Energy Cost of Exercise, Postexercise Metabolic Rates, and Obesity

2014 ◽  
pp. 281-292
Author(s):  
Einat Shalev-Goldman ◽  
Trevor O’Neill ◽  
Robert Ross
Keyword(s):  
2006 ◽  
Vol 100 (2) ◽  
pp. 390-398 ◽  
Author(s):  
Raymond C. Browning ◽  
Emily A. Baker ◽  
Jessica A. Herron ◽  
Rodger Kram

The metabolic energy cost of walking is determined, to a large degree, by body mass, but it is not clear how body composition and mass distribution influence this cost. We tested the hypothesis that walking would be most expensive for obese women compared with obese men and normal-weight women and men. Furthermore, we hypothesized that for all groups, preferred walking speed would correspond to the speed that minimized the gross energy cost per distance. We measured body composition, maximal oxygen consumption, and preferred walking speed of 39 (19 class II obese, 20 normal weight) women and men. We also measured oxygen consumption and carbon dioxide production while the subjects walked on a level treadmill at six speeds (0.50–1.75 m/s). Both obesity and sex affected the net metabolic rate (W/kg) of walking. Net metabolic rates of obese subjects were only ∼10% greater (per kg) than for normal-weight subjects, and net metabolic rates for women were ∼10% greater than for men. The increase in net metabolic rate at faster walking speeds was greatest in obese women compared with the other groups. Preferred walking speed was not different across groups (1.42 m/s) and was near the speed that minimized gross energy cost per distance. Surprisingly, mass distribution (thigh mass/body mass) was not related to net metabolic rate, but body composition (% fat) was ( r2 = 0.43). Detailed biomechanical studies of walking are needed to investigate whether obese individuals adopt novel energy saving mechanisms during walking.


1998 ◽  
Vol 76 (6) ◽  
pp. 1091-1097 ◽  
Author(s):  
P J Pekins ◽  
K S Smith ◽  
W W Mautz

Gestation in white-tailed deer (Odocoileus virginianus) of northern regions occurs throughout winter, when foragequantity and quality are limited. Our objective was to measure the energy cost of gestation during winter and spring in order todetermine its impact on energy balance of deer. We used indirect respiration calorimetry to measure the metabolism of 21pregnant deer every 2–4 weeks during gestation (January–May). Fasting metabolic rates (FMR) were used to develop apredictive equation to evaluate temporal energy costs. A measurable increase in metabolism occurred on day 91 of gestation.FMR (kJ/kg body mass (BM)0.75 per day) of pregnant deer rose curvilinearly (FMR = 0.02(days)2 – 3.261(days) + 465.2), with92.2% of the increase occurring in the third trimester; costs were 45% greater in the last trimester for pregnant than fornonpregnant deer. Peak FMR of pregnant deer at 200 days gestation was 617 kJ/kg BM 0.75 per day, 84% above that ofnonpregnant deer (335 kJ/kg BM 0.75 per day). The total energy cost of gestation, in terms of FMR, was 78 004 kJ/kg BM 0.75 per200 days, a 16.4% increase above that of nonpregnant deer. The temporal increase in energy costs was correlated with springgreen-up, indicating important relationships between energy demands, food quality and availability, spring weather, andphysiological adaptations in deer.


1976 ◽  
Vol 33 (11) ◽  
pp. 2443-2449 ◽  
Author(s):  
John F. Schalles ◽  
Thomas E. Wissing

Experiments were designed to evaluate the effects of five dry pellet diets containing various protein levels on metabolic rates and energy cost of food utilization of bluegill (Lepomis macrochirus). In the 48-h period after feeding metabolic rates increased an average of 57% above base levels established prior to food presentation. The energy cost of food utilization, estimated as a percentage of ingested food energy, was [Formula: see text] (range 7.5–32.3%). Positive correlation was found between protein and caloric intakes and the increases in O2 consumption observed after feeding. Percent protein in the diet had no significant effect on mean values of O2 consumption after feeding or the estimates of the energy cost of food utilization. Probably the calorigenic effect of protein in fishes, which are principally ammonotelic, is considerably lower than that observed in ureotelic and uricotelic vertebrates. The mean estimate (14.90% of ingested energy) for the bluegill could reflect a low specific dynamic action of protein in conjunction with the calorigenic effect of the carbohydrate and lipid components of the diets.


2011 ◽  
Vol 7 (5) ◽  
pp. 793-795 ◽  
Author(s):  
Christian C. Voigt ◽  
Karin Schneeberger ◽  
Silke L. Voigt-Heucke ◽  
Daniel Lewanzik

Similar to insects, birds and pterosaurs, bats have evolved powered flight. But in contrast to other flying taxa, only bats are furry. Here, we asked whether flight is impaired when bat pelage and wing membranes get wet. We studied the metabolism of short flights in Carollia sowelli , a bat that is exposed to heavy and frequent rainfall in neotropical rainforests. We expected bats to encounter higher thermoregulatory costs, or to suffer from lowered aerodynamic properties when pelage and wing membranes catch moisture. Therefore, we predicted that wet bats face higher flight costs than dry ones. We quantified the flight metabolism in three treatments: dry bats, wet bats and no rain, wet bats and rain. Dry bats showed metabolic rates predicted by allometry. However, flight metabolism increased twofold when bats were wet, or when they were additionally exposed to rain. We conclude that bats may not avoid rain only because of sensory constraints imposed by raindrops on echolocation, but also because of energetic constraints.


2020 ◽  
Vol 16 (12) ◽  
pp. e1008460
Author(s):  
Adam MR de Graff ◽  
David E. Mosedale ◽  
Tilly Sharp ◽  
Ken A. Dill ◽  
David J. Grainger

Because a cell must adapt to different stresses and growth rates, its proteostasis system must too. How do cells detect and adjust proteome folding to different conditions? Here, we explore a biophysical cost-benefit principle, namely that the cell should keep its proteome as folded as possible at the minimum possible energy cost. This can be achieved by differential expression of chaperones–balancing foldases (which accelerate folding) against holdases (which act as parking spots). The model captures changes in the foldase-holdase ratio observed both within organisms during aging and across organisms of varying metabolic rates. This work describes a simple biophysical mechanism by which cellular proteostasis adapts to meet the needs of a changing growth environment.


1970 ◽  
Vol 126 (3) ◽  
pp. 526a-526 ◽  
Author(s):  
A. N. Goldbarg
Keyword(s):  

IEE Review ◽  
1993 ◽  
Vol 39 (2) ◽  
pp. 66
Author(s):  
R. Alan Davis

1970 ◽  
Vol 64 (2) ◽  
pp. 347-358
Author(s):  
A. Stanley Weltman ◽  
Arthur M. Sackler

ABSTRACT Body weight, metabolic rate, locomotor activity and alterations in endocrine organ activity were noted in recessive homozygous male whirler mice and the phenotypically »normal« heterozygotes. Representative populations of the two types were studied at different age levels. In general, body weights of the whirler mice were consistently and significantly lower. Open-field locomotion studies similarly indicated heightened locomotor activity. Total leukocyte and eosinophil counts were either markedly or significantly lower in the homozygous vs. heterozygous whirler groups. Evaluation of relative organ weights showed significantly increased adrenal weights in whirler mice sacrificed at 14 weeks and 11 months of age. These changes were accompanied by involution of the thymus. Thus, the varied data indicate persistent increased metabolism and adrenocortical activity during the life-span of the whirler mice. Seminal vesicle weight decreases in the whirler males at 11 months suggest lower gonadal function. The findings are in accord with previous studies of alterations in metabolic rates and endocrine function of homozygous whirler vs. heterozygous female mice.


2003 ◽  
Vol 97 (6) ◽  
pp. 639 ◽  
Author(s):  
LORAN D. ERDMANN
Keyword(s):  

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