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Athletes have traditionally been evaluated for body composition by percent fat, percent muscle, and somatotype. Since the late 1980s, dual X-ray absorptiometry (DXA) has offered total and regional body composition of bone mineral content (BMC), lean tissue and fat, but studies involving athletes are rare (11) and have not included regional tissue distribution. In the present study, DXA was used to compare a total of 121 male subjects belonging to 9 different athletic groups and controls. ANOVA showed total tissue percent BMC, lean tissue, and fat were significantly different between the various athletic groups (p <.001). Regional differences in tissue distribution between different athletic groups affect BMC and lean tissue (p <.001), but not fat (p >.05). However, athletes of the leanest groups had different fat distribution to that of nonexercising controls (p <.01). It appears that fat distribution is nonspecific in its response to exercise, while lean and BMC distributions show highly specific adaptations to specific sports. [ABSTRACT FROM AUTHOR]

BACKGROUND: Historically, body image research has relied on generic, whole body outlines, which may not be suited to obese individuals. The development of computer generated, individualized digital images to represent body image may be more effective. METHODS: Sixty volunteers participated, with three categories of subject: lean, obese and lean regular exercisers. Body image was assessed using a digital morphing technique in comparison to two standard paper questionnaires. RESULTS: Using the novel digital morphing tool, obese subjects displayed poorer body awareness (perception) than their lean counterparts (P = 0.03), significantly over-estimating their actual body size. Both genders overestimated body size to a similar degree. For body satisfaction, females wished to be smaller and males to be larger, identifying gender-specific body regions (P < 0.001). Obese subjects showed greatest dissatisfaction (P < 0.001) with body image. There was significant correlation for body image dissatisfaction (P < 0.05) between the digital technique and the questionnaires, which was highest for the figural stimuli questionnaire (r = 0.80, P < 0.001). CONCLUSIONS: This method represents a novel and alternative approach to rating body image perception (IP) and satisfaction in obese subjects, particularly providing data on specific regional areas. Body image dissatisfaction appears to be both due to poor body IP compounded with the desire to be smaller. [ABSTRACT FROM AUTHOR]

Thirty-six adults (24 males, 12 females) were assessed for anthropometric somatotype and body image (perception and satisfaction) by a novel technique using quantitative distortion of a digital still image. Software produced random distortions in nine body regions. The participants manipulated interactive slider controls to adjust each body feature in turn, recreate their perceived image and indicate their desired image. There were no differences in perception between the sexes. However, the ideal-actual differences (i.e. satisfaction) indicated that males desired larger and females smaller features, respectively, in the chest and thighs (P<0.001) and arms and calves (P<0.01). When the male-derived data were partitioned by sport (strength, endurance, team-sport and controls), differences were found in the perceived image size in the chest and rib regions (P<0.01 and P<0.05, respectively). Strength athletes perceived these areas to be smaller and the control group perceived these areas to be larger than the true values. Somatotype analysis indicated that the physique associated with minimal dissatisfaction was 2.0-5.0-3.0 for males and 3.0-2.5-3.0 for females. Cluster analysis, combining anthropometric and satisfaction data, revealed seven distinct subgroups distinguished by particular attributes of physical appearance. We conclude that the method is reliable and that body image includes sex-specific, anthropometric, perceptual and personality-related components. [ABSTRACT FROM AUTHOR]

We describe a 42-year-old woman with histologically confirmed lobomycosis, a cutaneous fungal infection rarely reported outside of Latin America. Our case represents the first published report of imported human lobomycosis in Canada and the fifth in an industrialized country.

Body size is a trait that shapes many aspects of a species' development and evolution. Larger body size is often beneficial in animals, but it can also be associated with life history costs in natural systems. Similarly, miniaturization, the evolution of extremely small adult body size, is found in every major animal group, yet carries its own life history trade-offs. Given that these effects can depend on an animal's environment and life stage and have mainly been studied in species that are already specialized for their size, the life history changes associated with evolutionary shifts in body size warrant additional investigation. Here, we used Drosophila melanogaster populations that had undergone over 400 generations of artificial selection on body size to investigate the changes in life history traits associated with the evolution of extremely large and extremely small body sizes. Populations selected for small body size experienced strong trade-offs in multiple life history traits, including reduced female fecundity and lower juvenile viability. Although we found positively correlated changes in egg size associated with selection for both large and small body size, after adjusting for female body size, females from populations selected for large size had the lowest relative investment per egg and females from populations selected for small size had the highest relative investment per egg. Taken together, our results suggest that egg size may be a key constraint on the evolution of body size in D. melanogaster, providing insight into the broader phenomenon of body size evolution in insects., (© The Author(s) 2024. Published by Oxford University Press on behalf of the European Society of Evolutionary Biology. All rights reserved. For commercial re-use, please contact reprints@oup.com for reprints and translation rights for reprints. All other permissions can be obtained through our RightsLink service via the Permissions link on the article page on our site—for further information please contact journals.permissions@oup.com.)

Sexes often have differing fitness optima, potentially generating intra-locus sexual conflict, as each sex bears a genetic "load" of alleles beneficial to the other sex. One strategy to evaluate conflict in the genome is to artificially select populations discordantly against established sexual dimorphism (SD), reintroducing attenuated conflict. We investigate a long-term artificial selection experiment reversing sexual size dimorphism in Drosophila melanogaster during ~350 generations of sexually discordant selection. We explore morphological and genomic changes to identify loci under selection between the sexes in discordantly and concordantly size-selected treatments. Despite substantial changes to overall size, concordant selection maintained ancestral SD. However, discordant selection altered size dimorphism in a trait-specific manner. We observe multiple possible soft selective sweeps in the genome, with size-related genes showing signs of selection. Patterns of genomic differentiation between the sexes within lineages identified potential sites maintained by sexual conflict. One discordant selected lineage shows a pattern of elevated genomic differentiation between males and females on chromosome 3L, consistent with the maintenance of sexual conflict. Our results suggest visible signs of conflict and differentially segregating alleles between the sexes due to discordant selection., (© The Author(s) 2024. Published by Oxford University Press on behalf of The Society for the Study of Evolution (SSE).)

Transgenic Bt crops are important tools for growers to manage insect pests, but their durability is threatened by the evolution of insect resistance. Implementing a resistance monitoring program is essential to detect and mitigate resistance. For non-high-dose Bt crops, resistance monitoring is challenging, because insect control is not complete, so targeted insects and insect damage will be present even without resistance. Given these challenges, sentinel plots have been used to monitor for insect resistance to non-high-dose crops by assessing changes in the efficacy of a Bt crop over time relative to a non- Bt control. We optimized a sentinel plot resistance monitoring approach for MON 88702 ThryvOn™ cotton, a new non-high-dose Bt product targeting two sucking pest taxa- Lygus ( L. lineolaris and L. hesperus ) and thrips ( Frankliniella fusca and F. occidentalis )-and report here on the thrips monitoring methods and results. Quantifying thrips immatures was the best metric to characterize the impact of the trait, with at least a 40-60% average reduction of thrips immatures on ThryvOn relative to the control cotton at all sites with higher thrips densities. These data can be used within a ThryvOn resistance monitoring program and represent a case study for establishing a resistance monitoring approach for a non-high-dose trait product.

Building, bridge or wind turbine maintenance requires manual dexterity tasks by a specialist rope-access trained workforce via two principal means: harness suspension of individual workers from above, or deployment of a suspended platform or cradle from which workers access the structure to be maintained. Currently no published research compares accuracy and efficiency of simulated maintenance tasks between these modalities. This study investigated manual dexterity task performance of peg placement and shape delineation in seated, standing and suspended environments in 16 healthy controls and 26 professional rope-access trained individuals. Both seated and standing assessments were superior to those suspended, and height of suspension, total mass and years of experience had no influence on the task outcome. These findings suggest that, where feasible, cradle suspension mechanisms which permit standing maintenance are favourable in terms of task efficacy and where feasible, should be considered for deployment in wind energy and other engineering applications., (Copyright © 2020 Elsevier Ltd. All rights reserved.)

Host-plant resistance (HPR) is an important tool for pest management, affording both economic and environmental benefits. The mechanisms of aphid resistance in soybean are not well understood, but likely involve the induction of the jasmonic acid (JA) pathway, and possibly other phytohormone signals involved in plant defense responses. Despite the efficacy of aphid resistance in soybean, virulent aphids have overcome this resistance through mostly unknown mechanisms. Here, we have used metabolomic tools to define the role of plant phytohormones, especially the JA pathway, in regulating interactions between aphid-resistant soybean and virulent aphids. We hypothesized that virulent aphids avoid or suppress the JA pathway to overcome aphid resistance. Our results suggested that aphid-resistant soybean increased accumulation of JA-isoleucine (JA-Ile) only when infested with avirulent aphids; virulent aphids did not cause induction of JA-Ile. Further, applying JA-Ile to aphid-resistant soybean reduced subsequent virulent aphid populations. The concentrations of other phytohormones remained unchanged due to aphid feeding, highlighting the importance of JA-Ile in this interaction. These results increase our knowledge of soybean resistance mechanisms against soybean aphids and contribute to our understanding of aphid virulence mechanisms, which will in turn promote the durability of HPR., (© The Author(s) 2020. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.)

In agricultural systems, crops equipped with host-plant resistance (HPR) have enhanced protection against pests, and are used as a safe and sustainable tool in pest management. In soybean, HPR can control the soybean aphid (Aphis glycines), but certain aphid populations have overcome this resistance (i.e., virulence). The molecular mechanisms underlying aphid virulence to HPR are unknown, but likely involve effector proteins that are secreted by aphids to modulate plant defenses. Another mechanism to facilitate adaptation is through the activity of transposable elements, which can become activated by stress. In this study, we performed RNA sequencing of virulent and avirulent soybean aphids fed susceptible or resistant (Rag1 + Rag2) soybean. Our goal was to better understand the molecular mechanisms underlying soybean aphid virulence. Our data showed that virulent aphids mostly down regulate putative effector genes relative to avirulent aphids, especially when aphids were fed susceptible soybean. Decreased expression of effectors may help evade HPR plant defenses. Virulent aphids also transcriptionally up regulate a diverse set of transposable elements and nearby genes, which is consistent with stress adaptation. Our work demonstrates two mechanisms of pest adaptation to resistance, and identifies effector gene targets for future functional testing., (Copyright © 2020 Elsevier Ltd. All rights reserved.)

Introduction: Fat is a metabolic fuel, but excess body fat is ballast mass, and therefore, many elite athletes reduce body fat to dangerously low levels. Uncompressed subcutaneous adipose tissue (SAT) thickness measured by brightness-mode ultrasound (US) provides an estimate of body fat content., Methods: The accuracy for determining tissue borders is about 0.1-0.2 mm and reliability (experienced measurers) was within ± 1.4 mm (95% limit of agreement, LOA). We present here inter- and intra-measurer scores of three experienced US measurers from each of the centres C1 and C2, and of three novice measurers from each of the centres C3-C5. Each of the five centres measured 16 competitive adult athletes of national or international level, except for one centre where the number was 12. The following sports were included: artistic gymnastics, judo, pentathlon, power lifting, rowing, kayak, soccer, tennis, rugby, basketball, field hockey, water polo, volleyball, American football, triathlon, swimming, cycling, long-distance running, mid-distance running, hurdles, cross-country skiing, snowboarding, and ice hockey. SAT contour was detected semi-automatically: typically, 100 thicknesses of SAT at a given site (i.e., in a given image), with and without fibrous structures, were measured., Results: At SAT thickness sums D I (of eight standardised sites) between 6.0 and 70.0 mm, the LOA of experienced measurers was 1.2 mm, and the intra-class correlation coefficient ICC was 0.998; novice measurers: 3.1 mm and 0.988. Intra-measurer differences were similar. The median D I value of all 39 female participants was 51 mm (11% fibrous structures) compared to 17 mm (18%) in the 37 male participants., Discussion: D I measurement accuracy and precision enables detection of fat mass changes of approximately 0.2 kg. Such reliability has not been reached with any other method. Although females' median body mass index and mass index were lower than those of males, females' median D I was three times higher, and their percentage of fibrous structures was lower. The standardised US method provides a highly accurate and reliable tool for measuring SAT and thus changes in body fat, but training of measurers is important.

Genome size varies widely across organisms yet has not been found to be related to organismal complexity in eukaryotes. While there is no evidence for a relationship with complexity, there is evidence to suggest that other phenotypic characteristics, such as nucleus size and cell-cycle time, are associated with genome size, body size, and development rate. However, what is unknown is how the selection for divergent phenotypic traits may indirectly affect genome size. Drosophila melanogaster were selected for small and large body size for up to 220 generations, while Cochliomyia macellaria were selected for 32 generations for fast and slow development. Size in D. melanogaster significantly changed in terms of both cell-count and genome size in isolines, but only the cell-count changed in lines which were maintained at larger effective population sizes. Larger genome sizes only occurred in a subset of D. melanogaster isolines originated from flies selected for their large body size. Selection for development time did not change average genome size yet decreased the within-population variation in genome size with increasing generations of selection. This decrease in variation and convergence on a similar mean genome size was not in correspondence with phenotypic variation and suggests stabilizing selection on genome size in laboratory conditions.

Our aim was to identify the best anthropometric index associated with waist adiposity. The six weight-status indices included body mass index (BMI), waist-to-hip ratio (WHR), waist-to-height ratio (WHTR), and a new waist-by-height 0.5 ratio (WHT.5R). The association between three waist skinfolds and the six anthropometric indices was conducted using ANCOVA, MANCOVA, allometric modelling and non-linear regression. The strongest predictors of waist adiposity were (1 st ) WHT.5R, (2 nd ) WHTR, (3 rd ) waist circumference (WC), (4 th ) BMI, (5 th ) WHR, and lastly (6 th ) a body shape index ABSI = WC/(BMI 2/3 * height 1/2 ). The allometric and non-linear regression analyses identified the optimal waist-to-height ratio associated with waist adiposity to be (waist * height -0.6 ). The 95% confidence intervals of the height exponents encompassed -0.5 but excluded -1.0 assumed by WHTR. Assuming that excess waist adiposity is an important cardiovascular risk factor, we recommend that the new WHT.5R be used to advise people how to maintain a "healthy" weight.

Sexually antagonistic selection arises when a trait expressed in both sexes (a shared trait) is selected towards different, sex-specific optima. Sex-discordant selection causes different alleles to be favoured in each sex (intralocus sexual conflict). A key parameter responsible for generating this conflict is the intersexual genetic correlation (r MF ), which determines the degree to which heritable genetic variation for the shared trait produces a similar phenotype in both sexes. A strong, positive r MF interferes with adaptation when there is sex-discordant selection. In principle, the r MF can evolve in response to sex-discordant selection: the faster it declines, the faster the resolution of intralocus sexual conflict. Here, we use Drosophila melanogaster to quantify the time scale over which a strong, positive r MF impedes a response to sex-discordant selection for a canonical quantitative trait (body size) with an exceptionally long (250 generations) selection experiment for a complex multicellular organism. We found that, compared with rapid and substantial evolution under sex-concordant selection, a high r MF arrested sex-specific adaptation for 100 generations in females and a minimum of 250 generations in males. Our study demonstrates that a high r MF can lead to a protracted period of adaptive stalemate during the evolution of sexual dimorphism.

This study aimed to assess whether modifying the pitch of a 75° ladder ergometer to vertical had a cardiorespiratory or psychophysical effect on climbing. Nine male participants climbed a ladder ergometer at 75° and subsequently at 90°, adjusted for an equivalent vertical climb rate, completing three climbing bouts at different vertical speeds. One participant dropped out being unable to complete the climb under the 90° condition. Each was monitored for heart rate (HR), V˙O 2 and rating of perceived exertion (RPE). Results showed vertical climbing induced higher V˙O 2 (mean increase 17.3%), higher HR (mean increase 15.8%), and higher RPE at all speeds and that moving from 75°to vertical exacerbates the effect of speed on the cardiorespiratory response to climbing. This may be explained by increased force production required to maintain balance in a vertical climbing position when the body's centre of mass is not above the feet., (Copyright © 2017 Elsevier Ltd. All rights reserved.)

Background: Greater trochanteric fracture/nonunion can be a devastating complication with significant functional impact after total hip arthroplasty, and their fixation remains a challenge because of the significant forces being transmitted as well as the poor bone quality often associated with these fractures. The objective of this study is to investigate the rates of reoperation and trochanteric nonunion using a third-generation cable-plate system at one center., Methods: Thirty-five patients, mean age 72.9 years (range 46-98 years) with 24 women and 11 men, underwent fixation of their fractured greater trochanter using a third-generation cable-plate system. The indications were: periprosthetic fracture (n = 17), complex primary arthroplasty (n = 5), and complex revision arthroplasty (n = 13). Primary outcomes included rates of reoperation and radiographic union., Results: At a mean follow-up of 2.5 years, trochanteric union rate was 62.9% with nonunion rate of 31.4%, and fibrous union in 5.7%. In regard to quality of initial apposition, only 40% achieved a perfect bone on bone reduction. Ten patients (28.6%) had evidence of wire breakage. Five patients (14.3%) required reoperation and removal of the internal fixation because of lateral hip pain., Conclusion: Fixation of the trochanteric fractures remains a challenge with a relatively high reoperation rate. Poor bone quality and capacity to maintain a stable reduction continue to make this complication after total hip arthroplasty a difficult problem to solve., (Copyright © 2017. Published by Elsevier Inc.)

Objectives: In 1984, male UK offshore workers had greater overweight and obesity prevalence and fat content than the general population. Since then, body weight has increased by 19%, but, without accompanying anthropometric measures, their size increase, current obesity, and fatness prevalence remain unknown. This study therefore aimed to acquire contemporary anthropometric data, profile changes since the original survey, and assess current obesity prevalence in the male offshore workforce., Methods: A total of 588 men, recruited via quota sampling to match the workforce weight profile, underwent stature, weight, and 3D photonic scanning measurements from which anatomical girths were extracted, enabling computation of body mass index (BMI), total fat, and visceral adipose tissue (VAT)., Results: On average, UK male offshore workers are now 8.1 y older, 3.1 cm taller, 13.9 kg heavier, and have greater girths than in 1984, which are >97% attributable to increased weight, and <3% to age difference. Mean BMI increased significantly from 24.9 to 28.1 kg/m 2 and of the contemporary sample, 18% have healthy weight, 52% are overweight, and 30% obese, representing an increase in overweight and obesity prevalence by 6% and 24%, respectively. Waist cutoffs identify 39% of the contemporary sample as healthy, 27% at increased health risk, and 34% at high risk., Conclusions: UK offshore workers today have higher BMI than Scottish men, although some muscular individuals may be misclassified by BMI. Girth data, particularly at the waist, where dimensional increase was greatest, together with predictions of total and visceral fatness, suggest less favorable health status in others., (© 2017 Wiley Periodicals, Inc.)

'Climb assist' claims to reduce strain when climbing ladders; however, no research has yet substantiated this. The purpose of this study was to assess the physiological and psychophysical effects of climb assist on 30 m ladder climbing at a minimum acceptable speed. Eight participants (six male and two female) climbed a 30 m ladder at 24 rungs per minute with and without climb assist, and were monitored for heart rate (HR), [Formula: see text]O 2 and rate of perceived exertion (RPE). All three variables decreased significantly (p < 0.05) with climb assist with [Formula: see text]O 2 decreasing by 22.5%, HR by 14.8% and RPE decreasing by a mean of 2.3 units on the 10-point Borg scale. When descending the ladder [Formula: see text]O 2 decreased by a mean of 42% compared to that ascending. At the minimal acceptable climbing speed climb assist decreases the physiological strain on climbers, as demonstrated by reduced [Formula: see text]O 2 , HR and perceived exertion. Practitioner Summary: 'Climb assist' systems claim to reduce strain when climbing, however; no research has yet been published to substantiate this. A crossover study compared [Formula: see text]O 2 , HR and RPE at a minimal acceptable climbing speed with and without climb assist. Climb assist significantly reduced all variables confirming it reduces strain when climbing.

Objectives: Applying geometric similarity predictions of body dimensions to specific occupational groups has the potential to reveal useful ergonomic and health implications. This study assessed a representative sample of the male UK offshore workforce, and examined how body dimensions from sites typifying musculoskeletal development or fat accumulation, differed from predicted values., Methods: A cross sectional sample was obtained across seven weight categories using quota sampling, to match the wider workforce. In total, 588 UK offshore workers, 84 from each of seven weight categories, were measured for stature, mass and underwent 3D body scans which yielded 22 dimensional measurements. Each measurement was modeled using a body-mass power law (adjusting for age), to derive its exponent, which was compared against that predicted from geometric similarity., Results: Mass scaled to stature 1.73 (CI: 1.44-2.02). Arm and leg volume increased by mass 0.8 , and torso volume increased by mass 1.1 in contrast to mass 1.0 predicted by geometric similarity. Neck girth increased by mass 0.33 as expected, while torso girth and depth dimensions increased by mass 0.53-0.72 , all substantially greater than assumed by geometric similarity., Conclusions: After controlling for age, offshore workers experience spectacular "super-centralization" of body shape, with greatest gains in abdominal depth and girth dimensions in areas of fat accumulation, and relative dimensional loss in limbs. These findings are consistent with the antecedents of sarcopenic obesity, and should be flagged as a health concern for this workforce, and for future targeted research and lifestyle interventions., (© 2016 Wiley Periodicals, Inc.)

Background: Precise and accurate field methods for body composition analyses in athletes are needed urgently., Aim: Standardisation of a novel ultrasound (US) technique for accurate and reliable measurement of subcutaneous adipose tissue (SAT)., Methods: Three observers captured US images of uncompressed SAT in 12 athletes and applied a semiautomatic evaluation algorithm for multiple SAT measurements., Results: Eight new sites are recommended: upper abdomen, lower abdomen, erector spinae, distal triceps, brachioradialis, lateral thigh, front thigh, medial calf. Obtainable accuracy was 0.2 mm (18 MHz probe; speed of sound: 1450 m/s). Reliability of SAT thickness sums (N=36): R(2)=0.998, SEE=0.55 mm, ICC (95% CI) 0.998 (0.994 to 0.999); observer differences from their mean: 95% of the SAT thickness sums were within ± 1 mm (sums of SAT thicknesses ranged from 10 to 50 mm). Embedded fibrous tissues were also measured., Conclusions: A minimum of eight sites is suggested to accommodate inter-individual differences in SAT patterning. All sites overlie muscle with a clearly visible fascia, which eases the acquisition of clear images and the marking of these sites takes only a few minutes. This US method reaches the fundamental accuracy and precision limits for SAT measurements given by tissue plasticity and furrowed borders, provided the measurers are trained appropriately., (Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/)

The effective population size (N(e)) is a fundamental parameter in population genetics that influences the rate of loss of genetic diversity. Sexual selection has the potential to reduce N(e) by causing the sex-specific distributions of individuals that successfully reproduce to diverge. To empirically estimate the effect of sexual selection on N(e), we obtained fitness distributions for males and females from an outbred, laboratory-adapted population of Drosophila melanogaster. We observed strong sexual selection in this population (the variance in male reproductive success was ∼14 times higher than that for females), but found that sexual selection had only a modest effect on N(e), which was 75% of the census size. This occurs because the substantial random offspring mortality in this population diminishes the effects of sexual selection on N(e), a result that necessarily applies to other high fecundity species. The inclusion of this random offspring mortality creates a scaling effect that reduces the variance/mean ratios for male and female reproductive success and causes them to converge. Our results demonstrate that measuring reproductive success without considering offspring mortality can underestimate Ne and overestimate the genetic consequences of sexual selection. Similarly, comparing genetic diversity among different genomic components may fail to detect strong sexual selection., (© 2015 The Author(s). Evolution © 2015 The Society for the Study of Evolution.)

Dual energy X-ray absorptiometry (DXA) is rapidly becoming more accessible and popular as a technique to monitor body composition, especially in athletic populations. Although studies in sedentary populations have investigated the validity of DXA assessment of body composition, few studies have examined the issues of reliability in athletic populations and most studies which involve DXA measurements of body composition provide little information on their scanning protocols. This review presents a summary of the sources of error and variability in the measurement of body composition by DXA, and develops a theoretical model of best practice to standardize the conduct and analysis of a DXA scan. Components of this protocol include standardization of subject presentation (subjects rested, overnight-fasted and in minimal clothing) and positioning on the scanning bed (centrally aligned in a standard position using custom-made positioning aids) as well as manipulation of the automatic segmentation of regional areas of the scan results. Body composition assessment implemented with such protocol ensures a high level of precision, while still being practical in an athletic setting. This ensures that any small changes in body composition are confidently detected and correctly interpreted. The reporting requirements for studies involving DXA scans of body composition include details of the DXA machine and software, subject presentation and positioning protocols, and analysis protocols.

It was the aim of the present study to expand on previous correlation analyses that have attempted to identify factors that influence performance of jumping, sprinting, and changing direction. This was achieved by using a regression approach to obtain linear models that combined anthropometric, strength, and other biomechanical variables. Thirty rugby union players participated in the study (age: 24.2 ± 3.9 years; stature: 181.2 ± 6.6 cm; mass: 94.2 ± 11.1 kg). The athletes' ability to sprint, jump, and change direction was assessed using a 30-m sprint, vertical jump, and 505 agility test, respectively. Regression variables were collected during maximum strength tests (1 repetition maximum [1RM] deadlift and squat) and performance of fast velocity resistance exercises (deadlift and jump squat) using submaximum loads (10-70% 1RM). Force, velocity, power, and rate of force development (RFD) values were measured during fast velocity exercises with the greatest values produced across loads selected for further analysis. Anthropometric data, including lengths, widths, and girths were collected using a 3-dimensional body scanner. Potential regression variables were first identified using correlation analyses. Suitable variables were then regressed using a best subsets approach. Three factor models generally provided the most appropriate balance between explained variance and model complexity. Adjusted R values of 0.86, 0.82, and 0.67 were obtained for sprint, jump, and change of direction performance, respectively. Anthropometric measurements did not feature in any of the top models because of their strong association with body mass. For each performance measure, variance was best explained by relative maximum strength. Improvements in models were then obtained by including velocity and power values for jumping and sprinting performance, and by including RFD values for change of direction performance.

Over 12 weeks, supervised physical activity (PA) interventions have demonstrated improvements in morphological and health parameters, whereas community walking programmes have not. The present study piloted a self-guided programme for promoting PA and reducing sedentary behaviour in overweight individuals and measured its effect on a range of health outcomes. Six male and 16 female sedentary adults aged 48.5 ± 5.5 years with body mass index (BMI) 33.4 ± 6.3 kg m(-2) were assessed for anthropometric variables, blood pressure, functional capacity, well-being and fatigue. After an exercise consultation, participants pursued their own activity and monitored PA points weekly. At baseline, mid-point and 12 weeks, eight participants wore activity monitors, and all participants undertook a 5-day food diary to monitor dietary intake. In 17 completers, mass, BMI, sit-to-stand, physical and general fatigue had improved by 6 weeks. By 12 weeks, waist, sagittal abdominal diameter (SAD), diastolic blood pressure, well-being and most fatigue dimensions had also improved. Throughout the intervention, PA was stable, energy intake and lying time decreased and standing time increased; thus, changes in both energy intake and expenditure explain the health-related outcomes. Observed changes in function, fatigue and quality of life are consistent with visceral fat loss and can occur at levels of weight loss which may not be considered clinically significant.

A focus on low body weight and body fat content, combined with regulations in some weight-sensitive sports, are considered risk factors for extreme dieting, eating disorders (EDs) and related health consequences among athletes. At present there are, from a health perspective, no generally accepted optimum values for body weight or percentage of fat mass in different sports and there is no 'gold standard' method for body composition assessment in athletes. On the basis of health considerations as well as performance, medical support teams should know how to approach elite athletes who seek to achieve an unrealistic body composition and how to prevent restrictive eating practices from developing into an ED. In addition, these teams must know when to raise the alarm and how to advice athletes who are affected by extreme dieting or clinical EDs. However, there is no consensus on when athletes struggling with extreme dieting or EDs should be referred for specialist medical treatment or removed from competition. Based on the present review, we conclude that there is a need for (1) sport-specific and gender-specific preventive programmes, (2) criteria for raising alarm and 'does not start' (DNS) for athletes with EDs and (3) modifications to the regulations in some sports. Further, the key areas for research identified include the development of standard methods for body composition assessment in elite athletes; screening measures for EDs among athletes; development and testing of prevention programmes; investigating the short and long-term effects of extreme dieting; and EDs on health and performance.

Background: Very low body mass, extreme mass changes, and extremely low per cent body fat are becoming increasingly common in many sports, but sufficiently reliable and accurate field methods for body composition assessment in athletes are missing., Methods: Nineteen female athletes were investigated (mean (SD) age: 19.5 (± 3.3) years; body mass: 59.6 (± 7.6) kg; height: 1.674 (± 0.056) m; BMI: 21.3 (± 2.3) kg/m(2)). Three observers applied diagnostic B-mode-ultrasound (US) combined with the evaluation software for subcutaneous adipose tissue measurements at eight ISAK sites (International Society for the Advancement of Kinanthrometry). Regression and reliability analyses are presented., Results: US measurements and evaluation of subcutaneous adipose tissue (SAT) thicknesses (including fibrous structures: D(included); n=378) resulted in an SE of estimate SEE=0.60 mm, R(2)=0.98 (p<0.001), limit of agreement LOA=1.18, ICC=0.968 (0.957-0.977). Similar values were found for D(excluded): SEE=0.68 mm, R(2)=0.97 (p<0.001). D(included) at individual ISAK sites: at biceps, R(2)=0.87 and intraclass-correlation coefficient ICC=0.811 were lowest and SEE=0.79 mm was highest. Values at all other sites ranged from R(2): 0.94-0.99, SEE: 0.42-0.65 mm, and ICC: 0.917-0.985. Interobserver coefficients ranged from 0.92 to 0.99, except for biceps (0.74, 0.83 and 0.87). Evaluations of 20 randomly selected US images by three observers (D(included)) resulted in: SEE=0.15 mm, R(2)=0.998(p<0.001), ICC=0.997 (0.993, 0999)., Conclusions: Subject to optimal choice of sites and certain standardisations, US can offer a highly reliable field method for measurement of uncompressed thickness of the SAT. High accuracy and high reliability of measurement, as obtained with this US approach, are essential for protection of the athlete's health and also for optimising performance.

Background: Successful performers in weight-sensitive sports are characterised by low body mass (BM) and fat content. This often requires chronic energy restriction and acute weight loss practices., Aim: To evaluate current use of body composition (BC) assessment methods and identify problems and solutions with current BC approaches., Methods: A 40-item survey was developed, including demographic and content questions related to BC assessment. The survey was electronically distributed among international sporting organisations. Frequencies and χ(2) analyses were computed., Results: 216 responses were received, from 33 countries, representing various institutions, sports and competitive levels. Of the sample, 86% of respondents currently assess BC, most frequently using skinfolds (International Society for the Advancement of Kinanthropometry (ISAK): 50%; non-ISAK, conventional: 40%; both: 28%), dual energy X-ray absorptiometry (38%), bioelectrical impedance (29%), air displacement plethysmography (17%) and hydrostatic weighing (10%). Of those using skinfolds, more at the international level used ISAK, whereas conventional approaches were more reported at regional/national level (p=0.006). The sport dietitian/nutritionist (57%) and physiologist/sports scientist (54%) were most frequently the professionals assessing BC, followed by MDs and athletic trainers, with some reporting coaches (5%). 36% of 116 respondents assessed hydration status and more (64%) did so at international than regional/national level (36%, p=0.028). Of 125 participants answering the question of whether they thought that BC assessment raised problems, 69% said 'yes', with most providing ideas for solutions., Conclusions: Results show high use of BC assessment but also a lack of standardisation and widespread perception of problems related to BM and BC in sport. Future work should emphasise standardisation with appropriate training opportunities and more research on BC and performance.

Background: Relationships between sitting height (SH) and leg length (LL) in adults are almost always studied in terms of ratios such as the Cormic Index (CI), SH/stature, rather than as primary variables. They are affected by genetics and childhood nutrition., Aim: To characterize these relationships and test whether the CI is ideal as an index of relative LL., Subjects and Methods: Regression and reduced major axis (RMA) equations were calculated for 1653 men and women of European descent. For other population groups the RMA parameters were calculated from published means and standard deviations of SH and LL., Results: Linear and 'allometric' (power) equations fit the data equally well. For people of European origin the RMA equations for men and women do not differ significantly. Corresponding equations for other populations differ in line with published CIs., Conclusions: The linear equations suggest that LL tends to vary in proportion to SH minus a quantity similar to head height. A new index of relative LL may therefore be preferable to the CI for some research purposes to reflect this, but there is otherwise no strong reason to abandon the use of the CI.

Waist girth is recognised as a better predictor of obesity, particularly abdominal obesity, compared to other measures. Although several protocols for waist girth exist, arm position is either ignored, or not specified in unambiguous terms. Therefore, the purpose of this study was to determine if arm position influenced anthropometric waist girth measurement. Waist girth was measured in 92 adults (19 males, 73 females) with arms relaxed, abducted, horizontal, folded across the chest (three variations) and raised vertically. Duplicate measures, in all positions, were recorded by a single International Society for the Advancement of Kinanthropometry (ISAK)-trained technician to a precision of 0.2% technical error of measurement (TEM). Arm position had a significant effect (P < 0.001) on waist girth. Male participants had greater waist girth than females (P < 0.001) and the waist girth differences across the varying arm positions exhibited a significant position-by-gender interaction (P < 0.001). The arm position-by-body mass index (BMI) category interaction was also significant (P = 0.016) with greater differences observed at higher BMI. These findings suggest caution in comparing results of different studies where arm position is not specified and indicate that the arm position corresponding to the ISAK protocol has the lowest error and is therefore recommended.

Objectives: These were to examine the relationship between leg cross-sectional areas (CSAs) and leg length while making allowance for other factors, such as fatness and the load on the legs., Methods: Body mass, stature, and sitting height were directly measured and volumes and leg CSAs were obtained by 3D scanning for 155 men and 162 women. Leg CSAs were regressed simultaneously on upper body mass and leg length., Results: With allowance made for positive correlations with upper body mass, leg CSAs showed a negative correlation with leg length (P = 0.00006-0.027)., Conclusion: There is a negative correlation between leg lengths and CSAs that is largely obscured by other influences., (Copyright © 2012 Wiley Periodicals, Inc.)

The purpose of this study was to compare the biomechanics of the traditional squat with 2 popular exercise variations commonly referred to as the powerlifting squat and box squat. Twelve male powerlifters performed the exercises with 30, 50, and 70% of their measured 1 repetition maximum (1RM), with instruction to lift the loads as fast as possible. Inverse dynamics and spatial tracking of the external resistance were used to quantify biomechanical variables. A range of significant kinematic and kinetic differences (p < 0.05) emerged between the exercises. The traditional squat was performed with a narrow stance, whereas the powerlifting squat and box squat were performed with similar wide stances (48.3 ± 3.8, 89.6 ± 4.9, 92.1 ± 5.1 cm, respectively). During the eccentric phase of the traditional squat, the knee traveled past the toes resulting in anterior displacement of the system center of mass (COM). In contrast, during the powerlifting squat and box squat, a more vertical shin position was maintained, resulting in posterior displacements of the system COM. These differences in linear displacements had a significant effect (p < 0.05) on a number of peak joint moments, with the greatest effects measured at the spine and ankle. For both joints, the largest peak moment was produced during the traditional squat, followed by the powerlifting squat, then box squat. Significant differences (p < 0.05) were also noted at the hip joint where the largest moment in all 3 planes were produced during the powerlifting squat. Coaches and athletes should be aware of the biomechanical differences between the squatting variations and select according to the kinematic and kinetic profile that best match the training goals.

We piloted three-dimensional (3D) body scanning in eating disorder (ED) patients. Assessments of 22 ED patients (including nine anorexia nervosa (AN) patients, 12 bulimia nervosa (BN) patients, and one patient with eating disorder not otherwise specified) and 22 matched controls are presented. Volunteers underwent visual screening, two-dimensional (2D) digital photography to assess perception and dissatisfaction (via computerized image distortion), and adjunctive 3D full-body scanning. Patients and controls perceived themselves as bigger than their true shape (except in the chest region for controls and anorexia patients). All participants wished to be smaller across all body regions. Patients had poorer veridical perception and greater dissatisfaction than controls. Perception was generally poorer and dissatisfaction greater in bulimia compared with anorexia patients. 3D-volume:2D-area relationships showed that anorexia cases had least tissue on the torso and most on the arms and legs relative to frontal area. The engagement of patients with the scanning process suggests a validation study is viable. This would enable mental constructs of body image to be aligned with segmental volume of body areas, overcoming limitations, and errors associated with 2D instruments restricted to frontal (coronal) shapes. These novel data could inform the design of clinical trials in adjunctive treatments for eating disorders., (© 2011 The British Psychological Society.)

One of the most popular exercises for developing lower-body muscular power is the weighted vertical jump. The present study sought to examine the effect of altering the position of the external load on the kinematics and kinetics of the movement. Twenty-nine resistance-trained rugby union athletes performed maximal effort jumps with 0, 20, 40, and 60% of their squat 1 repetition maximum (1RM) with the load positioned (a) on the posterior aspect of the shoulder using a straight barbell and (b) at arms' length using a hexagonal barbell. Kinematic and kinetic variables were calculated through integration of the vertical ground reaction force data using a forward dynamics approach. Performance of the hexagonal barbell jump resulted in significantly (p < 0.05) greater values for jump height, peak force, peak power, and peak rate of force development compared with the straight barbell jump. Significantly (p < 0.05) greater peak power was produced during the unloaded jump compared with all trials where the external load was positioned on the shoulder. In contrast, significantly (p < 0.05) greater peak power was produced when using the hexagonal barbell combined with a load of 20% 1RM compared with all other conditions investigated. The results suggest that weighted vertical jumps should be performed with the external load positioned at arms' length rather than on the shoulder when attempting to improve lower-body muscular performance.

Quantifying human body composition has played an important role in monitoring all athlete performance and training regimens, but especially so in gravitational, weight class and aesthetic sports wherein the tissue composition of the body profoundly affects performance or adjudication. Over the past century, a myriad of techniques and equations have been proposed, but all have some inherent problems, whether in measurement methodology or in the assumptions they make. To date, there is no universally applicable criterion or 'gold standard' methodology for body composition assessment. Having considered issues of accuracy, repeatability and utility, the multi-component model might be employed as a performance or selection criterion, provided the selected model accounts for variability in the density of fat-free mass in its computation. However, when profiling change in interventions, single methods whose raw data are surrogates for body composition (with the notable exception of the body mass index) remain useful.

Males and females usually invest asymmetrically in offspring. In species lacking parental care, females influence offspring in many ways, while males only contribute genetic material via their sperm. For this reason, maternal effects have long been considered an important source of phenotypic variation, while paternal effects have been presumed to be absent or negligible. The recent surge of studies showing trans-generational epigenetic effects questions this assumption, and indicates that paternal effects may be far more important than previously appreciated. Here, we test for sex-linked paternal effects in Drosophila melanogaster on a life-history trait, and find substantial support for both X- and Y-linked effects.

Sexual coevolution occurs when changes in the phenotype of one sex select for changes in the other sex. We can identify the "footprint" of this coevolution by mating males and females from different populations and testing for a male-female genotype interaction for a trait associated with male (or female) performance. Here we mated male Drosophila melanogaster from five different continents with females from their own and different continents to test for a male-female interaction for mating speed, a pre-copulatory trait, and female reproductive investment, a post-copulatory trait. We found a strong male-female interaction for mating speed, consistent with previous studies using different populations, suggesting that the potential for sexual coevolution for this trait is present in this species. In contrast, we did not detect a male-female interaction for female reproductive investment. Although a male-female interaction for mating speed is compatible with the hypothesis of ongoing sexual coevolution, the nature of our experimental design is unable to exclude alternate explanations. Thus, the evolutionary mechanisms promoting male-female genotype interactions for pre-copulatory mating traits in D. melanogaster warrant further investigation.

The purpose of this study was to investigate whether the deadlift could be effectively incorporated with explosive resistance training (ERT) and to investigate whether the inclusion of chains enhanced the suitability of the deadlift for ERT. Twenty-three resistance trained athletes performed the deadlift with 30, 50, and 70% 1-repetition maximum (1RM) loads at submaximal velocity, maximal velocity (MAX), and MAX with the inclusion of 2 chain loads equal to 20 or 40% of the subjects' 1RM. All trials were performed on force platforms with markers attached to the barbell to calculate velocity and acceleration using a motion capture system. Significant increases in force, velocity, power, rate of force development, and length of the acceleration phase (p < 0.05) were obtained when repetition velocity increased from submaximal to maximal. During MAX repetitions with a constant resistance, the mean length of the acceleration phase ranged from 73.2 (±7.2%) to 84.9 (±12.2%) of the overall movement. Compared to using a constant resistance, the inclusion of chains enabled greater force to be maintained to the end of the concentric action and significantly increased peak force and impulse (p < 0.05), while concurrently decreasing velocity, power, and rate of force development (p < 0.05). The effects of chains were influenced by the magnitude of the chain and barbell resistance, with greater increases and decreases in mechanical variables obtained when heavier chain and barbell loads were used. The results of the investigation suggest that the deadlift can be incorporated effectively in ERT programs. Coaches and athletes should be aware that the inclusion of heavy chains may have both positive and negative effects on kinematics and kinetics of an exercise.

In many species, males can influence the amount of resources their mates invest in reproduction. Two favoured hypotheses for this observation are that females assess male quality during courtship or copulation and alter their investment in offspring accordingly, or that males manipulate females to invest heavily in offspring produced soon after mating. Here, we examined whether there is genetic variation for males to influence female short-term reproductive investment in Drosophila melanogaster, a species with strong sexual selection and substantial sexual conflict. We measured the fecundity and egg size of females mated to males from multiple isofemale lines collected from populations around the globe. Although these traits were not strongly influenced by the male's population of origin, we found that 22 per cent of the variation in female short-term reproductive investment was attributable to the genotype of her mate. This is the first direct evidence that male D. melanogaster vary genetically in their proximate influence on female fecundity, egg size and overall reproductive investment.