A theory for normalizing resting .VO(2) for differences in body size.
OBJECTIVE
The purpose of this paper was two-fold: 1) to present a method of normalizing data for differences in body size that is consistent with the dimensional relationship between mass and power, and can be universally applied to subjects of any age, sex, or size without statistical cross-validation; and 2) to apply the model to data gathered from boys, girls, men, and women to determine whether or not age- and sex-dependent differences in resting .VO(2) exist.


METHODS
Mass, percent body fat, and resting .VO(2) were measured in 39 boys, 40 girls, 40 men, and 40 women.


RESULTS
Dimensional analysis predicted .VO(2) = a fat-free mass (FFM)2/3, with a defined as the size-independent metabolism of FFM. Bivariate correlation revealed the association between .VO(2) and FFM in children was consistent with biological similarity but not in men and women. Group mean .VO(2).FFM(-2/3) (mL.min(-1).kg(-2/3)) was significantly greater in children (21.7 +/- 2.62) than adults (16.7 +/- 2.30). Also, .VO(2).FFM(-2/3) of female subjects was significantly lower than male subjects in children (girls: 21.0 +/- 2.46; boys: 22.5 +/- 2.61) and adults (women: 15.0 +/- 2.39; men: 16.5 +/- 2.21).


CONCLUSIONS
The dimensional paradigm indicated that mass exponents not equal to 2/3 simultaneously factor out size-dependent and size-independent differences that accompany differences in size. Therefore, size-independent comparisons can only be made using the theoretical mass exponent of 2/3. Also, the experimental results indicated that structural changes accompanying growth must be different from those hypothesized to be the cause of 3/4 scaling in adult animals of different size and species.
McCann
Daniel J
DJ
Department of Exercise Science, Gonzaga University, Spokane, WA 99258-0004, USA. mccann@gonzaga.edu
Adams
William C
WC
D000328:Adult; D000367:Age Factors; D000368:Aged; D001481:Basal Metabolism / Q000502:physiology*; D001823:Body Composition / Q000502:physiology; D001824:Body Constitution / Q000502:physiology*; D002648:Child; D002675:Child, Preschool; D003627:Data Interpretation, Statistical; D004734:Energy Metabolism; D015444:Exercise / Q000502:physiology*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D008962:Models, Theoretical; D010101:Oxygen Consumption / Q000502:physiology*; D011446:Prospective Studies; D012494:Sampling Studies; D012680:Sensitivity and Specificity; D012737:Sex Factors