Estimated Body Mass Research Articles

Body mass estimation from knee breadth, with application to early hominins.

The estimation of living body mass from skeletal dimensions is an important component of many studies of early hominins and more recent human archaeological remains. Most previous investigations have concentrated on weight-bearing elements of the lower limb, in particular the femoral head. In this study, we develop new body mass estimation equations derived from measurements of the knee in a modern sample of known body mass, and use them to estimate body mass in 11 fossil hominin specimens (including Au. africanus, Au. afarensis, and early Homo). The reference sample consisted of 100 living subjects who participated in the Baltimore Longitudinal Study of Aging. Mediolateral breadth measurements were taken from radiographs of the knee, and regressed against recorded body weight to generate body mass estimation equations. Knee dimensions were generally found to be good predictors of body mass in the modern human sample, with median absolute percent prediction errors of 7 to 9% (comparable to or better than previously reported equations derived from the femoral head). Taxon-average estimated body masses were 46.1 kg for Au. afarensis, 38.4 kg for Au. africanus, and 53.6 kg for early Homo. Estimates for early Homo were similar to or smaller than those generated previously from the femoral head. Estimates for australopiths, however, were larger than those generated from femoral head equations. This result is consistent with other evidence that the femoral head was relatively unloaded in australopiths compared with Homo, possibly due to subtle differences in gait. Am J Phys Anthropol 158:198-208, 2015. © 2015 Wiley Periodicals, Inc.

Body mass estimates of hominin fossils and the evolution of human body size

Body size directly influences an animal's place in the natural world, including its energy requirements, home range size, relative brain size, locomotion, diet, life history, and behavior. Thus, an understanding of the biology of extinct organisms, including species in our own lineage, requires accurate estimates of body size. Since the last major review of hominin body size based on postcranial morphology over 20 years ago, new fossils have been discovered, species attributions have been clarified, and methods improved.Here, we present the most comprehensive and thoroughly vetted set of individual fossil hominin body mass predictions to date, and estimation equations based on a large (n = 220) sample of modern humans of known body masses. We also present species averages based exclusively on fossils with reliable taxonomic attributions, estimates of species averages by sex, and a metric for levels of sexual dimorphism. Finally, we identify individual traits that appear to be the most reliable for mass estimation for each fossil species, for use when only one measurement is available for a fossil.Our results show that many early hominins were generally smaller-bodied than previously thought, an outcome likely due to larger estimates in previous studies resulting from the use of large-bodied modern human reference samples. Current evidence indicates that modern human-like large size first appeared by at least 3–3.5 Ma in some Australopithecus afarensis individuals. Our results challenge an evolutionary model arguing that body size increased from Australopithecus to early Homo. Instead, we show that there is no reliable evidence that the body size of non-erectus early Homo differed from that of australopiths, and confirm that Homo erectus evolved larger average body size than earlier hominins.

Estimating body mass from skeletal material: new predictive equations and methodological insights from analyses of a known-mass sample of humans

Estimating body mass from skeletal material is a key task for many biological anthropologists. As a result, several sets of regression equations have been derived for cranial and postcranial material. The equations have been applied to a wide range of specimens, but several factors suggest they may not be as reliable as generally assumed. Specifically, since many of the equations were derived from small reference samples using proxies for key variables and/or mean data, the nature of the relationship between the skeletal variables and body mass has often not been adequately demonstrated. In addition, few of the equations have been validated on known samples, making their accuracy and precision uncertain. Lastly, because no study has used cranial and postcranial material from the same individuals, the two approaches have never been systematically compared. The present study responded to these issues by deriving new regression equations from cranial and postcranial material using a large sample of modern humans of known-mass and associated skeletal variables measured from CT data. The equations were then tested on an independent sample, also of known mass. The results show that the newly derived equations estimate mass more accurately than existing equations for most variables. However, improvements were modest and accuracy rates remained relatively low. In addition, variables that had previously been argued to be ideal predictors were not the most accurate, and the current criteria used to assess equations did not ensure reliability. Overall, the results suggest that body mass estimates must be used cautiously and that further research is required.

Downsizing a giant: re-evaluating Dreadnoughtus body mass.

Estimates of body mass often represent the founding assumption on which biomechanical and macroevolutionary hypotheses are based. Recently, a scaling equation was applied to a newly discovered titanosaurian sauropod dinosaur (Dreadnoughtus), yielding a 59 300 kg body mass estimate for this animal. Herein, we use a modelling approach to examine the plausibility of this mass estimate for Dreadnoughtus. We find that 59 300 kg for Dreadnoughtus is highly implausible and demonstrate that masses above 40 000 kg require high body densities and expansions of soft tissue volume outside the skeleton several times greater than found in living quadrupedal mammals. Similar results from a small sample of other archosaurs suggests that lower-end mass estimates derived from scaling equations are most plausible for Dreadnoughtus, based on existing volumetric and density data from extant animals. Although volumetric models appear to more tightly constrain dinosaur body mass, there remains a clear need to further support these models with more exhaustive data from living animals. The relative and absolute discrepancies in mass predictions between volumetric models and scaling equations also indicate a need to systematically compare predictions across a wide size and taxonomic range to better inform studies of dinosaur body size.

Estimating body mass from postcranial variables: an evaluation of current equations using a large known-mass sample of modern humans

Many inferences in palaeoanthropology and bioarchaeology rely on estimates of body mass from skeletal material. Body mass estimation is also becoming an area of interest for forensic anthropologists. The most common approach to estimating body mass from the skeleton involves measurements of the postcranium, and a number of equations have been developed for femoral head size and stature plus bi-iliac breadth. These equations have become standard in biological anthropology, but they have rarely been tested on individuals of known mass. In addition, the effects of several assumptions involved in the application of the equations have not been rigorously investigated. Accordingly, this study employed CT scans from a sample of 253 adult modern humans of known body mass to test the accuracy of the most widely used postcranial body mass estimation equations. The results were then used to evaluate several claims concerning the performance of the equations relative to one another. Most of the equations that were tested met the criteria for acceptance as reliable estimators with the male and the combined-sex samples. However, females were not estimated as reliably. In addition, the equations did not always perform consistently or as expected. Overall, our results suggest that estimating body mass with the postcranial equations that are currently available requires more caution than is usually exercised.

A new species of Gaylordia Paula Couto (Mammalia, Metatheria) from Itaboraí, Brazil

We describe a new metatherian of the genus Gaylordia Paula Couto, from the early Eocene Itaborai Basin, Brazil. This new species (estimated body mass ~60-90.9 g) is based on lower and upper dentition elements and is characterized by a more plesiomorphic dental morphology with respect to G. macrocynodonta Paula Couto (with a larger body mass, estimated in ~74-103 g for large individuals or males). The species G. doelloi Marshall, represented by small individuals or females, is regarded a junior synonym of G. macrocynodonta. A phylogenetic analysis as well as details of the occlusal surface of its upper and lower molars suggests that Gaylordia is closely related to the Pucadelphyidae, a non-marsupial “ameridelphian” group previously recorded at the early Paleocene locality of Tiupampa, Bolivia.

Multivariate indices as estimates of dry body weight for comparative study of body size in Lepidoptera

Comparative studies on the size of adult Lepidoptera (moths and butterflies) frequently rely on single linear estimates of body size, namely of forewing length or wingspan. As the shape of the wings of these insects - in fact, of all body parts - differs from one taxon to another, such estimates of body mass may not be adequate for comparisons across a wide taxonomic range. Using the length and width of the forewing, thorax and abdomen, as well as the wing area of 375 species and their correlations with dry body weight, several composite indices were determined that might be used in different circumstances. As the coefficients of determination from the multivariate regression models were rather high (R 2 >0.96), the results are believed to be reliable. A critical re-evaluation of the results indicates that important varia- tions in the regression slopes described here would be expected, if at all, only from species with unusual body shapes. Incidentally, the bivariate relationships are in agreement with former comparative work on Lepidoptera and other terrestrial insects in that the relationship between body weight and single linear measurements follows a slightly negatively allometric trend, implying comparatively lighter bodies at the largest body sizes and relatively heavier ones at the shortest body sizes.

A combined morphometric analysis of foot form and its association with sex, stature, and body mass.

Morphometric analysis of footprints is a classic means for orthopedic diagnosis. In forensics and physical anthropology, it is commonly used for the estimation of stature and body mass. We studied individual variation and sexual dimorphism of foot dimensions and footprint shape by a combination of classic foot measurements and geometric morphometric methods. Left and right feet of 134 healthy adult males and females were scanned twice with a 3D optical laser scanner, and stature as well as body mass were recorded. Foot length and width were measured on the 3D scans. The 2D footprints were extracted as the plantar-most 2 mm of the 3D scans and measured with 85 landmarks and semilandmarks. Both foot size and footprint shape are sexually dimorphic and relate to stature and body mass. While dimorphism in foot length largely results from dimorphism in stature, dimorphism in footprint shape partly owes to the dimorphism in BMI. Stature could be estimated well based on foot length (R(2) = 0.76), whereas body mass was more closely related to foot width (R(2) = 0.62). Sex could be estimated correctly for 95% of the individuals based on a combination of foot width and length. Geometric morphometrics proved to be an effective tool for the detailed analysis of footprint shape. However, for the estimation of stature, body mass, and sex, shape variables did not considerably improve estimates based on foot length and width.

A Predictive Shift: Juvenile Obesity's Effect on Established Predictive Models of Body Mass Estimation

Ruff (2007) and Robbins et al. (2010) have developed widely used predictive equations to estimate juvenile body mass (BM) using skeletal measurements of the lower limb. However, the samples used to develop these equations were comprised of healthy weighted individuals and it is unknown whether the formulae accurately predict BM of overweight individuals. To assess this concern, the aforementioned BM estimation equations were tested using a modern sample with documented BM. Radiographs and de-identified patient information (age, weight, sex and medical necessity) of 50 individuals (1-18 years old) were obtained from two independent clinics in Knoxville, TN and Lewisburg, WV. Using this information, the sample was divided in 2 groups: healthy weight and obese. All radiographs included the femur and tibia in their entirety. Osirix DICOM viewer was used to obtain measurements of the femoral head and metaphyses. The BM estimations for both the healthy weighted and obese groups using the predictive equations based on the distal femur metaphysis maximum (Ruff, 2007) were not significant. However, BM estimates derived from equations using the femoral head among obese individuals differed significantly different compared to actual body mass. These findings suggest that some of the predictive equations do not adequately account for overweight individuals and that factors such as the added pressure of being overweight during development potentially influence femoral head morphology.

Masticatory Biomechanics of the Largest Fossil Rodent

The largest known fossil rodent is Josephoartigasia monesi, from the Pliocene of Uruguay, with an estimated body mass of around 1000 kg. Previous work has revealed that the incisors would be able to withstand much greater forces than are estimated to have been produced by the masticatory muscles. Here, finite element analysis was used predict stress distributions across the cranium and maximum bite force at the incisors and the cheek teeth. A sensitivity study was conducted in which the muscle forces and orientations were sequentially altered, to account for the uncertainty in the estimated muscle forces. J. monesi was predicted to have a bite force of 1389 N at the incisors, rising to 4165 N at the third molar. The sensitivity analyses showed that varying muscle force magnitudes by 20% and muscle orientations by 10° led to a maximum change in bite force estimate of 30-33% at all teeth. Predicted stress patterns during biting were only minimally affected by changes to muscle forces and orientations, but revealed a considerable safety factor in cranial strength. These results, combined with previous work, suggest that J. monesi may have been using its incisors activities other than feeding, such as digging or defence, much as an elephant uses its tusks.

Characterization of symptoms and edema distribution in premenstrual syndrome.

BackgroundPremenstrual syndrome is a group of symptoms linked to the menstrual cycle, and edema is among these symptoms. Physiotherapy is often sought by many patients for the treatment of edema; however, for an adequate prescription of physiotherapeutic procedures, the distribution of edema throughout the body has yet to be characterized.ObjectiveTo determine the most frequent symptoms and body regions that present with edema in women during the premenstrual period.Subjects and methodsSixty women with a mean age of 24.6±4.7 years were evaluated during their premenstrual (between days 21 and 28) and menstrual period (between days 1 and 3), and the collected data included body mass, height, biotype (body-fat distribution), face, breast, limb-circumference measurements, and limb-volume estimate, and an adapted version of the Premenstrual Symptoms Screening Tool was used. Statistical analysis was performed using Student’s t-test and the test for equality of two proportions (P≤0.05).ResultsPremenstrual syndrome was identified in 91.7% of the women, and the most frequent symptoms were irritability (73.33%) and physical symptoms, including swelling (65%), and anxiety (58.3%). Edema was detected in the following areas: facial, epigastric, mammary, umbilical, and pubic, the mid-third of the arms, distal forearm, in both thighs and in the mid-third of the legs determined by circumference measurements, and in both upper and lower limbs, according to the estimated volume.ConclusionIn this study population, the most frequent symptoms were irritability, physical symptoms, and anxiety, with distribution of edema in the face, breast, abdomen, pubic area, distal upper limb, and proximal lower limb.

Body mass estimates of an exceptionally complete Stegosaurus (Ornithischia: Thyreophora): comparing volumetric and linear bivariate mass estimation methods.

Body mass is a key biological variable, but difficult to assess from fossils. Various techniques exist for estimating body mass from skeletal parameters, but few studies have compared outputs from different methods. Here, we apply several mass estimation methods to an exceptionally complete skeleton of the dinosaur Stegosaurus. Applying a volumetric convex-hulling technique to a digital model of Stegosaurus, we estimate a mass of 1560 kg (95% prediction interval 1082–2256 kg) for this individual. By contrast, bivariate equations based on limb dimensions predict values between 2355 and 3751 kg and require implausible amounts of soft tissue and/or high body densities. When corrected for ontogenetic scaling, however, volumetric and linear equations are brought into close agreement. Our results raise concerns regarding the application of predictive equations to extinct taxa with no living analogues in terms of overall morphology and highlight the sensitivity of bivariate predictive equations to the ontogenetic status of the specimen. We emphasize the significance of rare, complete fossil skeletons in validating widely applied mass estimation equations based on incomplete skeletal material and stress the importance of accurately determining specimen age prior to further analyses.

Hilarcotherium castanedaii, gen. et sp. nov., a new Miocene astrapothere (Mammalia, Astrapotheriidae) from the Upper Magdalena Valley, Colombia

ABSTRACTAstrapotheria is an order of extinct South American herbivores recorded throughout the continent, from the late Paleocene to middle Miocene. Here we describe Hilarcotherium castanedaii, gen. et sp. nov., an Uruguaytheriinae astrapothere from sediments of La Victoria Formation (middle Miocene) in the Tolima Department, Upper Magdalena Valley, Colombia. H. castanedaii, represented by a partial skull, mandible, and some postcranial remains, is characterized by (1) unique dental formula, with 0/3i, 1/1c, 1/1p, and 3/3 m; and (2) lower canines with subtriangular transverse section at the base. Hilarcotherium differs from the equatorial Uruguaytheriinae genera Xenastrapotherium and Granastrapotherium in (1) having three lower incisors; (2) the diagonal implantation of the lower canines; (3) lower molars with lingual cingulid; (4) the presence of the hypocone in the third upper molar; and (5) the presence of an anterolingual pocket in the fourth upper premolar. Our phylogenetic analysis supports the monophyly of the subfamilies Astrapotheriinae and Uruguaytheriinae. Within the latter, we confirm the monophyly of the neotropical clade (Hilarcotherium, Xenastrapotherium, and Granastrapotherium). H. castanedaii shows some plesiomorphic features such as the aforementioned presence of the i3 and the developed hypocone in the last upper molar. Its estimated body mass (1303 kg) is intermediate among Astrapotheriidae.http://zoobank.org/urn:lsid:zoobank.org:pub:82377B38-8B39-4D71-9117-FD17CB329238SUPPLEMENTAL DATA—Supplemental materials are available for this article for free at www.tandfonline.com/UJVP

Multivariate analysis of neognath skeletal measurements: implications for body mass estimation in Mesozoic birds

The abundant fossils of avian stem taxa unearthed during the last years make it necessary to review and improve the models for estimating body mass used in palaeoecological studies. In this article, single and multiple regression functions based on osteological measurements were obtained from a large data set of extant flying birds for estimating the body mass of 42 Mesozoic specimens from stem taxa Archaeopterygidae, Jeholornithidae, Sapeornithidae, Confuciusornithidae, and Enantiornithes, and basal members of Ornithuromorpha. Traditionally, body mass has been estimated in fossil vertebrates using univariate scaling functions. In contrast, multiple regression functions have been used less frequently. Both predictive methods can be affected by different sources of error from statistics, phylogenetic relationships, ecological adaptations, and bone preservation; however, although some studies have addressed these biases, few have tested them within the context of a single data set. In our data set, we find that the models with greater predictive strength and applicability for new specimens, especially for stem taxa, are those derived from multiple regression analyses. For this reason, we suggest that multiple regression analyses may provide improved predictive strength for stem group specimens. Moreover, the methodology used for selecting variables allowed us to obtain specific sets of predictors for each fossil stem group that presumably minimized the variation resulting from historical contingency (i.e. differences in skeletal morphology arising from phylogeny), locomotor adaptations, and diagenetic compaction. The loss of generalizability in the multiple regression models resulting from collinearity effects was negligible on the body mass estimates derived from our data set. Therefore, the body mass values obtained for Mesozoic specimens are accurate and can be used in future studies in a number of palaeobiological and evolutionary aspects of extinct birds, particularly the first stages of avian flight.

Predicting bite force and cranial biomechanics in the largest fossil rodent using finite element analysis.

Josephoartigasia monesi, from the Pliocene of Uruguay, is the largest known fossil rodent, with an estimated body mass of 1000 kg. In this study, finite element analysis was used to estimate the maximum bite force that J. monesi could generate at the incisors and the cheek teeth. Owing to uncertainty in the model inputs, a sensitivity study was conducted in which the muscle forces and orientations were sequentially altered. This enabled conclusions to be drawn on the function of some of the masticatory muscles. It was found that J. monesi had a bite of 1389 N at the incisors, rising to 4165 N at the third molar. Varying muscle forces by 20% and orientations by 10° around the medio-lateral aspect led to an error in bite force of under 35% at each tooth. Predicted stresses across the skull were only minimally affected by changes to muscle forces and orientations, but revealed a reasonable safety factor in the strength of the skull. These results, combined with previous work, lead us to speculate that J. monesi was behaving in an elephant-like manner, using its incisors like tusks, and processing tough vegetation with large bite forces at the cheek teeth.

The weight of fossil leporids and ochotonids: body mass estimation models for the order Lagomorpha

AbstractLagomorphs are widespread around the world, but little is known about the biology and ecology of their fossil ancestors. In this case, knowing the body mass of these extinct species is of principal interest because it is correlated with physiological, morphological and life history attributes. Moreover, insular fossil rabbits, hares and pikas, which became spectacular giants with huge weights and dramatic shifts in their life histories, encourage curiosity in the research world. Our principal aim is to create allometric models between skeletal parameters and body weights with extant species of the order Lagomorpha (both ochotonids and leporids). These regressions can then be applied to the fossil register to estimate the body mass of the extinct lagomorphs. The models are satisfactory in all cases, although weaker relationships were obtained when we analyzed dental parameters. Multiple models have slightly better results than bivariate ones, but their use is limited to complete bones or skeletons. These body mass estimation models were tested in three different fossil lagomorphs: Prolagus apricenicus, Prolagus cf. calpensis and Nuralagus rex. In all three cases, the results from dental variables were discarded due to the fact that these species may not follow the allometric relationship between teeth and body mass of standard lagomorphs. Other variables, such as the proximal anteroposterior diameter of the humerus in N. rex, were also removed for their implications in fossorial lifestyle. We ultimately estimated a weight of around 600 g for P. apricenicus, 300 g for P. cf. calpensis and 8000 g for N. rex. Differences in extrinsic mortality explain the important differences in body masses between the two Prolagus species. The results of N. rex cannot be compared with the giant Prolagus due to phylogenetic differences.

Nutritional status in children with cancer: Before, during and after therapy.

Malnutrition is prevalent in children with cancer at diagnosis, especially in low- and middle-income countries (LMIC) where the great majority of children live. It is associated with an added burden of morbidity and mortality. Answers were sought to the best measure of nutritional status in LMIC, the impact of anti-neoplastic therapy, effective interventions to achieve normal nutritional status and the impact of these on clinical outcomes. Arm anthropometry offers reasonable estimates of fat mass and lean body mass that are both impacted adversely by treatment. Nutritional supplementation, including the use of simple local resources, is beneficial and can improve survival. Long-term survivors may continue to exhibit perturbed nutritional status. The prevalence and severity of malnutrition in children with cancer in LMIC demand attention. Opportunities exist to conduct studies in India to examine the effects of nutritional interventions, including on the overall well-being of survivors.

Intelligent physical exercise training intervention at the workplace for health promotion among office workers: A randomized controlled trial

Background: Health promotion at the workplace can be effective by introducing physical exercise training for preventing lifestyle diseases such as cardiovascular, metabolic, and musculoskeletal disorders. The present aim was to assess the effects of individually tailored intelligent physical exercise programs for office workers on cardiovascular health risk indicators. Methods: The study was a randomized controlled trial among office workers allocated to either a training (N=194) or a control group (N=195). The intervention lasted one year, and the training group trained onehour high intensity dynamic exercise everyweek during working hours and were recommended 30min of moderate intensity physical activity 6 days a week during leisure time. Before and after the intervention participants completed a health check including a standardized submaximal bicycle test with heart rate monitoring for indirect estimate of maximal oxygen uptake (VO2max), body mass, BMI, blood pressure (BP), and blood profile. Data from the first health check were used to individually tailor the intelligent physical exercise training. Trial registration was in ClinicalTrials.gov, number: NCT01366950. Results: At baseline, the training group had a (mean± SD) VO2max of 3.3±0.9 l/min and a fitness level (VO2max per body mass) of 36±11 (ml/min/kg), systolic/diastolic BP 124±17/82±11mmHg, blood glucose 5.3±1mmol/l, and blood cholesterol 5.1±0.9mmol/l. An intention-to-treat analysis showed a significant 5% increase in VO2max and fitness level in the training group compared with the control group. Furthermore, within the training group a significant decrease occurred in systolic/diastolic BP of 3.4/2.8mmHg, and blood glucose of 0.2mmol/l. No intervention effect was found on BMI, blood cholesterol, and triglycerides. In a per protocol analysis among employees in the training group with an adherence ≥70% (N=102) compared to the control group showed a significant 10% increase in VO2max and fitness level. Further, within the high adherence group a decrease in systolic/diastolic BP of 4.4/3.3mmHg, and blood cholesterol of 0.2mmol/l was seen. Discussion:High intensity intelligent physical exercise training combined with recommendations of moderate intensity physical activity significantly increased VO2max and fitness level. The magnitude of increase implied a decrease in cardiovascular health risk based on findings in larger epidemiological studies. Of note is that this increase was larger among those with the highest adherence. Within the training group deceases in systolic BP and blood glucose/cholesterol additionally indicateddecreasedhealth risks. In all this study was effective in decreasing health risk indicators among office workers.

Endocranial and Inner Ear Morphology of Vintana Sertichi (Mammalia, Gondwanatheria) from the Late Cretaceous of Madagascar

ABSTRACTWe present the first digital reconstruction of the endocranial cavity and endosseous labyrinth of the Late Cretaceous gondwanatherian mammal Vintana sertichi from the Maevarano Formation of Madagascar. The Malagasy specimen is exceptionally well preserved and represents the only described cranium known for Gondwanatheria, an enigmatic clade from the Late Cretaceous and Paleogene of Gondwana. The endocranial cast of Vintana is relatively small for an animal of its estimated body mass. Its encephalization quotient is 0.28–0.56 for a range of body mass estimates, which is similar to that of basal mammaliaforms. The olfactory bulbs are very large, occupying over 14% of the endocranial volume. The cerebral hemispheres are only slightly expanded, more similar to the condition in Morganucodon than to that in multituberculates and monotremes. Unlike the condition in other Mesozoic mammaliaforms, the endocast is greatly flexed at the circular fissure. The osseous labyrinth displays a mixture of derived and primitive features. The cochlear canal is only slightly curved and short compared with that of extant therians. The ratio between total cochlear canal length and maximum cranial length is smaller than in basal mammaliaforms and approximates that of non-mammaliaform cynodonts. By contrast, the presence of both primary and secondary osseous laminae, the tractus foraminosus, and Rosenthal's canal represent derived characteristics of the mammalian inner ear typical of cladotherians. A modern innervation of the cochlea has either evolved independently in Vintana and cladotherians or was already present in the last common ancestor of both clades.SUPPLEMENTAL DATA—Supplemental materials are available for this article for free at www.tandfonline.com/UJVP

Anthropometrics, Body Composition, And Aerobic Fitness in Norwegian Home Guard Personnel

The Norwegian Home Guard (HG) consists of soldiers and officers who primarily live a civilian life but are typically called in for military training a few days per year. Although full-time soldiers and officers are monitored annually on physical fitness, no such assessments are performed on regular HG personnel. Data on physical fitness of similar forces from other nations are also scarce. Thus, the main aim of this study was to collect reference data on physical fitness in HG personnel. A total of 799 male soldiers and officers from the regular and the rapid reaction HG force participated in this study. Between 13 and 19% of the subjects were obese, according to measured body mass index, waist circumference and estimations of body fat. The mean (95% confidence interval) estimated peak oxygen uptake from the 20-m shuttle run test was 50.1 (49.7-50.6) mL·kg·minute. Personnel from the rapid reaction force had a more favorable body composition compared with the regular HG personnel, whereas no differences were found for peak oxygen uptake. The physical demands on HG personnel are not well defined, but we believe that the majority of Norwegian HG soldiers and officers have a sufficient aerobic fitness level to fulfill their planned HG tasks. The gathered data can be used by military leaders to review the ability of the HG to perform expected military tasks, to serve as a future reference material for secular changes in HG fitness level, and for comparison purposes among similar international reserve forces.