scholarly journals Physiomorphic Transformation in Extreme Endurance Migrants: Revisiting the Case of Bar-Tailed Godwits Preparing for Trans-Pacific Flights

2021 ◽  
Vol 9 ◽  
Author(s):  
Theunis Piersma ◽  
Robert E. Gill ◽  
Daniel R. Ruthrauff

In a 1998 paper entitled “Guts don’t fly: small digestive organs in obese bar-tailed godwits,” Piersma and Gill (1998) showed that the digestive organs were tiny and the fat loads huge in individuals suspected of embarking on a non-stop flight from Alaska to New Zealand. It was suggested that prior to migratory departure, these godwits would shrink the digestive organs used during fuel deposition and boost the size and capacity of exercise organs to optimize flight performance. Here we document the verity of the proposed physiomorphic changes by comparing organ sizes and body composition of bar-tailed godwits Limosa lapponica baueri collected in modesty midway during their fueling period (mid-September; fueling, n = 7) with the previously published data for godwits that had just departed on their trans-Pacific flight (October 19; flying, n = 9). Mean total body masses for the two groups were nearly identical, but nearly half of the body mass of fueling godwits consisted of water, while fat constituted over half of total body mass of flying godwits. The two groups also differed in their fat-free mass components. The heart and flight muscles were heavier in fueling godwits, but these body components constituted a relatively greater fraction of the fat-free mass in flying godwits. In contrast, organs related to digestion and homeostasis were heavier in fueling godwits, and most of these organ groups were also relatively larger in fueling godwits compared to flying godwits. These results reflect the functional importance of organ and muscle groups related to energy acquisition in fueling godwits and the consequences of flight-related exertion in flying godwits. The extreme physiomorphic changes apparently occurred over a short time window (≤1 month). We conclude that the inferences made on the basis of the 1998 paper were correct. The cues and stimuli which moderate these changes remain to be studied.

2017 ◽  
Vol 38 (12) ◽  
pp. 890-896
Author(s):  
Helouane Ázara ◽  
Paulo Farinatti ◽  
Adrian Midgley ◽  
Fabrício Vasconcellos ◽  
Patrícia Vigário ◽  
...  

AbstractThe main purpose of the present study was to compare the reference metabolic equivalent (MET) value and observed resting oxygen uptake (VO2) for defining cardiorespiratory fitness (VO2max) and characterizing the energy cost of treadmill running. A heterogeneous cohort of 114 healthy men volunteered to participate. In Part 1 of the study, 114 men [mean±SD, age: 24±5 years; height: 177.1±7.9 cm; body mass: 75.0±10.0 kg] visited the laboratory twice for assessment of resting and maximal VO2 values to compare the reference MET value vs. observed resting VO2 and to investigate the association between resting VO2 and VO2max. In Part 2, 14 of the 114 men visited the laboratory once more to perform a 30-min bout of running at 8.0 km∙h−1/8.3 METs. The mean observed resting VO2 of 3.26 mL·kg−1·min−1 was lower than the reference MET value of 3.5 mL·kg−1·min−1 (P<0.001). Resting and maximal VO2 values relative to total body mass and fat-free mass were positively correlated (R=0.71 and 0.60, respectively; P<0.001). The maximal MET and energy cost of treadmill running were consequently underestimated when calculated using the reference MET value only for those with low VO2max (P=0.005 to P<0.001). In conclusion, the reference MET value considerably overestimated observed resting VO2 in men with low VO2max, resulting in underestimations of the maximal MET, exercise intensity prescription, and the energy cost of running.


2003 ◽  
Vol 94 (6) ◽  
pp. 2368-2374 ◽  
Author(s):  
Marjolein Visser ◽  
Marco Pahor ◽  
Frances Tylavsky ◽  
Stephen B. Kritchevsky ◽  
Jane A. Cauley ◽  
...  

Changing body composition has been suggested as a pathway to explain age-related functional decline. No data are available on the expected changes in body composition as measured by dual-energy X-ray absorptiometry (DXA) in a population-based cohort of older persons. Body composition data at baseline, 1-yr follow-up, and 2-yr follow-up was measured by DXA in 2,040 well-functioning black and white men and women aged 70–79 yr, participants of the Health, Aging, and Body Composition Study. After 2 yr, a small decline in total body mass was observed (men: −0.3%, women: −0.4%). Among men, fat-free mass and appendicular lean soft tissue mass (ALST) decreased by −1.1 and −0.8%, respectively, which was masked by a simultaneous increase in total fat mass (+2.0%). Among women, a decline in fat-free mass was observed after 2 yr only (−0.6%) with no change in ALST and body fat mass. After 2 yr, the decline in ALST was greater in blacks than whites. Change in total body mass was associated with change in ALST ( r = +0.58 to +0.70; P < 0.0001). Among participants who lost total body mass, men lost relatively more ALST than women, and blacks lost relatively more ALST than whites. In conclusion, the mean change in body composition after a 1- to 2-yr follow-up was 1–2% with a high interindividual variability. Loss of ALST was greater in men compared with women, and greater in blacks compared with whites, suggesting that men and blacks may be more prone to muscle loss.


2019 ◽  
Vol 4 ◽  
pp. 105 ◽  
Author(s):  
Linda M. O'Keeffe ◽  
Abigail Fraser ◽  
Laura D. Howe

Correlations of body composition with height vary by age and sex during childhood. Standard approaches to accounting for height in measures of body composition (dividing by height (in meters)2) do not take this into account. Using measures of total body mass (TBM), fat mass (FM) and fat free mass (FFM) at ages nine, 11, 13, 15 and 18 years from a longitudinal UK cohort study (ALSPAC), we calculated indices of body composition at each age by dividing measures by height (in meters)2. We then produced age-and sex-specific powers of height using allometric regressions and calculated body composition indices by dividing measures by height raised to these powers. TBM, FM and FFM divided by height2 were correlated with height up-to age 11 in females. In males, TBM and FM divided by height2 were correlated with height up-to age 15 years while FM divided by height2 was correlated with height up-to age 11 years. Indices of body composition using age-and sex-specific powers were not correlated with height at any age. In early life, age-and sex-specific powers of height, rather than height in meters2, should be used to adjust body composition for height when measures of adiposity/mass independent of height are required.


2001 ◽  
Vol 49 (12) ◽  
pp. 1633-1640 ◽  
Author(s):  
Ursula G. Kyle ◽  
Laurence Genton ◽  
Didier Hans ◽  
Veronique L. Karsegard ◽  
Jean-Pierre Michel ◽  
...  

Circulation ◽  
2018 ◽  
Vol 137 (suppl_1) ◽  
Author(s):  
Philimon N Gona ◽  
Jane J Lee ◽  
Carol J Salton ◽  
Saadia Qazi ◽  
Christopher J O'Donnell ◽  
...  

Introduction: Increased left ventricular mass (LVM) predicts excess cardiovascular morbidity and mortality. LVM is often indexed to height (HT) or body surface area (BSA). HT-indexation ignores weight and thus obesity. The relationship of indexed LVM with weight, obesity, and adiposity is unclear. We investigated the association of LVM with total-body mass (TBM, i.e. weight) and fat-free mass (FFM), hypothesizing that LVM scales better to FFM than TBM. Methods: From the 1794 members of Framingham Offspring cohort who underwent cardiac magnetic resonance (CMR), we identified 845 (aged 65±9y) without any history of hypertension, myocardial infarction, heart failure, or CMR wall-motion abnormality. LVM was measured from cine bSSFP images and indexed to HT, BSA, TBM and FFM (by DEXA). Participants were stratified by sex and body mass index (BMI) category (NL=BMI 18.5 - 24.9; OW=25.0 - 29.9; OB=30.0+ kg/m 2 ). We used sex-specific ANCOVA to test for linear trend across BMI categories, and determined sex-specific Pearson correlation coefficients of LVM with BMI; both sets of analyses were adjusted for age and systolic blood pressure. Data are summarized as mean ± SD. Results: The Table shows that LVM and LVM/HT increase with greater BMI-category in both sexes. LVM/BSA was similar across BMI-categories, while LVM/TBM decreased. There was no linear trend across BMI-categories for LVM/FFM in either sex. On a continuous basis, LVM and LVM/HT were positively correlated with BMI in both sexes (r=0.20 to 0.35, p<0.001 for all); LVM/BSA was weakly inversely correlated with BMI in women only (r=-0.14, p=0.001) but not men (r=-0.08, p=0.18); LVM/TBM was inversely correlated with BMI (M: r=-0.39, W: r=-0.54; p<0.0001 both); LVM/FFM was not correlated with BMI in either sex (M: r=-0.05, p=0.38, W: r=0.08, p=0.055). Conclusion: LVM as a proportion of TBM (weight) actually decreases with greater BMI, while LVM/FFM is not associated with BMI. Whether LVM is better scaled to FFM vs HT, BSA or TBM for risk stratification purposes remains to be determined.


2003 ◽  
Vol 95 (4) ◽  
pp. 1425-1430 ◽  
Author(s):  
Stephen M. Roth ◽  
E. Jeffrey Metter ◽  
Mechele R. Lee ◽  
Ben F. Hurley ◽  
Robert E. Ferrell

We performed gene screening of the ciliary neurotrophic factor receptor (CNTFR) gene and genotyped three newly identified polymorphisms: C-1703T in the 5′ promoter region, T1069A in intron 5, and C174T in exon 9. We studied the association of these CNTFR variants with muscle strength, mass, and body composition in 465 men and women (20-90 yr) from the Baltimore Longitudinal Study of Aging. Only the C174T variant was significantly associated with muscle-related phenotypes. In the entire cohort, when corrected for age, sex, race, physical activity, and height, homozygotes for the common C allele at C174T (CC) exhibited lower total body mass and body mass index than carriers of the rare T allele, which appeared to be due to significant differences in total nonosseous fat-free mass (FFM) (48.0 ± 0.4 vs. 50.0 ± 0.7 kg; P = 0.011) and lower limb FFM (16.5 ± 0.1 vs. 17.2 ± 0.2 kg; P = 0.002). The CC group also exhibited significantly lower quadriceps concentric and eccentric isokinetic strength values at both 30 and 180°/s than the T allele carriers (all P < 0.04), but these differences were no longer significant after adjustment for lower limb FFM. There were no significant sex-by-genotype interactions. The results indicate that the C174T polymorphism in exon 9 of CNTFR is significantly associated with FFM in men and women, with concomitant differences in muscular strength.


PeerJ ◽  
2018 ◽  
Vol 6 ◽  
pp. e5219
Author(s):  
Wallace A. Silva ◽  
Claudio Andre B. de Lira ◽  
Rodrigo L. Vancini ◽  
Marilia S. Andrade

Background The percentage of sustained maximal oxygen uptake and the running economy are important factors that determine the running success of endurance athletes. Running economy is defined as the oxygen uptake required to run at a given speed and depends on metabolic, cardiorespiratory, biomechanical, neuromuscular, and anthropometric factors. With regard to anthropometric characteristics, total body mass seems to be a crucial factor for the running economy. Moreover, neuromuscular components, especially knee muscular strength and the strength balance ratio, also seem to be critical for the running economy. In addition to knee muscle strength, hip muscle strength is also an important contributor to running performance on level or hilly ground. However, the relationship between running economy and the hip muscles is unknown. Thus the aim of the present study was to verify whether hip flexor and extensor isokinetic peak torque, the isokinetic strength balance ratio, total body mass and fat free mass were associated with running economy in both sexes and to compare sex differences in physical fitness and isokinetic strength characteristics. Methods A total of 24 male (31.0 ± 7.7 years, 176.2 ± 7.3 cm, and 70.4 ± 8.4 kg) and 15 female (31.3 ± 6.7 years, 162.9 ± 3.9 cm, and 56.0 ± 5.3 kg) recreationally-trained endurance runners were recruited. Maximal oxygen uptake, running economy, conventional (concentric flexors-to-concentric extensors) and functional (concentric flexors-to-eccentric extensors) hip isokinetic strength balance ratios, peak torque of the hip flexor and extensor muscles, total body mass, and fat-free mass were measured. Running economy was assessed on two separate days by means of the energy running cost (Ec) using a motorized treadmill at 10.0 and 12.0 km h−1 (3% gradient) and 11.0 and 14.0 km h−1 (1% gradient). Results The functional balance ratio was significantly and negatively associated with Ec at 11.0 (r =  − 0.43, P = 0.04) and 12.0 km h−1 (r =  − 0.65, P = 0.04) when using a 3% gradient in male runners. Considering muscular strength, male runners only showed a significant relationship between Ec (assessed at 12 km h−1 and a 3% gradient) and peak torque for extensor muscle eccentric action (r = 0.72, P = 0.04). For female runners, only peak torque relative to total body mass for extensor muscles (180° s−1) was positively associated with Ec when assessed at 10 km h−1 using a 3% gradient (r = 0.59, P = 0.03). No significant relationships were found between Ec and total body mass or fat-free mass. Discussion Given that the functional balance ratio was associated with a better Ec, coaches and athletes should consider implementing a specific strengthening program for hip flexor muscles to increase the functional ratio.


2021 ◽  
Vol 186 (Supplement_1) ◽  
pp. 424-429
Author(s):  
Narayan Yoganandan ◽  
Tyler F Rooks ◽  
Valeta Carol Chancey ◽  
Frank A Pintar ◽  
Anjishnu Banerjee

ABSTRACT Introduction Current methods for transporting military troops include nonstandard seating orientations, which may result in novel injuries because of different types/directions of loading impact. The objective of this study is to develop pelvic injury risk curves (IRCs) under lateral impacts from human cadaver tests using survival analysis for application to military populations. Methods Published data from lateral impacts applied to whole-body cadaver specimens were analyzed. Forces were treated as response variables. Demographics and body mass index (BMI) were covariates. Injury risk curves were developed for forces without covariates, for males, females, 83 kg body mass, and 25 kg/m2 BMI. Mean and ± 95% confidence interval IRCs, normalized confidence interval sizes at discrete risk levels, and quality indices were obtained for each metric-covariate combination curve. Results Mean age, stature, total body mass, and BMI were 70.1 ± 8.6 years, 1.67 ± 0.1 m, 67.0 ± 14.4 kg, and 23.9 ± 3.97 kg/m2, respectively. For a total body mass of 83 kg, peak forces at 10%, 25%, and 50% probability levels were 5.7 kN, 7.4 kN, and 9.6 kN, respectively. For males, peak forces at the 10%, 25%, and 50% probability levels were 4.8 kN, 6.4 kN, and 8.4 kN, respectively. For females, peak forces at the 10%, 25%, and 50% probability levels were 3.0 kN, 4.0 kN, and 5.2 kN, respectively. Other data and risk curves are given. Conclusions The IRCs developed in this study can be used as injury criteria for the crashworthiness of future generation military vehicles. The introduction of BMI, sex, and total body mass as covariates quantified their contributions. These IRCs can be used with finite element models to assess and predict injury in impact environments to advance Soldier safety. Manikins specific to relevant military anthropometry may be designed and/or evaluated with the present IRCs to assess and mitigate musculoskeletal injuries associated with this posture and impact direction.


2013 ◽  
Vol 25 (2) ◽  
pp. 238-247 ◽  
Author(s):  
Peter A. Hosick ◽  
Robert G. McMurray ◽  
A.C. Hackney ◽  
Claudio L. Battaglini ◽  
Terry P. Combs ◽  
...  

Reports suggest children with high aerobic fitness (VO2max; mL/kg/min) have healthier profiles of TNF-α and IL-6; however, research has not accounted for differences in adiposity between high-fit and low-fit individuals. Thus, this study examined differences in inflammatory markers of obese and normal weight children of different fitness levels, using two different VO2max units: per unit of fat free mass (VO2FFM) or total body mass (VO2kg). Children (n = 124; ages 8–12) were divided into four matched groups; normal weight high-fit (NH), normal weight low-fit (NL), obese high-fit (OH), and obese low-fit (OL). Height, weight, skinfolds, body mass index (BMI), and predicted VO2max were measured and a morning, fasting blood sample taken. IL-6 was elevated in the NL and OL groups compared with the NH group, as well as the OL group compared with the OH group. No differences were found in TNF-α. The relationship between IL-6 or TNF-α and the two units of predicted VO2max did not differ suggesting that either VO2FFM or VO2kg can be used to describe aerobic power when studying inflammation and exercise in youth. The relationship between IL-6 or TNF-α and predicted VO2max, whether expressed per mass or per fat-free mass was similar, suggesting that both can be used to describe aerobic power when studying inflammation and exercise in youth. Given the polar design of this study, this relationship should be confirmed including overweight subjects.


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