Flight energetics of sphinx moths: power input during hovering flight

1976 ◽  
Vol 64 (3) ◽  
pp. 529-543 ◽  
Author(s):  
T. M. Casey
Keyword(s):  
Energy Expenditure ◽  
Body Mass ◽  
Power Input ◽  
Unit Mass ◽  
Energetic Cost ◽  
Wing Loading ◽  
Mean Power ◽  
Hovering Flight ◽  
Blade Element Theory ◽  
Deilephila Elpenor

The energetic cost of hovering flight was measured in sphinx moths from five species. Mean power input per unit mass (Pi/M) varied from 237–2 W kg-1 in Manduca sexta (Subfamily:Sphinginae), mean body mass 1-2 X 10(−3) kg, to 327-9 W kg-1 in Deilephila elpenor (Subfamily: Macroglossinae) mean body mass 7-3 X 10(−4) kg. Mean Pi/M for the five species was inversely proportional to mean body mass and directly proportional to mean wing loading. For any given body mass, Pi/M was greater in Hyles lineata than in M. sexta. This difference is correlated with higher wing loading at any given mass in H. lineata. Energy expenditure per unit mass of thorax was 1018 W kg-1 in H. lineata and 694 W kg-1 in M. sexta. Within each of these species, Pi per unit mass of thorax does not vary with body mass. Power input data are compared with calculated power requirements based on momentum theory and blade-element theory of helicopter aerodynamics. Absolute efficiency, the ratio between calculated power requirements and measured energy expenditure, appears to vary directly with body mass. These data provide an energetic basis for observed correlates between thoracic temperature and flight effort in flying sphinx moths.

scholarly journals Determinants of climbing energetic costs in humans

2021 ◽  
Author(s):  
Elaine E. Kozma ◽  
Herman Pontzer
Keyword(s):  
Body Size ◽  
Energy Expenditure ◽  
Body Mass ◽  
Anatomical Variation ◽  
Negligible Effect ◽  
Energetic Cost ◽  
Energetic Costs ◽  
Cost Of Transport ◽  
Specific Cost ◽  
Limb Proportions

Previous studies in primates and other animals have shown that mass specific cost of transport (J kg−1 m−1) for climbing is independent of body size across species, but little is known about within-species allometry of climbing costs or the effects of difficulty and velocity. Here, we assess the effects of velocity, route difficulty, and anatomical variation on the energetic cost of climbing within humans. Twelve experienced rock climbers climbed on an indoor wall over a range of difficulty levels and velocities, with energy expenditure measured via respirometry. We found no effect of body mass or limb proportions on mass-specific cost of transport among subjects. Mass-specific cost of transport was negatively correlated with climbing velocity. Increased route difficulty was associated with slower climbing velocities and thus higher costs, but there was no statistically significant effect of route difficulty on energy expenditure independent of velocity. Finally, human climbing costs measured in this study were similar to published values for other primates, suggesting arboreal adaptations have a negligible effect on climbing efficiency.

Nonexercise movement in elderly compared with young people

2007 ◽  
Vol 292 (4) ◽  
pp. E1207-E1212 ◽  
Author(s):  
Ann M. Harris ◽  
Lorraine M. Lanningham-Foster ◽  
Shelly K. McCrady ◽  
James A. Levine
Keyword(s):  
Energy Expenditure ◽  
Lean Body Mass ◽  
Body Mass ◽  
The Elderly ◽  
Energetic Cost ◽  
Elderly Subjects ◽  
Older Individuals ◽  
Free Living ◽  
Healthy Elderly ◽  
Young Subjects

The association between free-living daily activity and aging is unclear because nonexercise movement and its energetic equivalent, nonexercise activity thermogenesis, have not been exhaustively studied in the elderly. We wanted to address the hypothesis that free-living nonexercise movement is lower in older individuals compared with younger controls matched for lean body mass. Ten lean, healthy, sedentary elderly and 10 young subjects matched for lean body mass underwent measurements of nonexercise movement and body posture over 10 days using sensitive, validated technology. In addition, energy expenditure was assessed using doubly labeled water and indirect calorimetry. Total nonexercise movement (acceleration arbitrary units), standing time, and standing acceleration were significantly lower in the elderly subjects; this was specifically because the elderly walked less distance per day despite having a similar number of walking bouts per day compared with the young individuals. The energetic cost of basal metabolic rate, thermic effect of food, total daily energy expenditure, and nonexercise activity thermogenesis were not different between the elderly and young groups. Thus, the energetic cost of walking in the elderly may be greater than in the young. Lean, healthy elderly individuals may have a biological drive to be less active than the young.

Energy and protein requirements for molt in the king penguin Aptenodytes patagonicus

1994 ◽  
Vol 266 (4) ◽  
pp. R1182-R1188 ◽  
Author(s):  
Y. Cherel ◽  
J. B. Charrassin ◽  
E. Challet
Keyword(s):  
Energy Expenditure ◽  
Total Energy ◽  
Body Mass ◽  
Dry Mass ◽  
Total Energy Expenditure ◽  
Energetic Cost ◽  
Energetic Efficiency ◽  
Composition Analysis ◽  
Epidermal Structure ◽  
Fasting Duration

Adult king penguins annually fast ashore for 1 mo for molting. By the end of molt, they have lost 44% of their prefasting body mass. About 18% of new feather synthesis occurs at sea, thus reducing both nutrient requirement and fasting duration. Plumage synthesis continues during the first 3 wk of fasting. Loss of old feathers occurs between day 12 and day 21 of the molt, and it is associated with a peak in daily body mass loss. The dry mass of epidermal structure synthesized during molt is 395 g. Body composition analysis indicates that fat oxidation accounts for 85% of total energy expenditure. The proportion for protein is 15%, a value twofold higher than during the breeding (nonmolting) fast. The mean energy expenditure is also 21% higher during the molting fast (3.04 W/kg). Compared with other birds, the energetic cost of feather synthesis is the lowest in king penguins (85 kJ/g) and consequently the energetic efficiency is the highest (25%). Changes in tissue composition during molt show that integument is the main lipid source (72% of the lipid loss) and thus the main source of energy (61% of the total energy expenditure). The integument and the pectoral muscles play a major role in molting protein metabolism, providing 20 and 57%, respectively, of the total protein needs for feather synthesis and/or energy expenditure. This result emphasizes the role of integument as a protein source, because the large premolting muscle hypertrophy is not sufficient to account for the totality of the protein cost of molt.

scholarly journals Effects of Time-Restricted Feeding on Supramaximal Exercise Performance and Body Composition: A Randomized and Counterbalanced Crossover Study in Healthy Men

2021 ◽  
Vol 18 (14) ◽  
pp. 7227
Author(s):  
Joana M. Correia ◽  
Inês Santos ◽  
Pedro Pezarat-Correia ◽  
Cláudia Minderico ◽  
Brad J. Schoenfeld ◽  
...  
Keyword(s):  
Body Composition ◽  
Body Mass ◽  
Exercise Performance ◽  
Fat Free Mass ◽  
Restricted Feeding ◽  
Supramaximal Exercise ◽  
Mean Power ◽  
Post Intervention ◽  
Dietary Record

Using a crossover design, we explored the effects of both short- and long-term time-restricted feeding (TRF) vs. regular diet on Wingate (WnT) performance and body composition in well-trained young men. Twelve healthy male physical education students were included (age: 22.4 ± 2.8 years, height: 174.0 ± 7.1 cm, body mass: 73.6 ± 9.5 kg, body mass index: 24.2 ± 2.0 kg/m2). The order of dieting was randomized and counterbalanced, and all participants served as their own controls. TRF was limited to an 8-h eating window and non-TRF involved a customary meal pattern. Participants performed WnT tests and body composition scans at baseline, post-one and post-four weeks of the assigned diet. Before testing, participants were asked to fill out a dietary record over four consecutive days and were instructed to continue their habitual training throughout the study. Energy intake and macronutrient distribution were similar at baseline in both conditions. WnT mean power and total work output increased post-four weeks of TRF. Both conditions were similarly effective in increasing fat-free mass after four weeks of intervention. However, there was no correlation between change in fat-free mass and WnT mean power after TRF. TRF did not elicit any changes in WnT performance or body composition one week post-intervention. Thus, long-term TRF can be used in combination with regular training to improve supramaximal exercise performance in well-trained men.

scholarly journals The energy allocation trade-offs underlying life history traits in hypometabolic strepsirhines and other primates

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Bruno Simmen ◽  
Luca Morino ◽  
Stéphane Blanc ◽  
Cécile Garcia
Keyword(s):  
Life History ◽  
Energy Expenditure ◽  
Body Mass ◽  
Life History Traits ◽  
Brain Size ◽  
Energy Allocation ◽  
Interbirth Interval ◽  
Energy Investment ◽  
Litter Mass ◽  
Trade Offs

AbstractLife history, brain size and energy expenditure scale with body mass in mammals but there is little conclusive evidence for a correlated evolution between life history and energy expenditure (either basal/resting or daily) independent of body mass. We addressed this question by examining the relationship between primate free-living daily energy expenditure (DEE) measured by doubly labeled water method (n = 18 species), life history variables (maximum lifespan, gestation and lactation duration, interbirth interval, litter mass, age at first reproduction), resting metabolic rate (RMR) and brain size. We also analyzed whether the hypometabolic primates of Madagascar (lemurs) make distinct energy allocation tradeoffs compared to other primates (monkeys and apes) with different life history traits and ecological constraints. None of the life-history traits correlated with DEE after controlling for body mass and phylogeny. In contrast, a regression model showed that DEE increased with increasing RMR and decreasing reproductive output (i.e., litter mass/interbirth interval) independent of body mass. Despite their low RMR and smaller brains, lemurs had an average DEE remarkably similar to that of haplorhines. The data suggest that lemurs have evolved energy strategies that maximize energy investment to survive in the unusually harsh and unpredictable environments of Madagascar at the expense of reproduction.

Speed, stride frequency and energy cost per stride: how do they change with body size and gait?

1988 ◽  
Vol 138 (1) ◽  
pp. 301-318 ◽  
Author(s):  
N. C. Heglund ◽  
C. R. Taylor
Keyword(s):  
Body Size ◽  
Body Mass ◽  
Energy Cost ◽  
Reaction Force ◽  
Stride Frequency ◽  
Energetic Cost ◽  
Published Data ◽  
Frequency Change ◽  
Cost Of Locomotion ◽  
The Cost

In this study we investigate how speed and stride frequency change with body size. We use this information to define ‘equivalent speeds’ for animals of different size and to explore the factors underlying the six-fold difference in mass-specific energy cost of locomotion between mouse- and horse-sized animals at these speeds. Speeds and stride frequencies within a trot and a gallop were measured on a treadmill in 16 species of wild and domestic quadrupeds, ranging in body size from 30 g mice to 200 kg horses. We found that the minimum, preferred and maximum sustained speeds within a trot and a gallop all change in the same rather dramatic manner with body size, differing by nine-fold between mice and horses (i.e. all three speeds scale with about the 0.2 power of body mass). Although the absolute speeds differ greatly, the maximum sustainable speed was about 2.6-fold greater than the minimum within a trot, and 2.1-fold greater within a gallop. The frequencies used to sustain the equivalent speeds (with the exception of the minimum trotting speed) scale with about the same factor, the −0.15 power of body mass. Combining this speed and frequency data with previously published data on the energetic cost of locomotion, we find that the mass-specific energetic cost of locomotion is almost directly proportional to the stride frequency used to sustain a constant speed at all the equivalent speeds within a trot and a gallop, except for the minimum trotting speed (where it changes by a factor of two over the size range of animals studied). Thus the energy cost per kilogram per stride at five of the six equivalent speeds is about the same for all animals, independent of body size, but increases with speed: 5.0 J kg-1 stride-1 at the preferred trotting speed; 5.3 J kg-1 stride-1 at the trot-gallop transition speed; 7.5 J kg-1 stride-1 at the preferred galloping speed; and 9.4 J kg-1 stride-1 at the maximum sustained galloping speed. The cost of locomotion is determined primarily by the cost of activating muscles and of generating a unit of force for a unit of time. Our data show that both these costs increase directly with the stride frequency used at equivalent speeds by different-sized animals. The increase in cost per stride with muscles (necessitating higher muscle forces for the same ground reaction force) as stride length increases both in the trot and in the gallop.

scholarly journals Influence of body composition on physical activity validation studies using doubly labeled water

2004 ◽  
Vol 96 (4) ◽  
pp. 1357-1364 ◽  
Author(s):  
Louise C. Mâsse ◽  
Janet E. Fulton ◽  
Kathleen L. Watson ◽  
Matthew T. Mahar ◽  
Michael C. Meyers ◽  
...  
Keyword(s):  
Physical Activity ◽  
Body Composition ◽  
Energy Expenditure ◽  
Body Mass ◽  
Resting Metabolic Rate ◽  
Fat Free Mass ◽  
Doubly Labeled Water ◽  
Comparison Analysis ◽  
Methods Comparison ◽  
Statistical Procedures

This study investigated the influence of two approaches (mathematical transformation and statistical procedures), used to account for body composition [body mass or fat-free mass (FFM)], on associations between two measures of physical activity and energy expenditure determined by doubly labeled water (DLW). Complete data for these analyses were available for 136 African American (44.1%) and Hispanic (55.9%) women (mean age 50 ± 7.3 yr). Total energy expenditure (TEE) by DLW was measured over 14 days. Physical activity energy expenditure (PAEE) was computed as 0.90 × TEE - resting metabolic rate. During week 2, participants wore an accelerometer for 7 consecutive days and completed a 7-day diary. Pearson's product-moment correlations and three statistical procedures (multiple regressions, partial correlations, and allometric scaling) were used to assess the effect of body composition on associations. The methods-comparison analysis was used to study the effect of body composition on agreement. The statistical procedures demonstrated that associations improved when body composition was included in the model. The accelerometer explained a small but meaningful portion of the variance in TEE and PAEE after body mass was accounted for. The methods-comparison analysis confirmed that agreement with DLW was affected by the transformation. Agreement between the diary (transformed with body mass) and TEE reflected the association that exists between body mass and TEE. These results suggest that the accelerometer and diary accounted for a small portion of TEE and PAEE. Most of the variance in DLW-measured energy expenditure was explained by body mass or FFM.

Serum leptin levels and energy expenditure in normal weight women

1998 ◽  
Vol 76 (2) ◽  
pp. 237-241 ◽  
Author(s):  
L J Martin ◽  
PJH Jones ◽  
R V Considine ◽  
W Su ◽  
N F Boyd ◽  
...  
Keyword(s):  
Body Mass Index ◽  
Food Intake ◽  
Energy Expenditure ◽  
Body Mass ◽  
Body Fat ◽  
Positive Association ◽  
Normal Weight ◽  
Serum Leptin ◽  
Percentage Body Fat ◽  
Healthy Humans

To investigate whether circulating leptin levels are associated with energy expenditure in healthy humans, doubly labeled water energy measurements and food intake assessment were carried out in 27 women (mean age, 48.6 years; weight, 61.9 kg; body mass index, 23.2). Energy expenditure was determined over 13 days. Food intake was measured by 7-day food records. Leptin was measured by radioimmunoassay. Leptin level was strongly associated with percentage body fat (r = 0.59; p < 0.001), fat mass (r = 0.60; p < 0.001), and body mass index (r = 0.41; p = 0.03), but no correlation was observed with energy expenditure (r = 0.02; p = 0.93). After controlling for percentage body fat, a positive association of leptin level with energy expenditure of marginal significance (p = 0.06) was observed. There were no significant univariate associations of age, physical activity, lean body mass, height, or dietary variables with leptin level. When controlling for body fat, a significant positive correlation was observed for percent energy from carbohydrate and negative correlations with dietary fat and alcohol intake. These findings confirm previous associations between leptin and body fat content and suggest a relationship between serum leptin and energy expenditure level in healthy humans.Key words: leptin, energy expenditure, body composition, diet.

Carbohydrate loading failed to improve 100-km cycling performance in a placebo-controlled trial

2000 ◽  
Vol 88 (4) ◽  
pp. 1284-1290 ◽  
Author(s):  
Louise M. Burke ◽  
John A. Hawley ◽  
Elske J. Schabort ◽  
Alan St Clair Gibson ◽  
Iñigo Mujika ◽  
...  
Keyword(s):  
Body Mass ◽  
Muscle Glycogen ◽  
Blood Glucose Concentration ◽  
Controlled Trial ◽  
Liver Glycogen ◽  
Cycling Performance ◽  
Controlled Study ◽  
Mean Power ◽  
Road Racing ◽  
Mean Power Output

We evaluated the effect of carbohydrate (CHO) loading on cycling performance that was designed to be similar to the demands of competitive road racing. Seven well-trained cyclists performed two 100-km time trials (TTs) on separate occasions, 3 days after either a CHO-loading (9 g CHO ⋅ kg body mass− 1 ⋅ day− 1) or placebo-controlled moderate-CHO diet (6 g CHO ⋅ kg body mass− 1 ⋅ day− 1). A CHO breakfast (2 g CHO/kg body mass) was consumed 2 h before each TT, and a CHO drink (1 g CHO ⋅ kg.body mass− 1 ⋅ h− 1) was consumed during the TTs to optimize CHO availability. The 100-km TT was interspersed with four 4-km and five 1-km sprints. CHO loading significantly increased muscle glycogen concentrations (572 ± 107 vs. 485 ± 128 mmol/kg dry wt for CHO loading and placebo, respectively; P < 0.05). Total muscle glycogen utilization did not differ between trials, nor did time to complete the TTs (147.5 ± 10.0 and 149.1 ± 11.0 min; P = 0.4) or the mean power output during the TTs (259 ± 40 and 253 ± 40 W, P = 0.4). This placebo-controlled study shows that CHO loading did not improve performance of a 100-km cycling TT during which CHO was consumed. By preventing any fall in blood glucose concentration, CHO ingestion during exercise may offset any detrimental effects on performance of lower preexercise muscle and liver glycogen concentrations. Alternatively, part of the reported benefit of CHO loading on subsequent athletic performance could have resulted from a placebo effect.

scholarly journals Enhancement of Countermovement Jump Performance Using a Heavy Load with Velocity-Loss Repetition Control in Female Volleyball Players

2021 ◽  
Vol 18 (21) ◽  
pp. 11530
Author(s):  
Michal Krzysztofik ◽  
Rafal Kalinowski ◽  
Robert Trybulski ◽  
Aleksandra Filip-Stachnik ◽  
Petr Stastny
Keyword(s):  
Body Mass ◽  
Repeated Measures ◽  
Performance Enhancement ◽  
Countermovement Jump ◽  
Mean Power ◽  
Mean Velocity ◽  
Heavy Load ◽  
Jump Performance ◽  
Volleyball Players ◽  
Post Hoc

Although velocity control in resistance training is widely studied, its utilization in eliciting post-activation performance enhancement (PAPE) responses receives little attention. Therefore, this study aimed to evaluate the effectiveness of heavy-loaded barbell squats (BS) with velocity loss control conditioning activity (CA) on PAPE in subsequent countermovement jump (CMJ) performance. Sixteen resistance-trained female volleyball players participated in this study (age: 24 ± 5 yrs.; body mass: 63.5 ± 5.2 kg; height: 170 ± 6 cm; relative BS one-repetition maximum (1RM): 1.45 ± 0.19 kg/body mass). Each participant performed two different conditions: a set of the BS at 80% 1 RM with repetitions performed until a mean velocity loss of 10% as the CA or a control condition without CA (CNTRL). To assess changes in jump height (JH) and relative mean power output (MP), the CMJ was performed 5 min before and throughout the 10 min after the CA. The two-way analysis of variance with repeated measures showed a significant main effect of condition (p = 0.008; η2 = 0.387) and time (p < 0.0001; η2 = 0.257) for JH. The post hoc test showed a significant decrease in the 10th min in comparison to the value from baseline (p < 0.006) for the CNTRL condition. For the MP, a significant interaction (p = 0.045; η2 = 0.138) was found. The post hoc test showed a significant decrease in the 10th min in comparison to the values from baseline (p < 0.006) for the CNTRL condition. No significant differences were found between all of the time points and the baseline value for the CA condition. The CA used in the current study fails to enhance subsequent countermovement jump performance in female volleyball players. However, the individual analysis showed that 9 out of the 16 participants (56%) responded positively to the applied CA, suggesting that the PAPE effect may be individually dependent and should be carefully verified before implementation in a training program.

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