Weibel 2004 Respir Physiol Neurobiol
|Weibel ER, Bacigalupe LD, Schmitt B, Hoppeler H (2004) Allometric scaling of maximal metabolic rate in mammals: muscle aerobic capacity as determinant factor. Respir Physiol Neurobiol 140:115-32.|
Abstract: Maximal metabolic rate (MMR) of mammals scales differently from basal metabolic rate (BMR). This is first shown by scrutinizing data reported on exercise-induced VO2max in 34 eutherian mammalian species covering a body mass range of 7 g-500 kg. VO2max was found to scale with the 0.872 (+/-0.029, 95 % confidence limits 0.813-0.932) power of body mass which is significantly different from the 3/4 power reported for basal metabolic rate. The aerobic scope is higher in athletic than non-athletic species, and it is also higher in large than in small species. Integrated structure-function studies on a subset of 11 species (body mass 20 g-450 kg) show that the variation of VO2max with body size is tightly associated with the aerobic capacity of the locomotor musculature: the scaling exponents for VO2max, the total volume of mitochondria, and the volume of capillaries are nearly identical. The higher VO2max of athletic species is tightly linked to proportionally larger mitochondrial and capillary volumes in animals of the same size class. As a result VO2max is linearly related to both total mitochondrial and capillary erythrocyte volumes. We conclude that the scaling of maximal metabolic rate is explained by features and mechanisms different from those determining basal metabolic rate.
• Bioblast editor: Gnaiger E
Labels: MiParea: Respiration, mt-Biogenesis;mt-density, Comparative MiP;environmental MiP, Exercise physiology;nutrition;life style
Tissue;cell: Skeletal muscle