|Abstract or Summary
- The major purpose of this study was to determine if there were differences between well-trained pre- adolesents and untrained, but normally active counterparts in physical working capacity , body composition and blood lipids. The study hypotheses were that the trained subjects would have a lower mean body fat percentage, lower total cholesterol (TC), lower low-density-lipoprotein cholesterol (LDL-C), higher high-density-lipoprotein cholesterol (HDL-C) and higher mean physical working capacity at a beat rate of 150 bpm (PWC₁₅₀) than normally active children. Thirty-five school children, ranging in age from 8 to 11 years, volunteered as subjects for this study. The trained subjects were children who had trained for competitive swimming or running events for at least one year prior to the start of the study. The normally active group were children who had recently participated in the children's instructional sports program at Oregon State University. Subjects underwent a cycle ergometer test to measure PWC₁₅₀. Skinfold thickness measurements and hydrostatic weighing were conducted to estimate body composition, and fasting blood samples were obtained by venipuncture to determine TC, LDL-C, and HDL-C. The resulting data were statistically analyzed using an independent t -test to compare mean PWC₁₅₀, body fat percentage, body density, TC, LDL-C, and HDL-C between the two groups of subjects. To further analyze the relationship among the variables, a Spearman rank-order correlation coefficient was calculated. An alpha level of 0.05 was established for acceptance of statistical significance. The PWC₁₅₀ for the trained group was significantly higher than for the normally active group, whereas the body fat percentage for the trained group was significantly lower than for the normally active group. There were no significant differences between groups in any of the blood cholesterol concentrations. The Spearman correlation determined that there was a significant positive relationship between TC and LDL-C. This study confirms that programs of strenuous physical activity tend to enhance fitness levels in school age children. The implication is that school physical education classes should be strenuous in nature and meet at least three times weekly.