Why are the fastest runners of intermediate size? Contrasting scaling of mechanical demands and muscle supply of work and power.

ABSTRACT: The fastest land animals are of intermediate size. Cheetah, antelope, greyhounds and racehorses have been measured running much faster than reported for elephants or elephant shrews. Can this be attributed to scaling of physical demands and explicit physiological constraints to supply? Here, we describe the scaling of mechanical work demand each stride, and the mechanical power demand each stance. Unlike muscle stress, strain and strain rate, these mechanical demands cannot be circumvented by changing the muscle gearing with minor adaptations in bone geometry or trivial adjustments to limb posture. Constraints to the capacity of muscle to supply work and power impose fundamental limitations to maximum speed. Given an upper limit to muscle work capacity each contraction, maximum speeds in b

SUBMITTER: Usherwood JR 

PROVIDER: S-EPMC7655479 | biostudies-literature | 2020 Oct

REPOSITORIES: biostudies-literature