Growth and physical development of children at apparent risk of sarcopenia.

BACKGROUND: The consequences of sarcopenia on growth have received little attention. We analysed the potential risk resulting from the low lean mass for age expressed through the appendicular lean body mass index (aLBMI) and the ratio aLBM/trunk fat mass (trFM). METHODS: The sample consisted of 580 participants 10-13 yrs evaluated twice in a 12-month interval: height, trFM, total and aLBM, whole-body bone mineral density less head (WBLH BMD), tibia and radius SOS, maturity and handgrip strength were measured. All variables except maturity and BMI were standardised according to sex and age group (Z-score) using the sample as a reference. A high risk of sarcopenia was identified for Z-scores ≤ -1 on aLBMI (Group B) or aLBM/trFM (Group C), while Z-scores > -1 on both markers were considered at low risk for sarcopenia (Group A). The ANCOVA adjusted for maturity was used to compare the three groups. RESULTS: Girls showed a more significant decrease in the total BMC/LBM ratio in Group B and a minor increase in WBLH BMD in Group C (p < 0.050); boys in Group B showed a tendency to gain less height (p = 0.053). CONCLUSION: The high risk of sarcopenia expressed through aLBMI or aLBM/trFM Z-score ≤ -1 compromises bone mineralisation in girls. IMPACT: The findings emphasise the necessity of implementing routine screening protocols for sarcopenia risk within clinical environments and educational institutions. Such screenings should extend beyond merely assessing body mass index to encompass broader body composition variables like lean body mass. By integrating these assessments into routine health evaluations, healthcare professionals and educators can proactively identify at-risk individuals and initiate timely interventions for suboptimal physical growth and development.

Postgraduate education in healthy and active ageing: a systematic scoping review of learning needs, curricula and learning impact.

To inform a new European-based online master's programme in active aging and age-friendly society, a scoping review was performed to identify previously reported learning needs and learning outcomes on this topic. Four electronic databases (PubMed, EBSCO [Academic Search Complete], Scopus, and ASSIA) were systematically searched, along with gray literature. Dual, independent review of an initial 888 studies led to 33 included papers which underwent independent data extraction and reconciliation. Just 18.2% of studies employed a student survey or similar to determine learning needs, with the majority reporting educational intervention objectives, learning outcomes or curriculum content. Main study topics were intergenerational learning (36.4%), age-related design (27.3%), health (21.2%), attitudes toward aging (6.1%), and collaborative learning (6.1%). This review found limited literature on student learning needs in healthy and active aging. Future research should elucidate student- and other stakeholder-determined learning needs, with robust evaluation of post-education skills, attitudes, and practice change.

Learning needs in healthy and active aging according to key stakeholders: a multinational survey.

Healthy and active aging and age-friendly society frameworks attempt to address the well-documented challenges and opportunities of population aging. To meet the needs of an increasingly older society, there is a demand for professionals with appropriate age-related knowledge and skills. To this end, a master's in active aging is in development. This study reports on the consultation with prospective students, employers, older people and academics on the knowledge areas to be included in the course. An anonymous online survey gathered data from stakeholders in Ireland, Slovenia, Austria, Portugal, Finland, and Greece. Participants ranked the importance of 14 broad knowledge areas and linked topics. The influence of participant characteristics on decisions was examined using multivariate regression modeling. Across all stakeholder groups (total sample N = 757), health promotion was most often deemed very important (80%), followed by psychology (73%), and social inclusion and engagement (71%). Potential students from healthcare backgrounds were more interested than others in aging physiology, social aspects, and the physical environment. More western-located European countries overall showed more enthusiasm for the topics presented, additional to regional variations between topics. This learning needs analysis provides multi-stakeholder insights into priorities regarding learning in healthy and active aging and age-friendly society.

Spatial distribution of bed variables, animal welfare indicators, and milk production in a closed compost-bedded pack barn with a negative tunnel ventilation system.

This research aimed to characterize, evaluate and compare the spatial distribution of the leading bed variables, animal welfare indicators, and milk production in a closed compost-bedded pack barn (CBP) with a negative tunnel ventilation system, for summer and winter periods. The study was carried out in a CBP located in the Zona da Mata region, Minas Gerais, Brazil. The geostatistical modeling technique evaluated the variables of temperature, moisture content, and pH (on the surface and depth of 0.20m) across the length of the bed. Bed samples were characterized for carbon (C), nitrogen (N), and C:N ratio. Cows housed in the CBP were assessed for locomotion and hygiene scores and average milk production. To evaluate the thermoregulation of the cows, the respiratory rate (RR) and surface temperature (ST) were measured. Geostatistical analysis showed spatial dependence and the non-uniformity of the spatial distribution of bed variables. The worst levels of bed temperature and moisture were found in the regions close to the evaporative cooling plate, surrounding the feeding alley, and in the region with the highest cow stocking. The C:N ratio, obtained in both climatic seasons of the year, remained outside the recommended range for ideal composting. During the summer and winter, the bed variables' values suggest that the material was below levels for optimal composting; however, the aerated inner layer was biologically active. The high animal density significantly impacted the worsening of the bed moisture content and internal temperature. In general, dairy cows showed adequate hygiene (score of 1 and 2) and locomotion (score of 0 and 1) scores for the two climatic seasons evaluated, indicating good welfare conditions. In relation to RR and ST, the summer period presented less favorable environmental conditions. During winter, the average milk production was 28.1 ± 7.2 kg day-1, and during summer, it was 26.9 ± 6.7 kg day-1.

Adaptation of Proximal Femur to Mechanical Loading in Young Adults: Standard Vs Localized Regions Evaluated by DXA.

Regions of the proximal femur with less adaptive protection by mechanical loading may be at increased risk of structural failure. Since the size and location of these regions diverge from those defined by the dual-energy X-ray absorptiometry manufacturers the purpose of this study was to compare areal bone mineral density (aBMD) of different regions of the proximal femur considering impact loads from physical activity (PA). The participants were 134 young adults divided into 2 groups according to the impact of PA performed in the last 12 mo: high-impact PA and low-impact PA. The aBMD of the proximal femur was assessed by dual-energy X-ray absorptiometry at the standard femoral neck, intertrochanter, and trochanter, and at specific locations of the superolateral femoral neck and intertrochanteric region. The bone-specific physical activity questionnaire was used to estimate the impact load of PA. Comparisons between groups were adjusted for body height and body lean mass. Interaction analysis between sex and PA groups were conducted with analysis of variance. Comparisons of aBMD between bone regions were analyzed separately for men and women with repeated measures analysis of variance. In the high-impact PA group, men benefit more than women at all bone regions, except the aBMD at intertrochanteric region. Analyses of repeated measures did not reveal any significant interaction effect between bone regions (standard vs specific) and PA groups (low vs high-impact). In conclusion, aBMD differences due to mechanical loading were more pronounced in men than in women; the magnitude of the aBMD differences as a result of different levels of PA was similar between standard and localized regions.

Expert's Choice: 2018's Most Exciting Research in the Field of Pediatric Exercise Science.

This commentary highlights 23 noteworthy publications from 2018, selected by leading scientists in pediatric exercise science. These publications have been deemed as significant or exciting in the field as they (a) reveal a new mechanism, (b) highlight a new measurement tool, (c) discuss a new concept or interpretation/application of an existing concept, or (d) describe a new therapeutic approach or clinical tool in youth. In some cases, findings in adults are highlighted, as they may have important implications in youth. The selected publications span the field of pediatric exercise science, specifically focusing on: aerobic exercise and training; neuromuscular physiology, exercise, and training; endocrinology and exercise; resistance training; physical activity and bone strength; growth, maturation, and exercise; physical activity and cognition; childhood obesity, physical activity, and exercise; pulmonary physiology or diseases, exercise, and training; immunology and exercise; cardiovascular physiology and disease; and physical activity, inactivity, and health.

Sedentary Time, Physical Activity, Fitness, and Physical Function in Older Adults: What Best Predicts Sleep Quality?

The aim of this study was to identify the best predictor of sleep quality (SQ) among physical behavior or capacity-related variables, namely physical activity, sedentary time, fitness, and physical function (activities of daily living) of independent elders using a representative sample of Portuguese aged 65 years and older (N = 437). SQ and activities of daily living were evaluated by a questionnaire, sedentary time, and physical activity through accelerometry, and physical fitness by means of the Senior Fitness Test. The logistic regression analysis revealed that activities of daily living measured by the Composite Physical Function was the only explanatory variable discriminating between poor SQ and good SQ. Receiver operating characteristic analysis showed that the best trade-off between sensitivity and specificity to discriminate older adults with poor SQ and good SQ was 20 points in the Composite Physical Function (sensitivity = 57.9%; specificity = 60.9%; area under the curve = 0.600, 95% confidence interval [0.536, 0.665], p = .003). Better physical function seems to be associated with better SQ in independent elders.

Bone Strength and Exercise During Youth-The Year That Was 2017.

The positive effects of physical activity on bone strength are certain. However, researchers have yet to precisely quantify the contribution of specific characteristics of physical activity that affect bone strength in children and adolescents. This commentary highlights 2 noteworthy 2017 publications that addressed osteogenic physical activity dose-response issues. Both papers moved the field forward by providing new insights on physical activity exposures beyond high-impact loading. Koedijk et al's paper was selected because, to the best of our knowledge, it is the first systematic review to solely examine associations between sedentary behavior and indicators of bone strength. The second selected paper, Gabel et al, used novel approaches in accelerometer processing and statistical modeling to separate the osteogenic effects of frequency of short bouts of physical activity from total volume of physical activity. As such, the authors of this paper begin to explore in youth what animal models have shown for some time, that is, optimal bone adaptation requires the correct combination of intensity, frequency, duration, nonrepetitive movement, and rest. Together, these papers signal new and important approaches for the conceptualization, measurement, and interpretation of osteogenic physical activity.

Patterns of accelerometer-derived sedentary time across the lifespan.

We aimed to describe ST and its patterns on a national level. A hip-worn accelerometer (ActiGraph GT1M) was used to collect data during waking hours from 4575 Portuguese' participants from 2007-2009 (2683 females) aged 10-102 years old. Data was presented by sex, in 5-years age intervals, and by adolescents (n=2833), adults (n=1122), and older adults (n=620). Lambda-mu-sigma (LMS) smoothed percentile curves were estimated. Girls, women, and older women spent 61, 57, and 64% of wear time in ST, respectively. In males, ST represented 57, 60, and 62% of wear time respectively for boys, men, and older men. Comparing to other age groups, older adults spent a larger amount of ST in bouts ≥30-min (women: 33%, men: 39% of total ST). The number of breaks/ST hour were: 10.6 in girls, 11.7 in women, and 9.6 in older women. In males, the number of breaks/ST hour were: 11.2, 10.5, and 8.5 for boys, men, and older men. In conclusion, ST was not consistently higher at older ages. Instead, we found that the potential critical moments in which ST may be higher are during adolescence and in the transition from adulthood into older adulthood, which represents critical periods for interventions.

Sexual dimorphism in bone-muscle relationship in young adults.

The purpose of this study was to analyse associations between lean soft tissue (LST), a surrogate of skeletal muscle mass and key fracture-related geometric characteristics of the proximal femur. Moreover, we examined the role that muscle played on the proximal femur geometry in response to physical activity (PA). Participants were 83 young adults. Leg LST (exposure) was assessed by dual energy X-ray absorptiometry (DXA). Proximal femur geometry was derived from a left hip DXA scan. Geometric variables (outcomes) included the femoral neck axis length (FNAL), the femoral neck width (FNW), the neck-shaft angle and FNW|FNAL (an index of robustness). PA was evaluated by accelerometry. Linear regression was used to analyse relationships. Additional exposure variables included body height and mass. In males, leg LST explained 17.4% of variation in FNAL (P < 0.001) and 15% in FNW (P = 0.015). In females, it explained 8.8% of the variance in FNAL (P = 0.020). Associations remained significant in males, but not in females, when vigorous PA was added to the models. These results suggest that public health approaches to promote PA may be particularly important in females since vigorous PA seems to convey advantages in femur geometry and consequently in bone strength.

Pelvis width associated with bone mass distribution at the proximal femur in children 10-11 years old.

Differences in skeletal geometry may generate different patterns of mechanical loading to bone. Impact and muscle loading during physical activity have been shown to influence skeletal geometry. The purpose of this study was to compare geometric measures of the pelvis and proximal femur (PF) of young children and to analyze the contribution and potential interaction of these geometric measures with physical activity on PF bone mass distribution. Participants were 149 girls and 145 boys, aged 10-11 years. Total body and left hip DXA scans were used to derive pelvic and PF geometric measures and PF bone mineral density (BMD) at the femoral neck (FN), trochanter (TR), and intertrochanter (IT). These subregions were used to represent bone mass distribution via three BMD ratios: FN:PF, TR:PF, and IT:PF. Physical activity was objectively measured using accelerometry, and maturity was estimated as the years of distance from peak height velocity. When compared to boys, girls had a wider pelvic diameter and greater interacetabular distances (p < 0.001), lower BMD at FN, TR, and IT (p < 0.05), and higher TR:PF (p < 0.001). After controlling for maturity, body height, and lean body mass, the interacetabular distance in girls explained 21.1 % (ß = 0.713, p < 0.001) in TR:PF and 2.9 % (ß = -0.179, p = 0.031) in the IT:PF. Neck-shaft angle explained 5.6 % (ß = -0.265, p = 0.001) of the IT:PF and 3.1 % (ß = 0.194, p = 0.018) of the FN:PF. In boys, FN axis length explained 2.9 % (ß = 0.195, p = 0.040) of TR:PF. There was no main effect of physical activity or interaction effect with pelvic geometry in explaining BMD differences among the subregions of the PF. Even before sexual dimorphism, girls have a wider pelvis than boys, which accounted for proportionally greater BMD of the TR than other subregions of the PF.

Measurement properties of radial and tibial speed of sound for screening bone fragility in 10- to 12-year-old boys and girls.

The objective of this study was to analyze measurement properties of the radial and tibial speed of sound (SoS) evaluated by quantitative ultrasound (QUS) for screening bone fragility. Bone fragility was defined as low whole body less head bone mineral density (WBLH BMD) measured by DXA (first tertile, 95% CI -1.1 to -0.9) and as past fractures evaluated by questionnaire. The sample included 319 nonobese boys and girls, ages 10-12 yr. All bone variables were standardized. The results revealed concordance coefficient correlations between WBLH BMD and radial and tibial SoS of 0.129 and 0.038, respectively. The regression lines between DXA and QUS variables were different from the identity lines. Cross-classification analysis by Kappa statistic showed that only 34% and 36% of the 113 participants categorized in the first tertile of WBLH BMD were also categorized in the first tertile of tibial and radial SoS, correspondingly. Logistic regression with gender and maturity adjustments demonstrates that radial SoS was the single significant variable in predicting OR for identifying participants with past fractures. In conclusion, the radial QUS revealed itself to be a valuable tool for screening bone fragility in youth of 10-12 yr, despite the absence of agreement with DXA WBLH BMD.

Physical fitness percentiles for Portuguese children and adolescents aged 10-18 years.

This study aimed to produce age- and sex-specific physical fitness reference data for Portuguese youth; to report the prevalence of youth in the healthy zone of physical fitness according to the FITNESSGRAM(®) criteria; to verify the agreement between the Portuguese physical fitness percentiles and the FITNESSGRAM(®) healthy zones. In 2008, 22,048 Portuguese children and adolescents (10-18 years) were evaluated. Physical fitness (curl-ups, push-ups, 20-m shuttle run and modified-back-saver-sit-and-reach tests) was evaluated using the FITNESSGRAM(®) Test Battery 8.0. Smoothed percentile curves were estimated using Cole's LMS method. Boys consistently outperformed girls in every physical fitness test, except for the modified-back-saver-sit-and-reach tests. In both sexes and for all physical fitness tests, higher percentile values were observed at older ages. The 50th percentile of all physical fitness tests had the highest accuracy to discriminate between under healthy zone and healthy zone of the FITNESSGRAM(®). Portuguese schools and physical education teachers may considerer the 50th percentile for age and sex or the FITNESSGRAM(®) criteria for classifying participants in the healthy zone as acceptable cut-offs, above which youth should be considered fit. These reference values can be used as normative data and for baseline values for subsequent surveillance of the physical fitness of Portuguese youth.

Normative functional fitness standards and trends of Portuguese older adults: cross-cultural comparisons.

This cross-sectional study was designed to develop normative functional fitness standards for the Portuguese older adults, to analyze age and gender patterns of decline, to compare the fitness level of Portuguese older adults with that of older adults in other countries, and to evaluate the fitness level of Portuguese older adults relative to recently published criterion fitness standards associated with maintaining physical independence. A sample of 4,712 independent-living older adults, age 65-103 yr, was evaluated using the Senior Fitness Test battery. Age-group normative fitness scores are reported for the 10th, 25th, 50th, 75th, and 90th percentiles. Results indicate that both women and men experience age-related losses in all components of functional fitness, with their rate of decline being greater than that observed in other populations, a trend which may cause Portuguese older adults to be at greater risk for loss of independence in later years. These newly established normative standards make it possible to assess individual fitness level and provide a basis for implementing population-wide health strategies to counteract early loss of independence.

Musculoskeletal fitness: relative handgrip strength and vertical jump power from 10 to 18 years old.

Background: There is an increasing consensus on the relevance of musculoskeletal fitness for health throughout the life cycle, requiring evaluation approaches and description of results capable of characterizing different age groups and body sizes. This study aimed to describe the musculoskeletal fitness of young Portuguese people aged 10-18 through handgrip strength (HGS) and vertical jump power (VJP) and investigate differences between the sexes. Methods: The sample included 736 participants (359 girls recruited from schools. HGS (kg) was assessed using a handheld dynamometer, and VJP (W) was assessed using a force platform; both measurements were standardized for body mass. Results: Higher HGS and VJP were observed in boys than in girls from 13 years old (13 years: p ≤ 0.05; 14-18 years: p ≤ 0.001), with no significant differences before this age. The percentile distributions of HGS and VJP are described for each sex using the lambda, mu, sigma (LMS) method. The pattern of development of these variables as a function of age is presented. Conclusions: Handgrip strength and vertical jump power show differences between the sexes from 13 years of age and similar trajectories to populations in other countries in the same age group.

GIS mapping of agricultural plastic waste in southern Europe.

The escalating use of plastics in agriculture, driven by global population growth and increasing food demand, has concurrently led to a rise in Agricultural Plastic Waste (APW) production. Effective waste management is imperative, prompting this study to address the initial step of management, that is the quantification and localization of waste generated from different production systems in diverse regions. Focused on four Southern European countries (Italy, Spain, Greece, and Portugal) at the regional level, the study uses Geographic Information System (GIS), land use maps, indices tailored to each specific agricultural application and each crop type for plastic waste mapping. Furthermore, after the data was employed, it was validated by relevant stakeholders of the mentioned countries. The study revealed Spain, particularly the Andalusia region, as the highest contributor to APW equal to 324,000 tons per year, while Portugal's Azores region had the lowest estimate equal to 428 tons per year. Significantly, this research stands out as one of the first to comprehensively consider various plastic applications and detailed crop cultivations within the production systems, representing a pioneering effort in addressing plastic waste management in Southern Europe. This can lead further on to the management of waste in this area and the transfer of the scientific proposition to other countries.

Quality of life in sarcopenia measured with the SarQoL questionnaire: A meta-analysis of individual patient data.

Age-related sarcopenia, resulting from a gradual loss in skeletal muscle mass and strength, is pivotal to the increased prevalence of functional limitation among the older adult community. The purpose of this meta-analysis of individual patient data is to investigate the difference in health-related quality of life between sarcopenic individuals and those without the condition using the Sarcopenia Quality of Life (SarQoL) questionnaire. A protocol was published on PROSPERO. Multiple databases and the grey literature were searched until March 2023 for studies reporting quality of life assessed with the SarQoL for patients with and without sarcopenia. Two researchers conducted the systematic review independently. A two-stage meta-analysis was performed. First, crude (mean difference) and adjusted (beta coefficient) effect sizes were calculated within each database; then, a random effect meta-analysis was applied to pool them. Heterogeneity was measured using the Q-test and I2 value. Subgroup analyses were performed to investigate the source of potential heterogeneity. The strength of evidence of this association was assessed using GRADE. From the 413 studies identified, 32 were eventually included, of which 10 were unpublished data studies. Sarcopenic participants displayed significantly reduced health-related quality of life compared with non-sarcopenic individuals (mean difference = -12.32; 95 % CI = [-15.27; -9.37]). The model revealed significant heterogeneity. Subgroup analyses revealed a substantial impact of regions, clinical settings, and diagnostic criteria on the difference in health-related quality of life between sarcopenic and non-sarcopenic individuals. The level of evidence was moderate. This meta-analysis of individual patient data suggested that sarcopenia is associated with lower health-related quality of life measured with SarQoL.

Musculoskeletal Fitness for Identifying Low Physical Function in Older Women.

AIMS: This cross-sectional study aimed to analyze the relevance of musculoskeletal fitness for identifying low physical functioning in community-dwelling older women. METHODS: Sixty-six older women (73.62 ± 8.23 yrs old) performed a musculoskeletal fitness assessment of the upper and lower limbs. A handheld dynamometer was used to evaluate upper-limb muscle strength through a handgrip (HG) test. Lower-limb power and force were assessed from a two-leg countermovement vertical jump (VJ) on a ground reaction force platform. Physical functioning was assessed subjectively using the Composite Physical Function (CPF) questionnaire and objectively by daily step count measured by accelerometry and gait speed/agility assessed by the 8-Foot Up-and-Go (TUG) test. Logistic regressions and ROC curves were carried out to define odds ratios and ideal cutoff values for discriminatory variables. RESULTS: VJ power showed the ability to identify low physical functioning when evaluated through the CPF (14 W/kg, 1011 W), gait speed/agility (15 W/kg, 800 W), or daily accumulated steps (17 W/kg). Considering that VJ power was normalized for body mass, the increase of 1 W/kg corresponds to a decrease of 21%, 19%, or 16% in the chance of low physical functioning when expressed by these variables, respectively. HG strength and VJ force did not show a capacity to identify low physical functioning. CONCLUSIONS: The results suggest that VJ power is the only marker of low physical functioning when considering the three benchmarks: perception of physical ability, capacity for mobility, and daily mobility.

Symptoms of Sarcopenia and Physical Fitness through the Senior Fitness Test.

INTRODUCTION: Physical fitness concerns a set of attributes related to the ability to perform physical activity that may justify the symptoms reported by the elderly in the context of sarcopenia. OBJECTIVE: This study aimed to investigate the relationship between the perception (symptomatology) of physical functioning (what the person thinks they are capable of) and the capacity itself for physical functioning in elderly people in northern Brazil. METHODS: Cross-sectional study that analyzed 312 elderly people (72.6 ± 7.8 years) from the city of Novo Aripuanã, Amazonas, Brazil. Sarcopenia symptomatology was assessed using the SARC-F, a 5-item questionnaire designed for screening sarcopenia in older individuals in five domains: strength, walking aids, difficulty getting up from a chair, difficulty climbing stairs, and falls. Physical fitness was assessed by the Senior Fitness Test (SFT) battery including balance evaluated with the short version of the Fullerton Advanced Balance scale (FAB). RESULTS: ROC curve analysis revealed that the tests with the greatest ability to discriminate participants with significant symptoms for sarcopenia (≥4 points on SARC-F) were arm curl and 6 min walk: the probability of suspected sarcopenia increased exponentially with an arm curl < 11.5 reps for men (se = 71%; sp = 69%; AUC = 0.706, 95% CI: 0.612-0.788; p = 0.013) and women (se = 81%; sp = 51%; AUC = 0.671, 95% CI: 0.601-0.735; p ≤ 0.001) or with a 6-min walk <408.5 m for men (se = 71%; sp = 63%; AUC = 0.720, 95% CI: 0.628-0.690; p = 0.001) and <366.0 m for women (se = 69%; sp = 58%; AUC = 0.692, 95% CI: 0.623-0.755; p = 0.0001). CONCLUSIONS: Physical fitness assessed through the senior fitness test, particularly the 30-s-arm curl test and the 6-min walk test, can discriminate for suspected symptoms of sarcopenia.

Body composition and musculoskeletal fitness: A cluster analysis for the identification of risk phenotypes for pediatric sarcopenia.

BACKGROUND AND AIM: Sarcopenia is primarily a disease in older people characterized by reduced muscle mass and strength. Nevertheless, sarcopenia may, at least partially, have pediatric origins. The study aimed to identify risk phenotypes for sarcopenia in healthy young people using clustering analysis procedures based on body composition and musculoskeletal fitness. METHODS: We conducted a cluster cross-sectional analysis of data from 529 youth aged 10-18 yr. Body composition was assessed using whole-body dual-energy x-ray absorptiometry (DXA), determining: lean body mass index (LBMI, kg/m2), fat body mass index (FBMI, kg/m2), abdominal FBMI (kg/m2), and lean body mass/fat body mass ratio (LBM/FBM); body mass index was also calculated (BMI, kg/m2). Musculoskeletal fitness was assessed using handgrip strength (kg) and vertical jump power (W) tests. Results were presented as absolute values and adjusted by body mass. Plank endurance (s) was also assessed. All variables were sex and age in years standardized (Z-score). LBMI or LBM/FBM ratio ≤ -1 SD were used to identify participants at risk for sarcopenia. Maturity was estimated as the years of distance from the peak height velocity (PHV) age. RESULTS: Using the Z-score means for body composition and musculoskeletal fitness and having LBMI or LBM/FBM ratio as the categorical variables (at risk vs. not at risk), the cluster analyses indicated three homogeneous groups (phenotypes, P): P1, risk body composition and unfit; P2, non-risk body composition and non-fit, and P3, non-risk body composition and fit. With the LBMI as a categorical variable, the ANOVA models showed that the body composition and absolute values of musculoskeletal fitness were in P1 < P2 < P3 and the estimated PHV age of P1 > P3 in both sexes (p < 0.001). Having the LBM/FBM as a categorical variable, higher values of BMI, FBMI, and abdominal FBMI, and lower values of handgrip strength and vertical jump power both adjusted for body mass and plank endurance were observed in P1 than in P2 and/or P3 and the P2 than in the P3 in boys and girls (p < 0.001). CONCLUSIONS: Two risk phenotypes for sarcopenia were identified in apparently healthy young people: I. a low LBMI phenotype with low BMI and II. a low LBM to FBM phenotype with high BMI and FBMI. In both risk phenotypes I and II, musculoskeletal fitness was low. For screening, we suggest using absolute measures of handgrip strength and vertical jump power in phenotype I and body mass adjusted measures of these markers, as well as the plank endurance time in phenotype II.