Abstract
The energy cost is compared between running in two and four legged animals. In seven species of birds (0.04 to 22 kg), steady state oxygen consumption during running at various speeds increased linearly with running speed. The slope (E[run]) of the regression line was a constant for each species, but smaller birds had a steeper slope than larger birds (as previously reported for mammals). E(run) values for two legged and four legged runners plotted on logarithmic coordinates against body weight fall along two different straight lines. E(run) decreases more rapidly with body weight in four legged than in two legged runners. The lines cross at about 1 kg body wt. Thus for small body size (<100 g) the predicted cost of transport is significantly less for two legged than for four legged runners. For large body size (>5 kg) the opposite is true. For an animal the size of man, two legged running is energetically over twice as expensive as four legged running.
Original language | English |
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Pages (from-to) | 1038-1044 |
Number of pages | 7 |
Journal | American Journal of Physiology |
Volume | 227 |
Issue number | 5 |
DOIs | |
State | Published - 1 Jan 1974 |
Externally published | Yes |
ASJC Scopus subject areas
- Physiology (medical)