Scaling peak VO2 for differences in body size
Welsman, J.R.; Armstrong, N.; Nevill, A.M.; Winter, E.M.; Kirby, B.J.
Medicine and Science in Sports and Exercise 28(2): 259-265
1996
ISSN/ISBN: 0195-9131 PMID: 8775163 Document Number: 463892
This paper examined the influence of different statistical modeling techniques on the interpretation of peak ovrhdot VO-2 data in groups of prepubertal, circumpubertal, and adult males (group 1M, N = 29; group 2M, N = 26; group 3M, N = 8) and females (group 1F, N = 33; group 2F, N = 34; group 3F, N = 16). Conventional comparisons of the simple per-body-mass ratio (ml cntdot kg-1 cntdot min-1) revealed no significant differences between the three male groups (P lt 0.05). In females, a decline in ovrhdot VO-2 between group 2F and 3F was observed (P lt 0.05). Both linear and log-linear (allometric) models revealed significant increases across all three male groups for peak ovrhdot VO-2 adjusted for body mass (P lt 0.05). In females these scaling models identified a significantly lower peak ovrhdot VO-2 in group IF versus groups 2F and 3F (P lt 0.05). Based upon the common mass exponent identified (b = 0.80, SE = 0.04), power function ratios (y cntdot mass-0.80) were generated and the logarithms of these compared. Again, results indicated a progressive increase in peak ovrhdot VO-2 across groups 1M to 3M (P lt 0.05) and an increase between groups IF and 2F (P lt 0.05). Incorporating stature into the allometric equation reduced the mass exponent to 0.71 (SE = 0.06) with the contribution of the stature exponent shown to be 0.44 (SE = 0.20). These results indicate that conventional ratio standards do not adequately account for body size differences when investigating functional changes in peak ovrhdot VO-2.