Statistical methods for studying the relationship between maximum aerobic power and body weight. Comparison between Twa and Oto of the lake Tumba area (Zaire)

Abstract

In neither 84 Twa Pygmoids of the Zairian equatorial forest, nor 60 Oto, their taller suzerains, are conditions fulfilled that allow for the (VO 2 max: body weight) ratio to express validly VO 2 max independent of body-mass. Neither population shows a significant departure from normality in the distribution of the two variables or from the rectilinearity of their relationship. The major axes of their bivariate distributions lead to an unbiased comparison of the two populations. The observed isometry contradicts some theoretical views concerning the relative dimensionality of the two variables, which led to the conclusion of allometry with a coefficient of 2/3 or 3/4. The use of the bilogarithmic equation for estimating the allometry exponent is criticized, and in its place the concept of bidimensional structural relationship (Jolicoeur & Heusner 1971) is advocated. Implications of this concept are developed. A wide range of the coefficients of variation of both VO 2 max and body weight is demonstrated in human populations. It is concluded that no departure from isometry has ever been validly proven in any adult population. The use of muscle mass instead of body weight in the ratio would not improve this lack of validity.