Partitioning locomotor energy use among and within muscles Muscle blood flow as a measure of muscle oxygen consumption

Abstract

SUMMARY Linking the mechanics and energetics of locomotion in vertebrates has been hampered by a lack of information regarding the energy use of individual skeletal muscles in vivo. Here, we present a review of the available data concerning the relationship between the rates of skeletal muscle blood flow and oxygen consumption(V̇O2). In active muscle, during aerobically supported exercise, there is a linear relationship between these variables, irrespective of the muscle fiber type and intensity of exercise through most of the aerobic exercise range. We conclude that the rate of blood flow is the best available indicator of aerobic metabolic rate in multiple individual muscles or regions of muscles during locomotion. The practical considerations of using the injectable microsphere technique to measure muscle blood flow in this context are discussed.

The cost of running uphill: linking organismal and muscle energy use in guinea fowl (Numida meleagris)

“…The rate of total blood flow to the leg muscles during level running at 1.5·m·s -1 and ~2.4·m·s -1 are, likewise, similar to those obtained previously (Ellerby et al, 2005) on comparably sized guinea fowl. Importantly, the increases in metabolic rate and total blood flow to the leg muscles are proportional (Fig.·3), which is consistent with the view that blood flow is a reliable indicator of skeletal muscle metabolic rate (Ellerby et al, 2005;Marsh and Ellerby, 2006). Examining the contribution of individual muscles with statistically significant increases in flow allowed † Swing and stance phase muscle groups: the increases in flow to all but one muscle complex were assigned to either swing or stance, as indicated in Table·1.…”

“…We estimated the metabolic energy used by the individual hindlimb muscles of guinea fowl running both on the level and uphill using whole body oxygen consumption and regional blood flow measurements (Marsh et al, 2004;Ellerby et al, 2005;Marsh and Ellerby, 2006). Our goal was, firstly, to determine which muscles are responsible for the elevated metabolic cost of running uphill over that of level running at the same speed and, secondly, to compare these muscles to those responsible for a similar increase in metabolic cost due solely to an increase in level running speed.…”

Mono-versusbiarticular muscle function in relation to speed and gait changes:in vivoanalysis of the goat triceps brachii

“…Marsh and Ellerby, 2006;Taylor, 1994). Morphological factors that reduce the effects of increased locomotor speed on muscle force and work output can help to reduce the energy cost of increased locomotor speed for the animal and thus may increase sustainable speeds obtainable for a given V O2,max .…”

Field swimming behavior in largemouth bass deviates from predictions based on economy and propulsive efficiency

“…Locomotor costs dominate the daily energy budgets of many species (Kerr, 1982;Boisclair and Sirois, 1993;Irschick and Garland, 2001), and sustained locomotor behaviors may therefore experience selection pressures favoring cost reduction (Schmidt-Nielsen, 1972;Charnov, 1976;Mittelbach, 1981). In terrestrial limbed locomotion, energy costs are primarily associated with weight support and limb segment motion (Marsh and Ellerby, 2006;Pontzer, 2005;Taylor et al, 1980), while in swimmers and fliers the power costs of transferring momentum to the external medium predominate (Gerry and Ellerby, 2014;Morris et al, 2010). Cost reduction in swimmers and fliers can therefore be achieved through locomotor strategies that enable efficient lift and thrust production or by adopting speeds that minimize the energy expended in traveling a unit distance (Pennycuick, 2001).…”