Emerging Technologies for Nutrition Research Potential for Assessing Military Performance Capability (1997) / Chapter Skim
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Pages 315-344
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Emerging Technologies for Nutrition Research, 1997 Pp.
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dose-response relationships of walking and running to macronutrient requirements, weight control, physical fitness, and the incidence of disease and injury. The first of the following sections describes FCM technology and some potential applications.
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digital converter, and a microcontroller (microprocessor, memory, real time clock, and interface)
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Figure 14-2 Relationship of measured metabolic cost of locomotion and the estimated metabolic cost of locomotion. Estimated Mloco was calculated using the equation Mloco = 3.702(Wb/tc)
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heat strain prediction models (Kraning, 1991)
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intensity of walking or running exercise. Second, the relationship of heart rate to the Mloco estimated by the FCM method can be used to improve the effectiveness of aerobic training programs.
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also is needed in studies of the etiology of running injuries (van Mechelen, 1992)
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terrestrial animals that run (Figure 14-3) and established the linear increase in metabolic rate with running speed as the first fundamental principle of the energetics of terrestrial locomotion (Taylor et al., 1970, 1982)
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Figure 14-4 The cost of transport (the slope of the relationship between oxygen consumption and running speed) is higher in small animals than in large, scaling with body mass to the -0.30 power.
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muscle. In fact, at high speeds, the efficiency reached 70 percent, roughly three times the maximal value for isolated muscle.
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needed before the mechanical tasks performed by the running muscles that required metabolic energy could be identified. Generating Force to Support the Weight of the Body The lack of definitive answers from measurements of the mechanical work of running and further consideration of running mechanics prompted C
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person or animal by a percentage of its body weight ought to alter the metabolic cost by some lesser factor. However, this was not the case under any of the conditions.
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Figure 14-5 Step length is the horizontal distance moved by the center of mass while a single foot is in contact with the ground. SOURCE: Wright (1995)
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Insights from Changing Contact Times What then dictated the lengths of the steps and contact times that were naturally selected at any running speed? Again, the answer was provided by human experiments in which the naturally chosen frequencies during running and hopping were altered (Farley and Gonzalez, 1996; Farley et al., 1991)
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had to support the weight of the body in a shorter period of time. The increase in metabolic cost when humans ran at higher-than-preferred frequencies was directly related to the decreased period of contact during which the muscles developed vertical force (Farley and Gonzalez, 1996)
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Figure 14-7 Whether running speed is increased by increasing stride length (period of zero force) or stride frequency (frequency of force pulses)
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equivalent. If running faster was achieved through shortening the muscles faster, as Hill had suggested, the metabolic cost of force generation also should increase as it did in isolated muscle, but this was not the case.
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Figure 14-8 The effective mechanical advantage (EMA) , the ratio of ground reaction force to muscle force, is determined by the ratio of the muscle moment arm (r)
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• running and low-intensity walking is unique among ambulatory monitors. This method offers new opportunities to study activity patterns in aged, handicapped, and sedentary humans.
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and (3) to compare Mloco estimates by the FCM method with those measured by heart rate, doubly labeled water, and other methods.
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Brownell, K.D., A.A. Stunkard, and J.M.
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Heglund, N.C., M.A. Fedak, C.R.
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Paffenbarger, R.S., R.T.
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Taylor, C.R., N.C. Heglund, and G.M.O.
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REED HOYT: I will pass one around. The one that is coming around is just standard type technology.
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Tell us how you see this evolving. Give us your thoughts about the next 10 or 15 years of development, because clearly the electronics are available and a lot of other stuff is available, too.
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REED HOYT: Well, I think it is easy enough to make them waterproof. There has been a variety of work done on effects of substrate on energy requirements, and postholing through the snow or walking around on loose sand or walking in water up to your knees certainly is going to have an energy cost associated with it that will not necessarily be dealt with by this device.
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right now in systems is because the companies who have the ability to make them do not do so until they see a market for them. The real issues are, what do you measure physiologically that is scientifically valid, and what are the countermeasures?
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body temperature, has a signal that goes approximately a yard and they are concerned, so with these more powerful systems you have that as a general concern.
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