Intraspecific variation in avian pectoral muscle mass: constraints on maintaining manoeuvrability with increasing body mass

Shorebirds such as red knots Calidris canutus routinely make migratory flights of 3000 km or more. Previous studies on this species, based on compositional analyses, suggest extensive pectoral muscle hypertrophy in addition to fat storage before take-off. Such hypertrophy could be due to power training and/or be effected by an endogenous circannual rhythm. Red knots of two subspecies with contrasting migration patterns were placed in a climate-controlled aviary (12 h:12 h L:D photoperiod) where exercise was limited. Using ultrasonography, we measured pectoral muscle size as the birds stored fat in preparation for migration. At capture, there were no differences in body mass and pectoral muscle mass between the two subspecies. As they prepared for southward and northward migration, respectively, the tropically wintering subspecies (C. c. canutus) gained 31 g and the temperate wintering subspecies (C. c. islandica) gained 41 g. During this time, pectoral mass increased by 43–44 % of initial mass, representing 39 % (C. c. canutus) and 29 % (C. c. islandica) of the increase in body mass. The gizzard showed atrophy in conjunction with a diet change from molluscs to food pellets. Although we cannot exclude the possibility that the birds' limited movement may still be a prerequisite for pectoral muscle hypertrophy, extensive power training is certainly not a requirement. Muscle hypertrophy in the absence of photoperiod cues suggests the involvement of an endogenous circannual process.

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Evolutionary design of a flexible, seasonally migratory, avian phenotype: why trade gizzard mass against pectoral muscle mass?

Proceedings of The Royal Society B Biological Sciences ◽

10.1098/rspb.2019.0518 ◽

2019 ◽

Vol 286 (1903) ◽

pp. 20190518 ◽

Cited By ~ 2

Author(s):

Kimberley J. Mathot ◽

Eva M. A. Kok ◽

Joseph B. Burant ◽

Anne Dekinga ◽

Petra Manche ◽

...

Keyword(s):

Muscle Mass ◽

Body Mass ◽

Migratory Birds ◽

Common Factor ◽

Pectoral Muscle ◽

Flight Performance ◽

Long Distance ◽

Free Living ◽

Explicit Consideration ◽

Allocation Decisions

Migratory birds undergo impressive body remodelling over the course of an annual cycle. Prior to long-distance flights, red knots (Calidris canutus islandica) reduce gizzard mass while increasing body mass and pectoral muscle mass. Although body mass and pectoral muscle mass are functionally linked via their joint effects on flight performance, gizzard and pectoral muscle mass are thought to be independently regulated. Current hypotheses for observed negative within-individual covariation between gizzard and pectoral muscle mass in free-living knots are based on a common factor (e.g. migration) simultaneously affecting both traits, and/or protein limitation forcing allocation decisions. We used diet manipulations to generate within-individual variation in gizzard mass and test for independence between gizzard and pectoral muscle mass within individuals outside the period of migration and under conditions of high protein availability. Contrary to our prediction, we observed a negative within-individual covariation between gizzard and pectoral muscle mass. We discuss this result as a potential outcome of an evolved mechanism underlying body remodelling associated with migration. Although our proposed mechanism requires empirical testing, this study echoes earlier calls for greater integration of studies of function and mechanism, and in particular, the need for more explicit consideration of the evolution of mechanisms underlying phenotypic design.

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A Cautionary Tale: Cryptic Sexual Size Dimorphism in a Socially Monogamous Passerine

The Auk ◽

10.1093/auk/124.2.515 ◽

2007 ◽

Vol 124 (2) ◽

pp. 515-525 ◽

Cited By ~ 3

Author(s):

Michael T. Murphy

Keyword(s):

Muscle Mass ◽

Body Mass ◽

Sexual Size Dimorphism ◽

Principal Component ◽

Pectoral Muscle ◽

Size Dimorphism ◽

Monogamous Species ◽

Socially Monogamous ◽

Tyrannus Tyrannus ◽

Wing Chord

AbstractAmong socially monogamous birds, standard metrics suggest that males are only ∼5% larger than females. An untested assumption is that, with the exception of reproductive systems, males and females are scaled mirror images of one another. I used external morphological and skeletal data, and information on muscle mass and organ size, to test this assumption in a population of breeding Eastern Kingbirds (Tyrannus tyrannus). Male and female Eastern Kingbirds exhibited no differences in body mass or standard measures of size, except in a longer (∼6%) wing chord and tail in males. However, keel length, a character rarely measured in the field, was 9.7% larger in males. In principal component analysis, overall body size (PC1) failed to differ between the sexes unless keel length was included. Analysis of 16 skeletal characters also showed that only the bones associated with flight were larger in males. However, the most significant differences between the sexes was that lean dry pectoral muscle mass (LDPMM) was nearly 30% greater in males, whereas the alimentary tract was 27.5% heavier in females. Females also carried more fat. In both sexes, LDPMM scaled in a positive allometric manner with body mass (i.e., slope > 1.0), but the significantly higher slope of males suggested especially strong selection for large muscle mass and, presumably, greater power generation during flight. Eastern Kingbirds thus exhibit pronounced cryptic sexual size dimorphism, but it is not clear whether natural or sexual selection is responsible. These data call for a broader perspective for measuring and a re-evaluation of sexual size dimorphism in other socially monogamous species.Un Llamado de Atención: Dimorfismo Críptico en el Tamaño en un Paserino Socialmente Monógamo

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Avian pectoral muscle size rapidly tracks body mass changes during flight, fasting and fuelling

Journal of Experimental Biology ◽

10.1242/jeb.203.5.913 ◽

2000 ◽

Vol 203 (5) ◽

pp. 913-919 ◽

Cited By ~ 14

Author(s):

A. Lindstrom ◽

A. Kvist ◽

T. Piersma ◽

A. Dekinga ◽

M.W. Dietz

Keyword(s):

Muscle Mass ◽

Body Mass ◽

Muscle Thickness ◽

Pectoral Muscle ◽

The Body ◽

Muscle Size ◽

Migratory Flight ◽

Avian Muscle ◽

Require Power ◽

Body Mass Changes

We used ultrasonic imaging to monitor short-term changes in the pectoral muscle size of captive red knots Calidris canutus. Pectoral muscle thickness changed rapidly and consistently in parallel with body mass changes caused by flight, fasting and fuelling. Four knots flew repeatedly for 10 h periods in a wind tunnel. Over this period, pectoral muscle thickness decreased in parallel with the decrease in body mass. The change in pectoral muscle thickness during flight was indistinguishable from that during periods of natural and experimental fasting and fuelling. The body-mass-related variation in pectoral muscle thickness between and within individuals was not related to the amount of flight, indicating that changes in avian muscle do not require power-training as in mammals. Our study suggests that it is possible for birds to consume and replace their flight muscles on a time scale short enough to allow these muscles to be used as part of the energy supply for migratory flight. The adaptive significance of the changes in pectoral muscle mass cannot be explained by reproductive needs since our knots were in the early winter phase of their annual cycle. Instead, pectoral muscle mass changes may reflect (i) the breakdown of protein during heavy exercise and its subsequent restoration, (ii) the regulation of flight capacity to maintain optimal flight performance when body mass varies, or (iii) the need for a particular protein:fat ratio in winter survival stores.

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Effects of a resistance training community programme in older adults

Ageing and Society ◽

10.1017/s0144686x20001786 ◽

2021 ◽

pp. 1-16

Author(s):

Majid Mufaqam Syed-Abdul ◽

Chrissa L. McClellan ◽

Elizabeth J. Parks ◽

Stephen D. Ball

Keyword(s):

Older Adults ◽

Body Mass Index ◽

Resistance Training ◽

Muscle Mass ◽

Body Mass ◽

Fat Mass ◽

Training Programme ◽

Haemoglobin A1c ◽

Community Based ◽

Resistance Training Programme

Abstract Ageing is associated with reduced muscle mass, strength, flexibility and balance, resulting in a poor quality of life (QOL). Past studies have occurred in highly controlled laboratory settings which provide strong support to determine whether similar gains can be made in community programmes. Twenty participants were enrolled in an eight-week community-based resistance training programme (mean age = 61.3 (standard error (SE) = 0.9) years); Body Mass Index = 32.0 (SE = 1.3) kg/m2). All participants completed surveys to assess outcomes associated with QOL. Given the relationship between muscle function and nerve health, nerve conduction studies (NCS) were also conducted in a separate group of participants (mean age = 64.9 (SE = 2.0) years; Body Mass Index = 32.6 (SE = 1.9) kg/m2). This community-based training programme significantly improved QOL measures in older adults (p < 0.001). Although weight loss was not the primary outcome of the study, participants reduced their body weights (p < 0.001), by primarily reducing fat mass (p = 0.007) while maintaining muscle mass. Significant improvements were observed in muscle strength (2.2%), flexibility and balance (3.2–464.2%, p ⩽ 0.05 for all). Improvements were also observed in plasma glucose (p = 0.05), haemoglobin A1C (p = 0.06) and aldolase enzyme levels (p < 0.001). Scores for surveys on memory and sleep improved (p < 0.05). Improved QOL was associated with increased lean mass (r = −0.714, p = 0.002), decreased fat mass (r = −0.702, p = 0.003) and improved flexibility and balance (r = −0.627, p = 0.008). An eight-week, community-based resistance training programme significantly improved QOL in older adults. Influence on the lipid profile and NCS still needs further investigation.

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Methionine restriction plus overload improves skeletal muscle and metabolic health in old mice on a high fat diet

Scientific Reports ◽

10.1038/s41598-021-81037-6 ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Anandini Swaminathan ◽

Andrej Fokin ◽

Tomas Venckūnas ◽

Hans Degens

Keyword(s):

Skeletal Muscle ◽

Glucose Tolerance ◽

Muscle Mass ◽

Body Mass ◽

High Fat Diet ◽

Control Diet ◽

Metabolic Health ◽

High Fat ◽

Methionine Restriction ◽

Old Mice

AbstractMethionine restriction (MR) has been shown to reduce the age-induced inflammation. We examined the effect of MR (0.17% methionine, 10% kCal fat) and MR + high fat diet (HFD) (0.17% methionine, 45% kCal fat) on body mass, food intake, glucose tolerance, resting energy expenditure, hind limb muscle mass, denervation-induced atrophy and overload-induced hypertrophy in young and old mice. In old mice, MR and MR + HFD induced a decrease in body mass. Muscle mass per body mass was lower in old compared to young mice. MR restored some of the HFD-induced reduction in muscle oxidative capacity. The denervation-induced atrophy of the m. gastrocnemius was larger in animals on MR than on a control diet, irrespective of age. Old mice on MR had larger hypertrophy of m. plantaris. Irrespective of age, MR and MR + HFD had better glucose tolerance compared to the other groups. Young and old mice on MR + HFD had a higher resting VO2 per body mass than HFD group. Mice on MR and MR + HFD had a resting respiratory quotient closer to 0.70, irrespective of age, indicating an increased utilization of lipids. In conclusion, MR in combination with resistance training may improve skeletal muscle and metabolic health in old age even in the face of obesity.

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Changes in Muscle Mass after Botulinum Toxin Injection in Children with Spastic Hemiplegic Cerebral Palsy

Toxins ◽

10.3390/toxins13040278 ◽

2021 ◽

Vol 13 (4) ◽

pp. 278

Author(s):

Dongwoo Lee ◽

Jaewon Kim ◽

Ja-Young Oh ◽

Mi-Hyang Han ◽

Da-Ye Kim ◽

...

Keyword(s):

Cerebral Palsy ◽

Botulinum Toxin ◽

Lean Body Mass ◽

Muscle Mass ◽

Body Mass ◽

Botulinum Toxin Injection ◽

Dual Energy ◽

X Ray ◽

Hemiplegic Cerebral Palsy

We aimed to evaluate muscle mass changes after injection of botulinum toxin (BoNT) in children with spastic hemiplegic cerebral palsy (CP). Children aged between 2 and 12 years who were diagnosed with hemiplegic CP with spastic equinus foot were prospectively recruited and administered BoNT in the affected leg. Lean body mass (LBM) of both legs and total limbs was measured by dual-energy X-ray absorptiometry (DXA) preinjection and 4 and 12 weeks after injection. A total of 15 children were enrolled into the study. LBM of both legs and total limbs increased significantly over 12 weeks of growth. The ratio of LBM of the affected leg to total limbs and to the unaffected leg significantly reduced at 4 weeks after injection compared with preinjection but significantly increased at 12 weeks after injection compared with 4 weeks after injection. In conclusion, the muscle mass of the affected leg after BoNT injection in children with hemiplegic spastic CP decreased at 4 weeks after BoNT injection but significantly recovered after 12 weeks after injection.

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Effects of a novel mobile health intervention compared to a multi-component behaviour changing program on body mass index, physical capacities and stress parameters in adolescents with obesity: a randomized controlled trial

BMC Pediatrics ◽

10.1186/s12887-021-02781-2 ◽

2021 ◽

Vol 21 (1) ◽

Author(s):

A. Stasinaki ◽

D. Büchter ◽

C.-H. I. Shih ◽

K. Heldt ◽

S. Güsewell ◽

...

Keyword(s):

Health Care ◽

Body Mass Index ◽

Muscle Mass ◽

Body Mass ◽

Body Fat ◽

Mobile Health ◽

Health Intervention ◽

Randomized Controlled ◽

Physical Capacities ◽

Stress Parameters

Abstract Background Less than 2% of overweight children and adolescents in Switzerland can participate in multi-component behaviour changing interventions (BCI), due to costs and lack of time. Stress often hinders positive health outcomes in youth with obesity. Digital health interventions, with fewer on-site visits, promise health care access in remote regions; however, evidence for their effectiveness is scarce. Methods This randomized controlled not blinded trial (1:1) was conducted in a childhood obesity center in Switzerland. Forty-one youth aged 10–18 years with body mass index (BMI) > P.90 with risk factors or co-morbidities or BMI > P.97 were recruited. During 5.5 months, the PathMate2 group (PM) received daily conversational agent counselling via mobile app, combined with standardized counselling (4 on-site visits). Controls (CON) participated in a BCI (7 on-site visits). We compared the outcomes of both groups after 5.5 (T1) and 12 (T2) months. Primary outcome was reduction in BMI-SDS (BMI standard deviation score: BMI adjusted for age and sex). Secondary outcomes were changes in body fat and muscle mass (bioelectrical impedance analysis), waist-to-height ratio, physical capacities (modified Dordel-Koch-Test), blood pressure and pulse. Additionally, we hypothesized that less stressed children would lose more weight. Thus, children performed biofeedback relaxation exercises while stress parameters (plasma cortisol, stress questionnaires) were evaluated. Results At intervention start median BMI-SDS of all patients (18 PM, 13 CON) was 2.61 (obesity > + 2SD). BMI-SDS decreased significantly in CON at T1, but not at T2, and did not decrease in PM during the study. Muscle mass, strength and agility improved significantly in both groups at T2; only PM reduced significantly their body fat at T1 and T2. Average daily PM app usage rate was 71.5%. Cortisol serum levels decreased significantly after biofeedback but with no association between stress parameters and BMI-SDS. No side effects were observed. Conclusions Equally to BCI, PathMate2 intervention resulted in significant and lasting improvements of physical capacities and body composition, but not in sustained BMI-SDS decrease. This youth-appealing mobile health intervention provides an interesting approach for youth with obesity who have limited access to health care. Biofeedback reduces acute stress and could be an innovative adjunct to usual care.

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Assessment of muscle mass, risk of falls and fear of falling in elderly people with diabetic neuropathy

Fisioterapia em Movimento ◽

10.1590/0103-5150.028.004.ao04 ◽

2015 ◽

Vol 28 (4) ◽

pp. 677-683 ◽

Cited By ~ 1

Author(s):

Hudson Azevedo Pinheiro ◽

Karla Helena Coelho Vilaça ◽

Gustavo de Azevedo Carvalho

Keyword(s):

Diabetic Neuropathy ◽

Lean Body Mass ◽

Muscle Mass ◽

Body Mass ◽

Fear Of Falling ◽

Berg Balance Scale ◽

Elderly Adults ◽

Risk Of Falling ◽

Risk Of Falls ◽

History Of

Abstract Objective : To assess muscle mass, risk of falls and fear of falling in elderly adults with diabetic neuropathy (DNP). Methods : 50 elderly patients with diabetes mellitus (DM) and diabetic neuropathy (NPD) participated in this study. Risk of falling was assessed using the Berg Balance Scale (BBS). Fear of falling was assessed by means of the Falls Efficacy Scale-International (FES-I). Muscle mass was assessed by tetrapolar bioimpedance analysis (BIA) and Janssen's equation. Subjects were divided into two groups: one with a history of falls in the six months before study enrollment (G1) and the other without history of falls (G2). Results : There were statistically significant differences between G1 and G2 regarding lean body mass (p < 0.05), risk of falls as measured by the BBS (p < 0.01), and fear of falling as measured by the FES-I (p < 0.01). In addition, there was a significant correlation between the BBS and BIA (r = 0.45 and p < 0.01), showing that the greater the lean body mass, the lower the risk of falling. Conclusions : We found an association between lean mass, risk of falls and fear of falling in elderly adults with DNP and a history of falls from own height.

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Body and organ mass dynamics during remigial moult in a wing–foot-propelled diving sea duck: the Common Eider (Atlantic) (Somateria mollissima dresseri)

Canadian Journal of Zoology ◽

10.1139/cjz-2015-0062 ◽

2015 ◽

Vol 93 (10) ◽

pp. 755-764 ◽

Cited By ~ 3

Author(s):

A. Viain ◽

M. Guillemette ◽

J.-P.L. Savard

Keyword(s):

Muscle Mass ◽

Body Mass ◽

Flight Muscle ◽

Somateria Mollissima ◽

Dabbling Ducks ◽

Diving Ducks ◽

Common Eiders ◽

Sea Duck ◽

Remigial Moult ◽

Atrophy Of The Heart

Body and organ dynamics, during remigial moult, have been mainly explored on geese, dabbling ducks, and foot-propelled diving ducks, but weakly on sea ducks. This study investigated the internal changes in a wing–foot-propelled sea duck to determine the adaptive strategies implemented. Forty-five male Common Eiders (Atlantic) (Somateria mollissima dresseri Sharpe, 1871), collected in the Gulf of St. Lawrence, were dissected; their body mass, muscle mass, and organ sizes were measured. We tested three hypotheses: (1) S. m. dresseri use a strategic reduction of body mass to reduce the flightlessness duration; (2) organs will exhibit changes consistent with a trade-off between function and maintenance to save and reallocate energy and proteins to feather growth; (3) S. m. dresseri would show lower flight muscle reduction than foot-propelled diving ducks. Somateria mollissima dresseri did not lose body mass, which does not support the first hypothesis. Atrophy of the heart followed by hypertrophy and opposite changes in leg muscle mass and gizzard mass are consistent with the second hypothesis. Flight muscle mass showed lower variations than in other ducks, validating the third hypothesis. We also suggest that the lipid depletion observed early in the moult could be a strategy to reduce foraging effort and minimize the risk of damaging the growing feathers.

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