Metabolic cost of grade running in dogs

Abstract

Dogs (Canis familiaris) were run up and down 7.4, 11.8, and 20.4% grades as well as on the horizontal at speeds of 3 and 6 km/h while their steady-state oxygen comsumption was measured. On positive grades the metabolism was directly dependent on both grade and speed. On the negative grades the metabolic rates were dependent only on speed and for each dog were depressed about the same amount below the metabolism needed for horizontal running at each speed. The clustering of the metabolic rates for the downhill slopes means that to cover a given distance gorizontally and downhill the dog will use the minimum energy if it descends via the gentlest grade. This is so because such a route allows the animal to maintain the lowest metabolism for the longest time. There is no best uphill route. The grade metabolism of the dogs was an almost exact duplicate of that found for humans running on grades which implies similarity of mechanical and biochemical aspects of running.

The metabolic cost of walking on gradients with a waddling gait

“…Although there are exceptions (Yousef et al, 1972), V O2 also generally decreases with a steepening decline (Cohen et al, 1978). The saving in metabolic costs when descending relative to locomotion on a horizontal surface tends not to be as great in absolute terms as the increased costs associated with ascending a slope of a similar angle (Armstrong et al, 1983;Cohen et al, 1978;Raab et al, 1976;Robbins et al, 1979;Taylor et al, 1972;White and Yousef, 1978). This implies that the wholeanimal mechanical efficiency (mechanical work done/chemical energy consumed) is lower on declines.…”

“…Although there are notable exceptions -the marabou stork Leptoptilos crumeniferus (Bamford and Maloiy, 1980), cockroach Gromphadorhina portento (Herreid et al, 1981) and ant Camponotus sp. (Lipp et al, 2005) -generally, for most species, as gradient increases so does V O2 at all locomotory speeds (Bedford et al, 1979;Brooks and White, 1978;Chassin et al, 1976;Clapperton, 1964;Cohen et al, 1978;Eaton et al, 1995;Ellerby et al, 2003;Full and Tullis, 1990;Raab et al, 1976;Robbins et al, 1979;Wunder and Morrison, 1974;Yousef et al, 1972). The relative cost of ascending or descending a gradient may also be size dependent, with a lower percentage increase or decrease (compared with locomotion on the level) of locomoting uphill or downhill, respectively, for smaller animals (Taylor et al, 1972).…”

“…Additional muscle activity means that whole-animal metabolic costs (rate of O 2 consumption, V O2 ) should also increase (Ellerby et al, 2003), assuming that additional costs are met aerobically. Accordingly, increased metabolic costs were found in birds (Bamford and Maloiy, 1980;Ellerby et al, 2003;Rubenson et al, 2006;Snyder and Carello, 2008;Warncke et al, 1988), humans (Dill, 1965;Margaria et al, 1963;Minetti et al, 2002;Yousef et al, 1972), a range of quadrupeds (Armstrong et al, 1983;Bedford et al, 1979;Brooks and White, 1978;Chassin et al, 1976;Clapperton, 1964;Cohen et al, 1978;Eaton et al, 1995;Farley and Emshwiller, 1996;McDonough et al, 2002;Raab et al, 1976;Robbins et al, 1979;Snyder and Carello, 2008;Taylor et al, 1972;White and Yousef, 1978;Wickler et al, 2000;Wickler et al, 2003;Wunder and Morrison, 1974;Yousef et al, 1972) and invertebrates (Full and Tullis, 1990;Tullis and Andrus, 2011) when ascending gradients. Although there are notable exceptions -the marabou stork Leptoptilos crumeniferus (Bamford and Maloiy, 1980), cockroach Gromphadorhina portento (Herreid et al, 1981) and ant Camponotus sp.…”

“…Most empirical studies have recorded reduced metabolic costs for animals descending declines (Armstrong et al, 1983;Byrnes et al, 1985;Cohen et al, 1978;Margaria et al, 1963;Minetti et al, 2002;Raab et al, 1976;Robbins et al, 1979;Taylor et al, 1972;White and Yousef, 1978;Yousef et al, 1972). Ants are an exception, but this may be due to the resolution of the respirometry equipment not allowing detection of the small differences expected in very small animals (Lipp et al, 2005).…”

Comparative Physiology of Fatigue

“…It is also about the same as a racing-fit thoroughbred race horse, but only 45% of the most highly aerobic mammal known, the 1.5-g Etruscan shrew. The efficiencies with which kangaroos hopped uphill were equivalent to those of dogs running up an equivalent grade (61). The EMA of kangaroos was constant at all speeds and has been shown to be constant and invariant with body size (7) in macropods, which is different than that in eutherians (members of the mammalian clade Eutheria, of which all living members are placental mammals, unlike marsupials) in which it changes regularly with size.…”