena. This is a good point, but when one examines the association between aerobic fitness and fatness the correlation generally ranges from 0.40 to 0.60 (26)(27)(28)(29). Using a correlation of 0.50, this means that the shared variance is only 25%.…”