Williford H N, Smith J F, Mansfield E R, Conerly M D, Bishop P A
Med Sci Sports Exerc. 1986 Apr;18(2):216-24.
This study investigates the utility of two equations for predicting minimum wrestling weight and three equations for predicting body density for the population of high school wrestlers. A sample of 54 wrestlers was assessed for body density by underwater weighing, residual volume by helium dilution, and selected anthropometric measures. The differences between observed and predicted responses were analyzed for the five models. Four statistical tests were used to validate the equations, including tests for the mean of differences, proportion of positive differences, equality of standard errors from regression, and equivalence of regression coefficients between original and second sample data. The Michael and Katch equation and two Forsyth and Sinning equations (FS1 and FS21) for body density did not predict as well as expected. The Michael and Katch equation tends to overpredict body density while FS1 underpredicts. The FS2 equation, consisting of a constant adjustment to FS1, predicts well near the mean but not at the ends of the sample range. The two Tcheng and Tipton equations produce estimates which slightly but consistently overpredict minimum wrestling weight, the long form equation by 2.5 pounds and the short form by 3.8 pounds. As a result the proportion of positive differences is less than would be expected. But based on the tests for the standard errors and regression coefficients, the evidence does not uniformly reject these two equations.
本研究调查了两个预测最低摔跤体重的方程以及三个预测高中摔跤运动员群体身体密度的方程的效用。对54名摔跤运动员的样本进行了水下称重以评估身体密度、用氦稀释法测量残气量，并测量了选定的人体测量指标。对这五个模型分析了观察到的和预测的反应之间的差异。使用了四种统计检验来验证这些方程，包括差异均值检验、正差异比例检验、回归标准误差相等性检验以及原始样本数据和第二个样本数据之间回归系数的等效性检验。用于身体密度预测的迈克尔和卡奇方程以及两个福赛思和辛宁方程（FS1和FS21）的预测效果不如预期。迈克尔和卡奇方程往往高估身体密度，而FS1则低估。由对FS1进行常数调整组成的FS2方程在均值附近预测良好，但在样本范围两端则不然。两个程和蒂普顿方程得出的估计值略微但持续高估最低摔跤体重，长形式方程高估2.5磅，短形式方程高估3.8磅。因此，正差异的比例低于预期。但基于标准误差和回归系数的检验，证据并未一致拒绝这两个方程。
