Are body circumferences able to predict strength, muscle mass and bone characteristics in obesity? A preliminary study in women

Measurement of body circumferences (BCs) is widely used as an anthropometric tool to assess body composition and health risk in obese individuals. In this preliminary work we evaluated the association of several BCs with Dual-energy X-ray Absorptiometry (DXA)-measured lean mass as well as leg press test scores with an aim at exploring the potential of BCs as predictor of body composition and muscle strength. A total of 34 female participants aged 47.3\ub17.6 y who were obese (BMI, 30.4-43.7 kg/m2) were recruited. The upper arm (relaxed), wrist, chest, waist, hip, thigh, and calf circumferences were measured. The skinfold-corrected muscle (including bone) circumferences at the arm, thigh, and calf site were also calculated. Lean mass components were measured by DXA with a Hologic QDR Explorer scanner according to the manufacturer's procedures. Lower limbs strength was assessed with the 1-Repetition Maximum leg press. Bivariate association between variables was assessed with the Spearman's correlation coefficient after the Benjamini and Hochberg False Discovery Rate procedure. Predictive equations were developed using stepwise multiple regression analysis. Several statistically significant correlations (Benjamini and Hochberg corrected P [Pc] < 0.05) were present between BCs and DXA-measured body composition variables, and leg press test scores with special regard to the chest, arm, waist, and hip circumferences. Multiple regression analysis yielded statistically significant predictive models (Pc < 0.05 for all; adjusted R2 ranging 0.123 - 0.504; standard error of the estimate ranging 4.0% - 11% of the mean measured value) for all body composition as well as leg press outcomes. The current findings show that BCs represent a simple, suitable anthropometric measurement with a potential to predict several lean mass components as well as lower limbs strength in obese females. The proposed predictors need to be validated in a larger sample of participants and in obese males

Evaluation of the flow resistance in mobile bed vegetated rivers

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Different amount of training affects body composition and performance in High-Intensity Functional Training participants

The effects of High-Intensity Functional Training (HIFT) on body composition and the relationship of the latter with performance are not well defined. In this work we investigated, by means of Dual-energy X-ray Absorptiometry, the relative proportions of fat-, lean soft tissue-, and mineral mass in CrossFit\uae (CF, a popular mode of HIFT) participants (n = 24; age, 28.2 \ub1 3.39 y; BMI, 25.3 \ub1 2.04 kg/m2) with at least 1 year of CF training experience and weekly amount of training > 10 h/w (n = 13; Higher Training, HT) or < 10 h/w (n = 11; Lower Training, LT) as well as age- matched and BMI-matched physically active controls (CHT, CLT). Performance was assessed in the "Fran" workout. Data were analyzed by one-way or repeated measures ANOVA where needed. Association between variables was assessed with the Pearson's correlation coefficient r. Partial correlation was used where needed. Results showed that HT performed better than LT in the "Fran" (P < 0.001) and they had higher whole-body bone mineral density (P = 0.026) and higher lean soft mass (P = 0.002), and borderline lower percent fat mass (P = 0.050). The main difference between CF participants (HT, LT) and their respective controls (CHT, CLT) was a lower adiposity in the former. In CF participants, performance positively correlated with appendicular lean soft tissue mass (P = 0.030). It can be concluded that, in CF participants, a higher amount of weekly training improves most notably lean body mass and increases performance in association with increased skeletal muscle mass. CF participation is especially effective in reducing fat mass vs. age- and BMI-matched physically active controls

The role of age, sex, anthropometry, and body composition as determinants of physical fitness in nonobese children aged 6\u201312

PURPOSE: The determinants of physical fitness in children have been given limited attention. In particular, the relative role of chronological age, sex, anthropometry, and body composition in physical fitness of children has been barely investigated. This cross-sectional study investigated determinants of physical fitness using a set of predictive variables including, in addition to chronological age and sex, a large panel of anthropometric measurements as well as body composition. The study was carried out in a convenience sample of children aged 6\u201312 participating in a summer camp. METHODS: One-hundred-ninety-three children (128 males) fulfilled all requirements and entered analysis. Health-related physical fitness components (speed, muscular power and balance) were explored by means of field tests, namely the 30-m dash test for running speed, the standing long jump and the seated chest pass test for lower limbs and upper body muscular power, respectively, and the flamingo balance test for static balance. Determinants of physical fitness were investigated by regression analysis using chronological age, sex, anthropometry, and body composition in a hierarchical approach. To minimize the expected effect of collinearity in predictor variables, an original statistical approach using Random Forests analysis was adopted. RESULTS: Age predicted 45.2%, 43.6%, 35.6% and 25.6%; and sex 9.5%, 10.7%, 6.3% and 2.0% of variance in the 30-m dash, seated chest pass, standing long jump, and flamingo balance test, respectively. Anthropometry and body composition explained a limited or no percentage of variance. The adjusted R2 (root mean square error) was 0.61 (0.31 s), 0.45 (0.32 m), 0.58 (0.15 m) and 0.41 (0.75 logs) for the 30-m dash, seated chest pass, standing long jump, and flamingo balance test, respectively making these models useful when physical fitness tests are not feasible. CONCLUSIONS: We highlighted the respective role of chronological age, sex, anthropometry, and body composition in physical fitness of children in the wide age range 6\u201312 years. Data confirm and expand on previous literature by showing with a strictly conservative statistical approach that chronological age is a main determinant of physical fitness of both boys and girls, sex playing a limited role. The role of anthropometry was even less important, and no role was found for body composition. These findings should be considered when planning/implementing motor development or physical education programs

Sporting activity does not fully prevent bone demineralization at the impaired hip in athletes with amputation

There is lack of information about bone mineralization at the lumbar spine and bilateral hips of athletes with unilateral lower limb amputation. The present study assessed for the first time the areal bone mineral density at the lumbar spine and at the hip of the able and impaired leg by means of Dual-Energy X-Ray Absorptiometry using a large sample (N = 40) of male athletes. Results showed that bone demineralization in athletes with unilateral lower limb amputation is found at the impaired hip but not at the lumbar spine and may therefore be site-specific. The extent of hip demineralization was influenced by the level of amputation, with about 80% of athletes with above knee amputation and 10% of athletes with below knee amputation showing areal bone mineral density below the expected range for age. Nevertheless, a reduced percentage of fat mass and a lower fat-to-lean mass ratio in the residual impaired leg as well as a greater amount of weekly training was positively associated with bone mineralization at the impaired hip (partial correlation coefficients = 0.377-0.525, p = 0.040-0.003). Results showed that participation in adapted sport has a positive effect on bone health in athletes with unilateral lower limb amputation but is not sufficient to maintain adequate levels of bone mineralization at the impaired hip in athletes with above-knee amputation. Accordingly, physical conditioners should consider implementing sporting programs, according to the severity of the impairment, aimed at improving bone mineralization at the impaired hip and improve body composition in the residual impaired leg

The limited impact of low-volume recreational dance on three-compartment body composition and apparent bone mineral density in young girls

Recreational dance is practiced worldwide as a multidimensional physical activity with a potential for prevention of a sedentary lifestyle and overweight/obesity. This study explored in young (7-15 year; n = 21) girls the effect of long-term (>1 year) exposure to recreational (2 h/w) dancing on three-compartment body composition. Recreational dancers (RD) were compared with recreational (≤4 h/w) artistic gymnasts (RG, n = 22) and physically active young girls not involved in structured extracurricular physical activity (control; C, n = 22), adjusting for confounding variables (age, body mass, menarche). We hypothesized for RD an intermediate body composition between RG and C. The three groups had similar age and body mass index. Body composition indices in RD were intermediate between that of C and RG, but RD values were not statistically significantly different vs. C. This agreed with the not statistically significant higher energy expenditure (MET-min/w) in RD vs. C (1357.7 ± 805.32 and 1090.9 ± 596.63, p = 0.172). In conclusion, long-term recreational dance exposure at low volume had limited positive effect on body composition of young girls vs. unstructured extracurricular physical activity. Future work will explore the potential of recreational dance at higher volume (3-4 h/w) to improve body composition in young girls

Long-term patterns of bone mineral density in an elite soccer player

Changes in bone mineral density (BMD) have been associated with association football (soccer) participation. Seasonal changes in BMD of soccer players have been proposed as well. However, previous investigations were based on short-term observations. Actually, longitudinal investigation of BMD in soccer players is lacking, possibly because of frequent inter-club transfer, changes in club policy or continued availability of the relevant facilities. Dual-energy X-ray Absorptiometry (DXA)-measured areal BMD (aBMD) was obtained during the competitive season in an elite soccer player along 10 consecutive years. Findings showed that (1) aBMD tends to increase with age, independently of body mass; (2) The right (preferred, kicking) leg has higher aBMD than the left (non-preferred, support) one; (3) Meaningful (i.e., >least significant change, LSC) changes in aBMD take place along the season; and (4) The off-season (transition) period has no effect on aBMD. Findings prompt for future research aimed at clarifying the long-term and seasonal patterns of bone characteristics in soccer in relation with age and type/dose of training. Season-around, long-term scrutiny of bone status in soccer players would help controlling for possible changes/asymmetries in bone mineralization/strength

Body composition and bone mineral density in athletes with a physical impairment

Background: The impact of the type and the severity of disability on whole-body and regional body composition (BC), and bone mineral density (BMD) must be considered for dietary advice in athletes with a physical impairment (PI). This study aimed to investigate the impact of the type and the severity of disability on BC, the pattern of distribution of fat mass at the regional level, and BMD in athletes with a PI. Methods: Forty-two male athletes with spinal cord injury (SCI, n = 24; age = 40.04 \ub1 9.95 years, Body Mass Index [BMI] = 23.07 \ub1 4.01 kg/m2) or unilateral lower limb amputation (AMP, n = 18; age = 34.39 \ub1 9.19 years, BMI = 22.81 \ub1 2.63 kg/m2) underwent a Dual-Energy X-Ray Absorptiometry scan. Each athlete with a PI was matched by age with an able-bodied athlete (AB, n = 42; age = 37.81 \ub1 10.31 years, BMI = 23.94 \ub1 1.8 kg/m2). Results: One-Way Analysis of Variance showed significant differences between the SCI, AMP and AB groups for percentage fat mass (%FM) (P < 0.001, eta squared = 0.440). Post-hoc analysis with Bonferroni's correction showed that athletes with SCI had significantly higher %FM vs. the AMP and AB groups (25.45 \ub1 5.99%, 21.45 \ub1 4.21% and 16.69 \ub1 2.56%, respectively; P = 0.008 vs. AMP and P < 0.001 vs. AB). The %FM was also significantly higher in the AMP vs. the AB group (P < 0.001). Whole-body BMD was negatively affected in SCI athletes, with about half of them showing osteopenia or osteoporosis. In fact, the mean BMD and T-score values in the SCI group (1.07 \ub1 0.09 g/cm2 and -1.25 \ub1 0.85, respectively) were significantly lower in comparison with the AB group (P = 0.001 for both) as well as the AMP group (P = 0.008 for both). The type of disability affected BC and BMD in the trunk, android, gynoid and leg regions in SCI athletes and the impaired leg only in AMP athletes. Conclusions: In conclusion, the type of disability and, partly, the severity of PI impact on BC and BMD in athletes with a PI. Nutritionists, sports medicine doctors, clinicians, coaches and physical conditioners should consider athletes with SCI or AMP separately. Athletes with a PI would benefit from specific nutrition and training programs taking into account the type of their disability

Anthropometric prediction of DXA-measured percentage of fat mass in athletes with unilateral lower limb amputation

To date there is no anthropometric equation specific to athletes with unilateral lower limb amputation to estimate the percentage of fat mass (%FM). This study investigated the accuracy of a set of anthropometric equations validated on able-bodied populations to predict the %FM assessed by-means of dual-energy x-ray absorptiometry (DXA) in athletes with unilateral lower limb amputation. Furthermore, a predictive anthropometric equation specific to athletes with unilateral lower limb amputation was developed from skinfold thickness measurements using DXA as the reference method for the estimation of the %FM. Twenty-nine white male athletes with unilateral lower limb amputation underwent a DXA scan and an anthropometric assessment on the same day. The %FM, calculated through several existing anthropometric equations validated upon able-bodied populations, was compared with the DXA-measured %FM (%FM_DXA). Accuracy and agreement between the two methods was computed with two-tailed paired-sample t-test, concordance correlation coefficient, reduced major axis regression and Bland-Altman analysis. A stepwise multiple regression analysis with the %FM_DXA as the dependent variable and age and nine skinfold thicknesses as potential predictors was carried out and validated using a repeated 10-fold cross-validation. A linear regression analysis with the sum of nine skinfolds as the independent variable was also carried out and validated using a repeated 10-fold cross-validation. The results showed that the anthropometric equations validated on able-bodied populations are inaccurate in the estimation of %FM_DXA with an average bias ranging from 0.51 to -13.70%. Proportional bias was also found revealing that most of the anthropometric equations considered, tended to underestimate/overestimate the %FM_DXA as body fat increased. Regression analysis produced two statistically significant models (P < 0.001 for both) which were able to predict more than 93% of total variance of %FM_DXA from the values of four skinfold measurements (i.e., thigh, abdominal, subscapular and axillary skinfold measurements) or from the sum of 9 skinfolds. Repeated cross-validation analysis highlighted a good predictive performance of the proposed equations. The predictive equations proposed in this study represent a useful tool for clinicians, nutritionists, and physical conditioners to evaluate the physical and nutritional status of athletes with unilateral lower limb amputation directly in the field

Physique and performance of young wheelchair basketball players in relation with classification

The relationships among physical characteristics, performance, and functional ability classification of younger wheelchair basketball players have been barely investigated to date. The purpose of this work was to assess anthropometry, body composition, and performance in sport-specific field tests in a national sample of Italian younger wheelchair basketball players as well as to evaluate the association of these variables with the players' functional ability classification and game-related statistics. Several anthropometric measurements were obtained for 52 out of 91 eligible players nationwide. Performance was assessed in seven sport-specific field tests (5m sprint, 20m sprint with ball, suicide, maximal pass, pass for accuracy, spot shot and lay-ups) and game-related statistics (free-throw points scored per match, two- and three-point field-goals scored per match, and their sum). Association between variables, and predictivity was assessed by correlation and regression analysis, respectively. Players were grouped into four Classes of increasing functional ability (A-D). One-way ANOVA with Bonferroni's correction for multiple comparisons was used to assess differences between Classes. Sitting height and functional ability Class especially correlated with performance outcomes, but wheelchair basketball experience and skinfolds did not. Game-related statistics and sport-specific field-test scores all showed significant correlation with each other. Upper arm circumference and/or maximal pass and lay-ups test scores were able to explain 42 to 59% of variance in game-related statistics (P<0.001). A clear difference in performance was only found for functional ability Class A and D