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Research progress in validation of clinical methods assessing body composition
Abstract
Anthropometry is the method of choice for estimating body composition in the clinical setting. The method can be accurate, and requires little time, space, equipment, or financial outlay. Although used extensively in epidemiological research, height/weight indices are not as accurate as skinfold and circumference measures for estimating body composition. The validity of estimating body density is enhanced by using a combination of skin-fold and circumference measures in a multiple-regression model. Some recently developed generalized equations may have a broader application for use in varied populations than several population-specific equations. The newer equations take into account the potential change in ratio of internal to external fat and bone density with age, and the nonlinear relationship between skinfold fat and body density. The validity of using skinfolds for estimating body density can be significantly affected by caliper selection and measurement procedures. Inter-observer errors appear to be the most problematic, with improper skinfold site selection causing the greatest variation among observers. To improve the validity of the anthropometric technique for use in the clinical setting, more precise standards and description of methods need to be developed.
... Inter-and intra-individual variability associated with the selection of skinfold sites, size/depth of the skinfold measurement and time delay in reading the calipers have all been shown to markedly reduce the accuracy of this procedure [5]. In the hands of highly trained and experienced testers the error associated with the use of skinfolds to predict body fatness is less than 3% [12]. However, inter-individual variability remains a major source of error associated with this technique. ...
... However, inter-individual variability remains a major source of error associated with this technique. Clearly the accurate assessment of body composition using skinfold calipers requires specially trained and experienced personnel [12]. This has somewhat limited the widespread application of skinfold assessment as a field-based tool and has led to the development of an alternative technique for the determination of body composition known as bioelectrical impedance analysis (BIA). ...
... Seven skinfold sites (triceps, biceps, chest, subscapula, abdomen, suprailiac, thigh) were measured in rotating order three times each on the right side of the body to the nearest 0.5 mm; the median value was used for analysis [9]. Each skinfold was grasped firmly with the thumb and the index finger holding the caliper perpendicular to the fold approximately one centimeter away from the thumb and the finger [12]. The measurement sites were identified following Jackson and Pollock [6]. ...
The aims of this study were to assess the validity of four skinfold equations and bioelectrical impedance analysis and underwater weighing (UWW) in female college students. The subjects were 30 female students of physical education from the Shahid Chamran University of Ahvaz, Iran, aged 22-26 years (mean age = 22.73 ± 0.908 years, body height = 1.63 ± 0.043 m, body mass = 21.87 ± 2.62 kg/m 2). Relative body fat percent (%BF) based on underwater weighing was used as the validity criterion. Each participant's %BF was assessed via the UWW on the basis of bioelectrical impedance and four skin fold equations. Body density and percent body fatness were determined using four commonly used skinfold thickness measurements: Jackson-Pollock (J-P) 3-and 7-site tests; Durnin-Womersley (D-W) 4-site test; and Sloan 2-site test (S). The statistical analysis used the Pearson correlation coefficient and paired sample T test, standard error of the estimate (SEE) and total error (TE). The analysis results revealed no significant differences with skinfold measurements using the Durnin-Womersley test (P = 0.117, r = 0.947, SEE = 1.4709, TE = 1.5112). Statistically significant differences were found between the BIA and Sloan test, Jackson-Pollock 3-site and 7-site test results and hydrostatic weighing results. The achieved results revealed that the Durnin-Womersley 4-site test was the most precise body fat estimation method.
... However, to achieve generalization, the model needs to be tested in a different sample, a process known as cross-validation [36]. This strategy was described by Pollock and Jackson [124], who made a reference to a study from 1968 that, already in that year, recommended performing a cross-validation using an independent subsample of the original group that has not been used in the development of the equations. Another way to check the cross-validation results is using statistical methods, such as the PRESS and jackknife procedures, which can indicate the predictive ability of a regression model and are conceptually equivalent to data-splitting methods, where, for example, an independent sample is randomly selected from the original sample that derived the equation and used for cross-validation [123]. ...
... References from different authors show variations in the anatomical sites that may lead to different results for the same measurement, which is a limitation of anthropometric measurements [143]. The need to standardize measurement procedures has been discussed for decades [158] to ensure high standards and consistency [124]. Lohman et al. [131] reported their concern about the Anthropometric Standardization Reference Manual, which was published in 1988 but has not been reissued since 2000. ...
Assessing the body composition of children and adolescents is important to monitor their health status. Anthropometric measurements are feasible and less expensive than other techniques for body composition assessment. This study aimed to systematically map anthropometric equations to predict adipose tissue, body fat or density in children and adolescents and to analyze methodological aspects of the development of anthropometric equations using skinfolds.
We included 78 reports and 593 anthropometric equations. The samples consisted of healthy individuals, people with different diseases or disabilities, and athletes from different sports. Dual-energy X-ray absorptiometry (DXA) was the reference method most commonly used in developing equations. Triceps and subscapular skinfolds were the anthropometric measurements most frequently used as predictors in the equations. Age, stage of sexual maturation and peak height velocity were used as complementary variables in the equations. Our scoping review identified equations proposed for children and adolescents with a great diversity of characteristics. In many of the reports, important methodological aspects were not addressed, a factor that may be associated with equation bias.
... Lung volumes were estimated using the BodPod software and BF% estimates were obtained after 2 successful attempts. Because the ABC equation applies to all ages and racial groups (18), the Siri equation (15) was chosen to calculate BF% as it is often considered a generalized equation (12) and allowed for a more equitable comparison. ...
... The administrator then located the appropriate landmarks for each International Journal of Exercise Science http://www.intjexersci.com 1278 site at the chest, abdomen, thigh, midaxillary, subscapular, triceps, and suprailiac (12). The administrator grasped the skin fold between the thumb and index finger 2-cm above the measurement site, pulling the skin and the underlying subcutaneous tissue away from the muscle. ...
The aim of this study was to compare body fat percentage (BF%) of women measured using the U.S. Army standard body composition assessment (ABC) and two common laboratory measures of body composition to evaluate the efficacy of ABC within this population. The BF% of 27 women (21.5 ± 1.8 years) was assessed using the 7-site skinfold, air plethysmography, and ABC measurements. The initial physical fitness test (IPFT) was used to determine if participants met the criteria required for admittance into basic combat training. A repeated measures ANOVA identified differences in BF% between the three assessment methods, (F (2, 52) = 22.83, p < .001, η2p = .47). Pairwise comparisons revealed that mean BF% obtained using the ABC (29.3 ± 7.7 %) was significantly higher (p = .042) than BF% measured using air plethysmography (26.9 ± 8.4 %). ABC and air plethysmography measured BF% was significantly higher (both p < .001) than BF% obtained from skinfold assessment (22.2 ± 5.9 %). Of the 27 total participants, 4 (14.8%) passed IPFT but failed to meet the Army body composition standards using the ABC method. The primary findings of this study suggest that the overestimation of BF% by the ABC method could lead to an unnecessary delay in enlistment for women approaching the upper threshold of the Army’s acceptable body composition standards. Alternative methods of assessing body composition in this population should be explored. However, skinfold assessment does not appear to be a suitable alternative to the ABC.
... High level of fat mass is indicative of obesity Sources: [19,[31][32][33][34][35][36][37][38][39][40]. ...
... Alternatively, sum of the skin fold fat thicknesses in millimetre together with age can also be used to estimate total body fat using appropriate charts for percent fat estimates for men or women. In the 1980s, Jackson and Pollock developed tables that relate body fat, age and skin fold thicknesses [35] and many researchers have validated or improved this method of estimating body fat [36][37][38]. ...
The obesity epidemic has been widespread in many countries, and has several adverse consequences. So many factors, some probable, others verified and documented, are known to contribute to the obesity problem in developed and developing countries. Nutritionists and other health professionals need to be skilled in understanding these various causes and their health implications. They should also be able to assess excessive body weight in clinical and other settings. Armed with this knowledge, health professionals should therefore be able to advise consumers and clients struggling with weight management on cost-effective preventive strategies to prevent or reduce incidence of obesity. In addition, nutritionists should be able to advise food manufacturers to make and market healthy food products. This paper will address the growing concern on obesity epidemic by reviewing the presumed and published or proven causes of obesity and the various methods for measurement of obesity. Strategies for preventing obesity will also be discussed. Such strategies would include health education, lifestyle changes, physical activity, diet and behavior modifications as well as reading food labels and proper food selection. Preventive strategies for obesity and overweight when properly implemented are very cost effective especially at personal and community levels and will ensure good health and wellness in many populations.
Assessment; Obesity; Epidemic; Overweight; Presumed; Proven causes; Prevention; Weight management; Health & Wellness
... High level of fat mass is indicative of obesity Sources: [19,[31][32][33][34][35][36][37][38][39][40]. ...
... Alternatively, sum of the skin fold fat thicknesses in millimetre together with age can also be used to estimate total body fat using appropriate charts for percent fat estimates for men or women. In the 1980s, Jackson and Pollock developed tables that relate body fat, age and skin fold thicknesses [35] and many researchers have validated or improved this method of estimating body fat [36][37][38]. ...
The obesity epidemic has been widespread in many countries, and has several adverse consequences. So many factors, some probable, others verified and documented, are known to contribute to the obesity problem in developed and developing countries. Nutritionists and other health professionals need to be skilled in understanding these various causes and their health implications. They should also be able to assess excessive body weight in clinical and other settings. Armed with this knowledge, health professionals should therefore be able to advise consumers and clients struggling with weight management on cost-effective preventive strategies to prevent or reduce incidence of obesity. In addition, nutritionists should be able to advise food manufacturers to make and market healthy food products. This paper will address the growing concern on obesity epidemic by reviewing the presumed and published or proven causes of obesity and the various methods for measurement of obesity. Strategies for preventing obesity will also be discussed. Such strategies would include health education, lifestyle changes, physical activity, diet and behavior modifications as well as reading food labels and proper food selection. Preventive strategies for obesity and overweight when properly implemented are very cost effective especially at personal and community levels and will ensure good health and wellness in many populations.
... No entanto, diversas discussões que tange as investigações no campo da antropometria implica no questionamento sobre o custo e aplicabilidade dos métodos e equipamentos na estimativa da composição corporal em diferentes populações [5][6][7][8][9] . É fato, que uma equação de estimativa da composição corporal oriunda de população, necessita ser analisada e validada antes de ser aplicada em outra população 5,7 . ...
... No entanto, diversas discussões que tange as investigações no campo da antropometria implica no questionamento sobre o custo e aplicabilidade dos métodos e equipamentos na estimativa da composição corporal em diferentes populações [5][6][7][8][9] . É fato, que uma equação de estimativa da composição corporal oriunda de população, necessita ser analisada e validada antes de ser aplicada em outra população 5,7 . A importância de se analisar a aplicabilidade de equações de estimativa da composição corporal na população brasileira, centra-se na utilização de método de baixo custo como a estimativa do %G, pelo índice de massa corporal (IMC), a perimetria e as dobras cutânea, que permitem diagnosticar os aspectos nutricionais 10,11 , como também, fomentar parâmetros para estabelecer as cargas de trabalho nos programas de exercícios como forma de prevenção de doenças degenerativas não transmissíveis 2,12 . ...
Introduction: The estimation of body composition is an important study field in the prognosis and diagnosis of degenerative diseases. Objective: To analyze the applicability of the Body Adiposity Index (BAI) and the skinfold thickness method. Methods: The sample consisted of 19 young adult women with a mean age 24.53 +/- 2.65 years, who underwent anthropometric measurements (circumferences and skinfold thickness) and dual energy X-ray absorptiometry (DEXA). The estimated values were compared to the reference value by using the paired t test and by analysis of the level of association between the methods through the Pearson correlation. The level of significance was p<0.05. Results: Showed no significant differences between the fat percentage estimated by the BAI and the reference values, however had moderate level of association (r=0.627). Nevertheless, the skinfold thickness method showed statistically significant difference (p>0.05) with a strong association level (r=0.879). Conclusion: Although the BAI does not show difference to the estimated values, it is clear that further studies on the applicability of the method in the Brazilian population are necessary.
... Anthropometric measurements were taken at various times in the 22 Measurements of WC and HC were taken as recommended by Pollock and Jackson. 19 BMI (ratio of body mass to height) was obtained in kg/m². ...
Introduction: Body composition assessment (BCA) using anthropometric measurements (AM) is used to monitor the nutritional and health status of the elderly. As predictor variables, MAs must be valid, practical, and quick, as they favor adherence and avoid possible resistance and embarrassment on the part of those being assessed and being minimally invasive. Objective: To develop and validate equations using accessible and minimally invasive anthropometric measurements for BCA in elderly women. Methods: 100 women (68.1±6.15 years) were randomly assigned to two groups: validation (n=40; 68.1±6.15 years); and estimation (n=60; 68.4±6.70 years). DXA was selected as the criterion measure, and MAs (body mass, height, skinfolds, circumferences) were selected
as predictor variables. Means were compared using the paired Student’s t-test; correlations were verified using Pearson’s r-test; equations using Multiple Linear Regression. The level of agreement between the groups’ results was checked using the Bland-Altman technique. Results: Two equations developed and tested (E3 and E4) met the validation criteria as they showed adequate correlation coefficients (E3: r=0.73; E4: r=0.70), low constant errors
(E3: EC= -0.56; E4: EC=-0.90), total error (E3: ET=3.22; E4: ET=3.06) lower than the Standard Error of Estimate (E3:
EPE=3.24; E4: EPE=3.21), indicating no statistically significant difference between the two BCA techniques observed (p>0.05). The Bland-Altman technique showed good agreement between the results of the two techniques.
Conclusion: Two were validated: E3 (%Gdxa= - 41.556 + 4.041(BMI) + 0.165(DcCox) - 0.440(CircCox) + 0.269(Circ-
Quad) - 0.053(BMI)²); and E4 (%GdxaE4= 15.329 + 1.044(BMI) -1.055(CircAbra) + 0.282(CircQuad) + 0.164(DcCox)
- 0.262(CircCox)). Notably, the small number of measurements were located in areas of the body that are easily accessible and have little body exposure, which minimizes possible embarrassment and favors adherence by the
elderly. Level of Evidence IV; Correlational study to build a predictive equation.
... Anthropometric measurements were taken at various times in the 22 Measurements of WC and HC were taken as recommended by Pollock and Jackson. 19 BMI (ratio of body mass to height) was obtained in kg/m². ...
Introduction
Body composition assessment (BCA) using anthropometric measurements (AM) is used to monitor the nutritional and health status of the elderly. As predictor variables, MAs must be valid, practical, and quick, as they favor adherence and avoid possible resistance and embarrassment on the part of those being assessed and being minimally invasive.
Objective
To develop and validate equations using accessible and minimally invasive anthropometric measurements for BCA in elderly women.
Methods
100 women (68.1±6.15 years) were randomly assigned to two groups: validation (n=40; 68.1±6.15 years); and estimation (n=60; 68.4±6.70 years). DXA was selected as the criterion measure, and MAs (body mass, height, skinfolds, circumferences) were selected as predictor variables. Means were compared using the paired Student's t-test; correlations were verified using Pearson's r-test; equations using Multiple Linear Regression. The level of agreement between the groups’ results was checked using the Bland-Altman technique.
Results
Two equations developed and tested (E3 and E4) met the validation criteria as they showed adequate correlation coefficients (E3: r=0.73; E4: r=0.70), low constant errors (E3: EC= −0.56; E4: EC=-0.90), total error (E3: ET=3.22; E4: ET=3.06) lower than the Standard Error of Estimate (E3: EPE=3.24; E4: EPE=3.21), indicating no statistically significant difference between the two BCA techniques observed (p>0.05). The Bland-Altman technique showed good agreement between the results of the two techniques.
Conclusion
Two were validated: E3 (%Gdxa= −41.556 + 4.041(BMI) + 0.165(DcCox) − 0.440(CircCox) + 0.269(CircQuad) − 0.053(BMI)²); and E4 (%GdxaE4= 15.329 + 1.044(BMI) −1.055(CircAbra) + 0.282(CircQuad) + 0.164(DcCox) − 0.262(CircCox)). Notably, the small number of measurements were located in areas of the body that are easily accessible and have little body exposure, which minimizes possible embarrassment and favors adherence by the elderly. Level of Evidence IV; Correlational study to build a predictive equation.
Keywords:
Body Fat Distribution; Aging; X-Rays; Anthropometry
... Subjects: Nine female students (Mean ± SD age 22.5 ± 2.3, weight 55.5 ± 5.5 kg, stature 161.2 ± 6.3 cm, and 15.29 ± 3.28%) attending the water fitness course of the university of motor sciences, participated in the study. Body composition was assessed by measuring 7 skin fold site according to the formula of Pollock and Jackson [14]. ...
... Anthropometric data were collected on the initial visit to the laboratory. The body fat percentage was determined by measuring skinfolds thickness at three sites 29 1RM records were calculated using the Equation (1) below. 30 The exercise protocol was designed according to the American College of Sports Medicine (ACSM) recommendations 31 and recent meta-analysis results. ...
This study aimed to investigate the chronic effects of green tea (GT) extract and resistance training (RT) on ambulatory and office blood pressure (BP), heart rate (HR), and rate‐pressure product (RPP) in a sample of Iranian women with high‐normal/stage 1 hypertension. Forty‐four middle‐aged sedentary women participated in this randomized, double‐blind, placebo‐controlled study. They were randomly assigned to one of four groups: GT and RT (GR, n = 11), RT (n = 10), GT (n = 10), or control (n = 13). Three weeks of GT consumption were followed by six weeks of the interaction with RT. GR and RT groups performed two circuits of RT at %50 of 1RM two days per week. RT and control groups also received placebo (maltodextrin) with the same timing. The changes of each variable from baseline to post‐intervention were compared between the groups using the ANOVA test, and effect size (ES) statistic was also calculated. In comparison with the control group, significant reductions were found for office systolic BP (SBP, 8%, ES = 1.22), and 24 h‐SBP (5%, ES = 1.2) in the RT group. However, GR group showed significant decreases in office SBP (10.5%, ES = 1.45), mean BP (8%, ES = 1.11), RPP (13%, ES = 1.47), 24 h‐SBP (5%, ES = 1.21), and 24 h‐RPP (10%, ES = 1.15). The interaction of regular RT and GT consumption seems to induce more beneficial effects on some important parameters including MBP and RPP when compared to RT or GT alone.
... The skin folds were evaluated at the following points: triceps, subscapular area, axilla (midaxillary), supra iliac area, abdomen, thigh, and chest. From the data obtained, the following parameters were calculated: sum of the seven skin folds (ΣSF) (mm) and the body fat percentage (% BF), estimated according to the age group [16]. ...
Background
Normotensive premenopausal women show a vagal predominance of cardiac autonomic modulation, whereas age-matched men show a predominance of sympathetic modulation. However, some women develop systemic arterial hypertension (SAH) even with preserved ovarian function. Our hypothesis is that these women may have cardiovascular autonomic parameters similar to those of hypertensive men, even when subjected to pharmacological treatment. We aimed to investigate cardiovascular autonomic control and baroreflex sensitivity (BRS) in hypertensive premenopausal women and age-matched men.
Methods
One hundred volunteers between 18 and 45 years of age were assigned to two groups (50 participants each): a hypertensive group including patients with a history of SAH for at least 6 months (25 men and 25 women), who were under treatment with monotherapy (losartan, 25–50 mg/kg); and a normotensive group (25 men and 25 women). Anthropometric, hemodynamic, metabolic, and autonomic cardiovascular assessments were performed focusing on BRS, autonomic modulation of heart rate variability (HRV), and blood pressure variability (BPV).
Results
On HRV analysis, women showed higher values of high-frequency (HF) oscillations in absolute and normalized units, lower values of low-frequency (LF) in normalized units, and lower LF/HF ratio, as compared with men. When the normotensive and hypertensive groups were compared, hypertensive groups showed lower values of total variance and of LF and HF bands in absolute units. On BRS, hypertensive groups showed lower values than the normotensive group.
Conclusion
Regardless of blood pressure control through pharmacological treatment, hypertensive patients continued to have reduced HRV compared to normotensive, and hypertensive men had more autonomic impairment than hypertensive premenopausal women.
... From the data obtained, the following parameters were calculated: sum of the seven DC (ΣDC) (mm) and the body fat percentage (% BF), estimated by age group. [16] Cardiorespiratory Function Test An incremental treadmill exercise test (Super ATL Millenium®, Inbramed/Inbrasport, Porto Alegre, RS, Brazil) was performed following the Balke protocol, previously described. [17] Electrical activity was monitored by electrocardiogram (ECG) with nine leads (CM5, DI, DII, V1-V6). ...
Background
Normotensive women before menopause showed a vagal predominance of cardiac autonomic modulation, while age-matched men showed a sympathetic modulation predominance. However, some women develop systemic arterial hypertension (SAH) even with preserved ovarian function. Our hypothesis is that these women may have cardiovascular autonomic parameters like those of hypertensive men, even when subjected to pharmacological treatment. We aim to investigate the cardiovascular autonomic modulation balance and baroreflex sensitivity (BRS) in hypertensive women with preserved ovarian function and age-matched men.
Methods
One hundred volunteers between 18 and 45 years of age, were assigned to two groups of fifty: Hypertensive group, with a SAH history for at least 6 months (25 men and 25 women) treated with monotherapy (losartan, 25-50mg/kg) and normotensive group (25 men and 25 women). Anthropometric, hemodynamic, metabolic, and autonomic cardiovascular assessments were performed focusing: BRS, autonomic modulation of heart rate variability (HRV) and blood pressure variability (BPV).
Results
The results showed that HRV analysis, women showed higher values of HF oscillations in absolute and normalized units, and lower values of LF in normalized units and LF/HF ratio compared to men. When normotensive and hypertensive groups were compared, hypertensive groups showed lower values of total variance, LF and HF bands in absolute units. There were similar in BPV. However, hypertensive groups showed lower BRS values when compared to normotensive group.
Conclusion
The results indicate that hypertensive groups even with blood pressure controlled through pharmacological treatment, continued to have reduced HRV than normotensive, and hypertensive women have minor cardiovascular autonomic impairment than men.
... Although we do not evaluate the standard error of measurements, a possible cause for our results for inter-observer would be the higher values were relative measurement technical error happen in regions of higher fat accumulation (34), that is higher for medial thigh and suprailiac SF than for triceps SF. In additional, inter-observer errors seem to be the most problematic, with inadequate choice of SF site, causing the greatest variation among observers (35), and obesity may influence the skinfold measurements reliability, especially in those cases in which skinfold size approaches the upper limit of the measurement range of the caliper (36). In other studies, compared with female subjects, the inter-and intra-observer variabilities were both greater on the male subjects for %BF was obtained using the ∑SF sites (bicep, triceps, subscapular, and suprailiac) (37). ...
Objective
To assess the utility of bioimpedance (BIA) and skinfolds thickness (SF) in body fat percentage measuring (%BF) compared to the reference method dual-energy x-ray absorptiometry (DXA) in Brazilian reproductive age women, as well as to estimate of inter- and intra-observer precision for SF.
Subjects and methods
170 women aged 18-37 years with BMI between 18 and 39.9 kg/m² were selected for this cross-sectional study. Body density was evaluated through equations proposed by Jackson, Pollock and Ward (1980) (EqJPW) and Petroski (1995) (EqPET), and %BF was estimated by BIA, DXA and Siri’s formula (1961). The SF were measured by two separate observers: A and B (to determine inter-observer variability), who measured the folds at three times with 10-minute interval between them (to determine intra-observer variability – we used only observer A).
Results
The %BF by DXA was higher than those measured by SF and BIA (p<0.01, for all) of 90 volunteers. The Lin coefficient of agreement was considered satisfactory for %BF values obtained by EqJPW and BIA (0.55) and moderate (0.76) for sum of SF (ΣSF) values obtained by EqJPW and EqPET. No agreement was observed for the values obtained by SF (EqJPW and EqPET), BIA and DXA. Analysis of inter- and intra-observer of 59 volunteers showed that different measures of SF thickness met acceptability standards, as well as the % BF.
Conclusion
BIA and SF measurements may underestimate %BF compared with DXA. In addition, BIA and SF measurements are not interchangeable with DXA. However, our results suggest the equation proposed by Jackson, Pollock and Ward (three skinfolds) compared to BIA are interchangeable to quantify the %BF in Brazilian women in reproductive age. Furthermore, our results show acceptable accuracy for intra- and inter-observer skinfold measurements. Arch Endocrinol Metab. 2020;64(3):257-68
... The skin fold thicknesses (triceps, biceps, suprailiac, abdomen, midaxiller, pectoral, subscapular, thigh, calf and suprapatella) were measured with the help of a caliper to calculate body fat percentages of the athletes. Each measurement was repeated three times and averages were taken (7)(8)(9). The weight and height scale were used to collected weight and height measurement. ...
Background: Follow up of the nutrition consumption of young soccer players is of great importance not only for their sport performance, but also for the protection of health, physical growth and development. Aim: The objective of this study was to evaluate the nutritional sufficiency status of elite young male athletes in the pre-competition period. Methods: Three-day food consumption and anthropometric measurements of the elite young athletes in the pre-competition period were recorded for 26 male voluntary athletes from a pro-professional soccer team based in Ankara Turkey. Results: The mean height of the athletes were calculated as 175.2±6.8 cm, weight 67.3±5.9 kg, body mass index (BMI) as 21.9±1.3 kg/m ² and body fat percentage 6.2±1.7. It was determined that the athletes received an average of 3225±692 kcal energy daily whereas their mean energy expenditures per day were 3322±240 kcal. The ratios of energy received from carbohydrate, protein and fats were 53.6%, 16.2%, and 30.2%, respectively. Carbohydrate and protein consumption/day/ kg body weight were 6.3±1.7 g and 1.9±0.5 g, respectively. It was determined that vitamin D consumption was inadequate for 92.3% of the athletes and calcium consumption was inadequate for 50% of the athletes. On the other hand, all of the athletes consumed vitamins B 2 , B 6 and B 12 as well as phosphorus, iron and zinc above recommended quantities. Conclusions: Nutrient consumption of young athletes at the beginning of their professional life must be monitored by a qualified dietitian and each athlete must have an individual dietary plan. Nutrition education must be arranged and the athletes’ families must be included in these trainings.
... Ältere Studien konn- ten zeigen, dass die Genauigkeit der Messung der Hautfaltendicke maßgeblich von der Erfahrung und praktischen Übung des Untersuchers abhängt. Vor allem der Ort der Messung, die Größe und Tiefe der Hautfalte und die Verzögerung im Ablesen des Calipers sind Grund für die großen inter-und intraindividuellen Schwankungen [124][125][126][127] Gleichzeitig müssen die Voraussetzungen für eine adäquate Reaktion in Form eines Medikamenten-Regimewechsels in diesen Ländern ermöglicht werden. ...
Knapp über 6 Mio. HIV-Infizierte leben in Südafrika, darunter ca. 410.000 Kin-der unter 15 Jahren. Somit ist es das am meisten von HIV betroffene Land weltweit. Seit 2004 haben die Infizierten, initiiert durch das staatliche Roll-Out Programm, kostenfrei Zugang zur HAART. Aufgrund der begrenzten Ressour-cen sind die Therapieschemata und das Patientenmonitoring eingeschränkt. Im pädiatrischen Patientenkollektiv beinhaltete die Erstlinien-Therapie zum Zeitpunkt dieser Untersuchung Stavudin und Azidothymidin - beides ältere Medikamente, die eng mit der Entwicklung eines Lipodystrophie-Syndroms verknüpft werden. Das Lipodystrophie-Syndrom fasst verschiedene Fettumverteilungsstörungen (die Lipoatrophie und Lipohypertrophie) sowie Fettstoffwechselstörungen zusammen. Neben erheblichen Auswirkungen auf die Compliance der Patienten fürchtet man frühzeitig kardiovaskuläre Komplikationen. Die geschätzte Prävalenz dieses Syndroms bei HIV-positiven Kindern beträgt circa 30% und erlangt so besondere Relevanz. Aufgrund der mangelnden Reversibilität der Fettumverteilung ist eine frühzeitige Diagnose, gefolgt von einer therapeutischen Maßnahme entscheidend. Die Diagnose des Lipodystrophie-Syndroms erfolgt in der Regel durch einen pädiatrischen HIV-Spezialisten; an apparativen Untersuchungsmethoden stehen DEXA-Scans und Einzelschicht-CT-Aufnahmen zur Verfügung. In Südafrika können diese Untersuchungen, außerhalb von Forschungseinrichtungen, aufgrund der begrenzten finanziellen Mittel nicht durchgeführt werden und auch die Anzahl der pädiatrischen HIV-Spezialisten ist begrenzt. Daher ist es von großer Bedeutung, ein einfaches Screening-Werkzeug zu entwickeln, um das Lipodystrophie-Syndrom auch in Ressourcen-armen Gebieten frühzeitig diag-nostizieren zu können. In der vorliegenden Arbeit wurde, gerade im Hinblick auf die Entwicklung eines einfachen Lipodystrophie-Syndrom-Screening-Werkzeuges, die Vergleichbarkeit anthropometrischer Messungen bestimmt. Daneben wurden Risikofaktorenanalysen durchgeführt. Insgesamt erfolgten hierzu an 72 HIV-positiven Kindern ausführliche anthropometrische Messungen. Die Messungen wurden jeweils von einer professionellen Ernährungsberaterin und einer eigens eingearbeiteten Medizinstudentin erfasst. Die Vergleichbarkeit wurde anhand eines gepaarten t-Testes und Intraklassenkorrelationen ermittelt. Zusätzlich erfolgte eine Datenerhebung aus den vorliegenden Patientenakten. Die als Screening-Methode favorisierten Hautfaltendicken-Messungen zur Ermittlung des subkutanen Fettgewebes, zeigten im t-Test, bis auf die Bestim-mung der Hautfaltendicke des Abdomens und Oberschenkels, signifikante Unterschiede. Die Intraklassenkorrelation konnte jedoch für alle Messwerte eine gute bis sehr gute Übereinstimmung finden. Unter Verwendung der hier vorgestellten Daten konnten wir in einer Folgestudie zeigen, dass sich die Hautfaltendicke-Messung im Bereich des Bizeps trotzdem zur frühzeitigen Detektion einer Lipodystrophie eignen könnte, da der Einfluss der hier aufgezeigten Unterschiede nur gering ist [99]. Diese Erkenntnis hat große Relevanz und lässt hoffen, dass in Zukunft auch bei Patienten in ländlichen Gebieten Südafrikas die Diagnose eines Lipodystrophie-Syndroms frühzeitig gestellt und mit einem Medikamentenwechsel reagiert werden kann. Anhand der z-Scores der Taillen-zu-Hüft (WHR) Verhältnisse und der Brust-zu-Arm (TAR) Verhältnisse erfolgte die Einteilung der Studienteilnehmer in Lipodystrophie-positiv und Lipodystrohie-negativ. Kleine negative Zusammen-hänge ergaben sich zwischen dem Krankheitsstadium sowie der Baseline CD4-Zellzahl und den Merkmalen einer Lipodystrophie. Ähnliche Ergebnisse sind auch in anderen Studien zu finden. Man geht davon aus, dass ein niedrigeres Krankheitsstadium mit einer besseren Compliance und somit mit einem höheren Risiko zur Entwicklung eines Lipodystrophie-Syndroms verbunden ist. Weiterhin scheint sich eine bessere immunologische Ausgangssituation protektiv auf die Entwicklung eines Lipodystrophie-Syndroms auszuwirken. Eine weitere Korrelation ergab sich außerdem zwischen der LPV/r Dosierung und dem WHR-z-Score, welches den bereits bekannten Zusammenhang zwischen der Einnahme von Proteaseinhibitoren mit der Entwicklung einer Lipohypertrophie stützt. Anhand von Kreuztabellen konnte weder für Stavudin, noch für Azidothymidin ein eindeutiger Hinweis für ein erhöhtes Risiko in der Entwicklung eines Lipodystrophie-Syndroms gefunden werden. Die Kriterien zur Einteilung in Lipodystrophie-positiv und Lipodystrophie-negativ wurden aus zwei unabhängigen Studien übernommen und erlauben für sich genommen nicht die Diagnose einer Lipodystrophie. Die anhand dieser Einteilung vorgenommene Risikofaktorenanalyse ist deswegen nur bedingt aussagefähig, hinzu kommen die geringe Fallzahl und die heterogene Patientengruppe dieser Studie. Aufgrund der Kombinationstherapie aus mindestens drei antiretroviralen Medikamenten erschwert auch dies die Charakterisierung der Risikofaktoren für die Entwicklung eines Lipodystrophie-Syndroms. Diese ist jedoch, neben der frühen Diagnose, entscheidend um präventive Maßnahmen ergreifen zu können. Trotz der vorhandenen Limitationen dieser Studie konnten Risikofaktoren identifiziert werden, welche sich auch in der Literaturrecherche bestätigen ließen. Aufgrund verschiedener Berichte über ein ungünstiges Nebenwirkunsgprofil, mit unter anderem hohem Risiko für die Entwicklung eines Lipodystrophie-Syndroms, wurde das Medikament Stavudin aus den südafrikanischen Therapieleitlinien herausgenommen. Weiterhin konnte eine ausreichende Verlässlichkeit der anthropometrischen Messungen gezeigt werden, welche entscheidend für die Entwicklung eines einfachen LDS-Screening-Werkzeugs ist. Diese Daten wurden 2013 im „Pediatric Infectious Disease Journal“ veröffentlicht. Für die Zukunft wären größere Studien mit besseren diagnostischen Möglich-keiten wünschenswert, um das Lipodystrophie-Syndrom bestmöglich zu charakterisieren und Risikofaktoren zu benennen. Gerade für das pädiatrische Patientenkollektiv scheint es besonders im Hinblick auf die lebenslange Therapiedauer wichtig Medikamentennebenwirkungen frühzeitig zu erkennen, zu reduzieren und Alternativmedikamente bereitzustellen. Für ressourcenarme Länder ist dies eine besondere Herausforderung. Hier stehen nur begrenzt Ausweichmedikamente zur Verfügung.
... Volleyball, basketball, and tennis players retain the percentage of fat usually at 14-17%, and throwers -at 18-22%. The amount of fat in women's bodies is usually 6-10% higher than in those of men [60,66]. ...
The article dwells on theoretical and methodological foundations for the identifi cation and development of sports talents, i.e. searching for promising personalities capable of achieving high results in sports, incorporating them into an eff ective system of long-term training and appropriate orientation of their training based on individual potential, abilities, and inclinations. It shows that sports selection and orientation are permanent processes closely related to tasks and contents of each stage of long-term preparation. The article reveals organizational and content-related peculiarities of sports selection exemplifi ed by the achievements of modern science and successful practices inherent to sports of the former USSR and the GDR and modern sports of the USA, China, Germany, and Australia, i.e. the countries where this issue has been and is being given the highest priority. A set of criteria were analysed in detail, which are used in the selection and orientation process, including indicators that allow assessing the health of athletes, peculiarities of their body types, their age and sexual development, capabilities of various energy supply systems, their ability to master sports techniques and develop motor qualities, their mental peculiarities, and others. Much attention was paid to the genetic aspects of sports selection and orientation along with the importance of athletes' body types for achieving high sports results. The relationships were shown between the selection criteria, their tasks, and the contents of each stage of long-term preparation, which is of fundamental importance for an objective assessment of an athlete's potential and rational orientation of the subsequent preparation. The potential and inclinations of athletes in relation to the specifi cs of various sports can be identifi ed towards the end of the puberty period with a reasonable certainty. Depending on their predisposition to achievements in diff erent events, young athletes can be divided into 5 groups: sprinters, mixed type with a predisposition to sprint work, mixed type with mixed abilities, mixed type with a predisposition to long-distance or long-term work, and long-distance performers. Keywords: identifi cation of sports talents, sports selection, sports orientation, potential, inclinations, talent, giftedness, stages of long-term preparation of athletes.
... (Jackson & Pollock, 1978). These original equations were based off of a 2C Siri model that was used often in hydrodensitometry measurements (Jackson & Pollock, 1978;Jackson & Pollock, 1984. ...
Background: Currently, body composition (BC) assessment is usually performed to diagnose disease states and accurately estimate certain types of tissues. In athletes, performing BC assessments helps gauge training and nutrition programs to see if they are adequately meeting the athlete’s needs to improve performance. Annual Dual Energy X-ray Absorptiometry (DXA) scans before the start of an athlete’s season can help identify an athlete’s preparedness or health before training begins. Objective: To assess the preseason BC of four collegiate sports: Men’s basketball, men’s baseball, women’s volleyball, and women’s soccer, for Fat Mass (FM), bone mineral density BMD), Fat-Free Mass (FFM), and visceral adipose tissue (VAT). Methods: DXA (Lunar iDXA, GE Healthcare) scans were performed before the start of pre-season training for Men’s Basketball, Baseball, Women’s Volleyball, and Women’s Soccer. End-season DXA scans were performed after the end of the regular season for Men’s Basketball and Baseball athletes. Visceral Adipose Tissue was measured using CoreScan software provided by GE and Fat Mass Index (FMI) and Fat-Free Mass Index (FFMI) were calculated from scanned values. Results: Between the various sports, there were several significant differences that were apparent. Height and percentage of Fat Mass (%BF) were significantly different between all sports except Women’s Volleyball and Women’s Soccer. BMI, VAT, and FFMI were significantly different between males and females. Changes over a season showed increased BMD in Men’s Basketball (2.79 to 2.99 Z-score, pre to end of season scan respectively; p < 0.001). No other observations were noticed to be significant. Conclusions: Sports-specific training and sex have large influences on the body composition of athletes. FMI and FFMI are two indices that may have a stronger indication to health than parameters considered for those who are sedentary and non-active. Female athletes have little to no amounts of VAT and this warrants further investigation.
... Our preliminary software program was has been developed in Matlab and will require the end-user to enter demographic information along with the selection of a front and side photograph previously saved on the computer. Furthermore, our method requires little human input during the image capture and processing procedures, thereby reducing biases inherent in other field methods such as visual estimation and skinfold measurement, which require training and re-training [11,[14][15][16]35]. Lastly, no specialized equipment is required beyond a simple digital camera and a green backdrop makes our portable method more convenient than other methods. ...
Background/Objectives
Body mass index (BMI) is a proxy for obesity that is commonly used in spite of its limitation in estimating body fatness. Trained observers with repeated exposure to different body types can estimate body fat (BF) of individuals compared to criterion methods with reasonable accuracy. The purpose of this study was to develop and validate a computer algorithm to provide a valid estimate %BF using digital photographs.
Subjects/Methods
Our sample included 97 children and 226 adults (age in years: 11.3±3.3; 38.1±11.6, respectively). Measured height and weight were used (BMI in kg/m²: 20.4±4.4; 28.7±6.6 for children and adults, respectively). Dual x-ray absorptiometry (DXA) was the criterion method. Body volume (BVPHOTO) and body shape (BSPHOTO) were derived from two digital images. Final support vector regression (SVR) models were trained using age, sex, race, BMI for % BFNOPHOTO, plus BVPHOTO and BSPHOTO for %BFPHOTO. Separate validation models were used to evaluate the learning algorithm in children and adults. The differences in correlations between %BFDXA, %BFNOPHOTO and %BFPHOTO were tested using the Fisher’s Z-score transformation.
Results
Mean BFDXA and BFPHOTO were 27.0%±9.2 vs. 26.7%± 7.4 in children and 32.9± 10.4% vs. 32.8%±9.3 in adults. SVR models produced %BFPHOTO values strongly correlated with %BFDXA. Our final model produced correlations of rDP = 0.80 and rDP = 0.87 in children and adults, respectively for %BFPHOTO vs. %BFDXA. The correlation between %BFNOPHOTO and %BFDXA was moderate, yet statistically significant in both children rDB = 0.70; p <0.0001 and adults rDB = 0.86; p<0.0001. However, the correlations for rDP were statistically higher than rDB (%BFDXA vs. %BFNOPHOTO) in both children and adults (children: Z = 5.95, p<0.001; adults: Z = 3.27, p<0.0001).
Conclusions
Our photographic method produced valid estimates of BF in both children and adults. Further research is needed to create norms for subgroups by sex, race/ethnicity, and mobility status.
... Skinfold measurements were based on the average of two trials and obtained on the right side in serial fashion by the same investigator. Body density was estimated using the age-adjusted equation of Pollock and Jackson (1984). The three-compartment Siri equation was used for % body fat (Siri, 1961). ...
THE EFFECTS OF CREATINE SUPPLEMENTATION ON SPRINT
RUNNING PERFORMANCE AND SELECTED HORMONAL RESPONSES
Hassan FARAJI*, Hamid ARAZI**, Dariush SHEIKHOLESLAMI VATANI ***
& Mehdi HAKIMI**
* Department of Physical Education & Sport Science, Islamic Azad University Marivan
Branch, Marivan, Iran
**Faculty of Physical Education and Sport Science, University of Guilan, Rasht, Iran
***Department of Physical Education & Sport Science, University of Kurdistan,
Sanandaj, Iran
ABSTRACT
The purpose of this study was to determine the influence of short-term creatine
supplementation on sprint running performance (100 and 200 m) and circulating
hormone [growth hormone (GH), testosterone and cortisol] concentrations. Twenty
amateur male runners were randomly divided into a creatine supplementation
group, or placebo group. Subjects were provided with capsules containing either
creatine monohydrate or identical powdered cellulose placebo. Daily creatine
monohydrate supplementation was 20 g/day parceled into three equal dosages to be
consumed with each major meal. Subjects were tested for performance and resting
blood hormone concentrations before and after six days. A double-blind research
design was employed in this study. After this creatine loading, the mean running
performance time of the creatine supplementation group decreased significantly in
the 100 m, but not the 200 m. Serum GH, testosterone, and cortisol concentrations
were not affected by creatine supplementation. It can therefore be concluded that
although short-term creatine supplementation was found to improve sprint
performance in the 100 m in amateur runners, this performance improvement did not
appear to be hormonally mediated.
Key words: Sprint performance; Creatine supplementation; Hormonal
responses; Creatine loading.
... Thirteen highly trained trail runners from local running clubs participated and performed the three different exercise tests (age 31 ± 6 years, height 179 ± 6.4 cm, weight 69.2 ± 7.9 kg, BMI 21.6 ± 2.1 kg/m 2 , body fat ( %) (using a 7-site skinfold test by Jackson and Pollock) 8.9 ± 4.6) [34]. We defined highly-trained runners as athletes participating at a high level in local and regional competitions but not part of the national team, on the ITRA performance index, or a participant in previous ITRA Trail World Championships [47]. ...
Trail running places specific physiological demands on the human body due to its uphill and downhill running sections. We developed and investigated a more sport-specific trail exercise test protocol (inclination and speed incremental protocol), and compared it to two standard exercise test protocols (horizontal step and ramp protocol) in thirteen highly trained trail runners (age 31±6 years, height 179±6.4 cm, weight 69.2±7.9 kg, BMI 21.6±2.1 kg/m2). The maximum oxygen uptake (VO2max) measured during the trail test (62.5±5.9 ml·kg−1·min−1, [95% CI: 59.0-66.1]) was significantly higher compared to both the step test (60.1±5.3 ml·kg−1·min−1, [95% CI: 56.8-63.3], p=0.024) and the ramp test (59.7±5.5 ml·kg−1·min−1, [95% CI: 56.4-63.0], p=0.028). Time to task failure was significantly shorter in the trail test (557±73 s, [95% CI: 512-601]) compared to both the step test (1378±152 s, [95% CI: 1286-1470], p<0.001) and the ramp test (605±95, [95% CI: 547-662], p<0.001). Other physiological measurements obtained were similar. The trail test was the preferred choice in our group of trail runners. This study supports the implementation of the trail test in practice, and recommends that its validity be evaluated further.
... Skinfold thickness (triceps, supra-iliac and mid-thigh) was measured to the nearest millimetre using the Lange skinfold calliper and results were utilised to calculate percentage body fat. 14 Waist and hip circumferences were measured using a plastic dressmaker's tape 20 and the waist-to-hip ratio was calculated. The body mass index (BMI) was calculated using the measurements of height and weight according to the Bray formula. ...
Objective. To measure the daily energy expenditure in employees previously identified as having ≥2 risk factors for chronic disease, and to identify potential risk-reducing interventions for implementation within or outside the workplace. Design. A total of 122 employees with ≥2 risk factors for chronic disease identified in an in-house screening programme were invited to participate in a 6-month health management programme. Physical assessments included anthropometric measurements, blood pressure, blood glucose and cholesterol estimations, and bicycle ergometry. Participants were invited to wear a ‘metabolic armband' (Body Media SenseWear Pro Armband®) for 6 days. Metabolic measures included active and total energy expenditure (AEE, TEE), and daily MET levels (metabolic equivalents expressed as kcal/kg/hour). Differences were explored between genders, and relationships sought between energy expenditure, lifestyle and anthropometric data. Setting. A corporate working environment. All measures and assessments were carried out in the in-house fitness facility. Interventions. The health management programme involved physical assessments and personalised weight and activity management plans. Main outcome measures. TEE per day, duration and quantification of physical activity, METS, AEE, number of steps per day and body position recording. Relationships were explored between the latter and anthropometric measures such as body mass index (BMI) and percentage body fat. Result. Altogether 53 (43%) of the eligible subjects volunteered for the 6-month programme and 49 enrolled for the metabolic armband study. The males were more active than the females, but both had BMI and body fat estimates that categorised them as overweight to obese. METS and AEE were positively correlated with duration of exercise rather than intensity, and negatively correlated with BMI. In a stepwise regression analysis for the total group 77% of the variance in MET levels was accounted for by per cent body fat and steps per day. Multivariate analysis by gender (with per cent body fat as the dependent variable) suggested that males would have to increase the duration of vigorous exercise in order to reduce body fat, while females would benefit from sitting less, sleeping more, and increasing the duration of moderate exercise. Conclusion and clinical relevance. In a self-selected sample involving motivated individuals, the SenseWear® armband provided information that would be useful in directing further research in women, focusing on sleeping pattern and moderately increasing activity levels. South African Journal of Sports Medicine Vol. 20 (2) 2008: pp. 40-43
... The current study used 3-point skin fold measures' method of body fat composition estimation, whose accuracy is subjective by being dependent on the observer. This may affect reproducibility of results [46]. In the current study, this was overcome by having the same researcher conduct all measurements on the multiple participants for consistency. ...
Chronic disease, more prevalent among the elderly, is influenced by body composition and cardio-metabolic physiognomies. Aim: In this study, body composition, cardiovascular, and metabolic function in sedentary but healthy Kenyan individuals of ≥ 50 years was determined. Methods: For 53 volunteers from Eldoret, Kenya, their biological, demographic characteristics, metabolic functions, cardiovascular performance, and body composition measurements were done before they were subjected to a Shuttle Run Test (SRT). Following SRT, their cardiovascular parameters were measured, and maximal oxygen consumption estimated. Fasting blood sugars and lipid profiles were measured after a 12-hour fast. Results: For males and females, respectively, the following parameters were recorded: average ages 55.5 ± 3.0 and 53.9 ± 3.0 years, BMI > 24.9 Kg/M 2 in 67% and 88.5%, waist-to-height ratio ≥ 0.5 in 70% and 88.5%, waist–hip ratio 78% (≥ 0.90) and 38.5% (≥ 0.85), and blood pressure >140/90 mmHg in 22.2% and 23.1%. Pre-diabetic to diabetic values were found in 70.4% males and 88.5% females. The percent body fat was 22.3 ± 8.0 and 38.3 ± 4.69 in males and females, respectively. Lipid profile for males and females, respectively, showed high Total Cholesterol (TC) in 48.1% and 42.3%, anomalous Low Density Lipoproteins (LDL) in 29.6% and 26.9%, lower than normal HDL levels in 29.6% and 23.1%, elevated triglycerides in 22.2% and 7.7%, abnormal TC/HDL ratio in 44.4% and 38.5% females, higher LDL/HDL in 33.3% and 34.6%, and critical Triglycerides/HDL levels in 7.4% and 3.8%. Overall, 51.9% of males and 53.8% of females showed features consistent with metabolic syndrome. Conclusion: Majority of elderly sedentary Kenyans have body compositions and cardio-metabolic profiles below that for good cardiopulmonary fitness.
... Body fat percentage is the relative amount of fat to lean body tissue on the body. This was measured with the Lange skinfold calipers using the 3-site measurement [43]. The Brozek equation was used to quantify each participant's percentage [24]. ...
... Se midieron, a través del plicómetro de marca Sanny ® , los siguientes pliegues cutáneos: tríceps, bíceps, subescapular, pectoral, axilar medio, cresta ilíaca, supraespinal, abdomen, anterior del muslo y pantorrilla. El porcentaje de grasa (%G) fue obtenido mediante el protocolo de Pollock et al. 13 . Los linfocitos TCD4 fueron evaluados con citometría de flujo usando equipos FACSCalibur, y los datos bioquímicos fueron medidos mediante el lector ELISA, colesterol total (COLESTAT enzimático AA) y HDL (MONOFASE AA PLUS). ...
Objetivo: El objetivo de este estudio descriptivo fue analizar la relación entre los ejercicios de fuerza y los parámetros hematológicos, virológicos y antropométricos.
Método: Fueron analizadas 40 personas de ambos sexos que viven con VIH/SIDA, con edades entre 20 y 50 años, de la ciudad de Mossoró (Rio Grande do Norte, Brasil). Todas fueron evaluadas antes y después de ser sometidas a un programa de ejercicios de fuerza. Los datos fueron analizados con el programa SPSS 20.0 en su versión en portugués.
Resultados: Fue posible encontrar diferencia significativa (p
... Body fat percentage is the relative amount of fat to lean body tissue on the body. This was measured with the Lange skinfold calipers using the 3-site measurement [43]. The Brozek equation was used to quantify each participant's percentage [24]. ...
Purpose:
To determine the effect of comparing a non-incentivized reward system with an incentivized reward system using combined positive and negative rewards on physical activity, attendance, and health and performance outcomes.
Methods:
15 Previously sedentary faculty and staff of a large public research university participated in two separate 12-week exercise interventions and wore a program accelerometer throughout the entire day during the 12weeks. During the first intervention, there were no incentives offered to participants. The second intervention consisted of an incentivized program. Positive reinforcements included various rewards for meeting achievements related to physical activity levels. A program rebate worth _amp_$lt;0.001) and push-ups (p=0.018). All other variables revealed no differences between conditions or from pre to post testing. There was no difference between conditions with physical activity or attendance.
Conclusion:
No differences in physical activity or health-related variables were found within the incentivized and non-incentivized conditions.
... Skinfold measurements were based on the average of two trials and obtained on the right side in serial fashion by the same investigator. Body density was estimated using the age-adjusted equation of Pollock and Jackson (1984). The three-compartment Siri equation was used for % body fat (Siri, 1961). ...
The aim of this study was to determine the effects of glutamine supplementation on performance, and hormonal changes during an 8-week resistance training program in non athlete male students. Thirty healthy non athlete male (age 21.25 ± 1.6 years, height 173.2 ± 3.2 cm, body mass 72.8 ± 2.8 kg, VO2max 43.48± 2.38 ml·kg-1·min-1) were randomly divided into a glutamine supplementation (GL) group (n=15), and a placebo (PL) group (n=15). Each group was given either glutamine or a placebo in a double blind manner to be taken orally for eight weeks (0.35 g/kg/day). GL and PL groups performed the same weight training program 3 days, each week for 8 weeks. The training consisted of 3 sets of 8 repetitions, and the initial weight was 80% of the pre-1RM. Subjects were tested for performance and blood hormone concentrations before and after the 8-week period. Both groups increased their performance however the GL group showed significantly greater increases in upper and lower body strength, explosive muscular power, blood testosterone, GH and IGF-1 when compared to the PL group; however, cortisol concentrations were significantly more reduced in GL group when compared to the PL group. It can, therefore, be concluded that within 8 weeks glutamine supplementation during resistance training was found to increase performance (explosive muscular power, muscle strength) and improved body composition (increased body mass, fat-free mass and reduced body fat).
... The skinfold thickness measurement method requires cheaper equipment but typically demands more training for the examiners. Inter-and intra-individual variability associated with the selection of skinfold sites, the size/depth of the skinfold measurement, and the time delay in reading the calipers have all been shown to markedly reduce the accuracy of this method (8). However an experienced examiner can reduce this variability and can effectively choose the appropriate equation for estimating the percentage of body fat. ...
Introduction: This study compared arm-to-leg bioelectrical impedance analysis (BIA) method and skinfold measurement in estimating the percent body fat (%BF) in male professional soccer players. Methods: Twenty eight healthy professional soccer players (aged 27.4 ± 5.3 years; ht 180 ± 7.0 cm; wt 76.6 ± 6.3 kg; and BMI 23.66 ± 1.5) from division one Greek League was assessed. Body composition was determined using seven skinfold measures using the Brozek et al. (1963), predictive equation. BIA measurements were determined using a BC-418 Segmental Body Composition Analyzer. Measurements were scheduled at the same time of the day (8:00-10:00) with the athletes presenting in a fasted state and after a full day rest. Results: All subject completed both BIA and skinfold measurements and using a pearson correlation coefficient between methods was r = 0.56 (p < 0.01). Percent body fat values differed between techniques (p < 0.001). BIA overestimated %BF by 27.81%. Conclusion: The study demonstrated that the arm-to-leg BIA system does not accurately assess %BF when compared to the skinfold measurement method in soccer players.
RESUMO Introdução: A avaliação da composição corporal (ACC) com auxílio das medidas antropométricas (MA) é utilizado no acompanhamento do estado nutricional e de saúde das populações idosas. As MAs como variáveis preditoras, devem ser válidas, práticas e rápidas, pois favorecem a adesão e evitam possíveis resistências e constrangimento das avaliadas, além de minimamente invasivas. Objetivo: Desenvolver e validar equações utilizando medidas antropométricas de fácil acesso e minimamente invasivas, para ACC de idosas. Métodos: 100 mulheres (68,1±6,15 anos) distribuídas aleatoriamente por dois grupos: validação (n=40; 68,1±6,15 anos); estimativa (n=60; 68,4±6,70 anos). Como medida critério selecionou-se a DXA, como variáveis preditoras as MAs (massa corporal, estatura, dobras cutâneas, circunferências). As médias foram comparadas com o teste t de Student pareado; as correlações verificadas com o teste r Pearson; as equações com a Regressão Linear Múltipla. O nível de concordância entre os resultados dos grupos foi verificado com a técnica Bland-Altman. Resultados: Duas equações desenvolvidas e testadas (E3 e E4) atenderam aos critérios de validação, pois, apresentaram coeficientes de correlação adequados (E3: r=0,73; E4: r=0,70), erros constantes baixos (E3: EC= −0,56; E4: EC=-0,90), erro total (E3: ET=3,22; E4: ET=3,06) menores que o Erro Padrão de Estimativa (E3: EPE=3,24; E4: EPE=3,21), indicando não existir diferença estatisticamente significativa entre as duas técnicas de ACC observadas (p>0,05). A técnica Bland-Altman demonstrou boa concordância entre os resultados das duas técnicas. Conclusão: Duas equações foram validadas: E3 (%Gdxa= −41,556 + 4,041(IMC) + 0,165(DcCox) – 0,440(CircCox) + 0,269(CircQuad) – 0,053(IMC)²); e E4 (%GdxaE4= 15,329 + 1,044(IMC) −1,055(CircAbra) + 0,282(CircQuad) + 0,164(DcCox) – 0,262(CircCox)). Destaca-se o fato do reduzido número de medidas situarem-se em áreas corporais de fácil acesso e de pouca exposição corporal, que minimizam possíveis constrangimentos e favorecem a adesão das idosas. Nível de Evidência IV; Estudo correlacional para construção de equação preditiva.
This study aimed to expose the effect of whole body vibration training for 12 weeks on some physical fitness characteristics of sedentary female students. Sixty volunteer sedentary female students (average age=21,23 ± 3,77) were included in the study. Participants were randomly assigned to groups of 20: Whole Body Vibration Training Group (WBVTG), Whole Body Vibration Free Training Group (WBVFTG) and Control Group (KG). The training was continued for 4 days a week with having a break on alternate days. As for pre-test at 10.10.2016, mid-test at 18.11.2016 and post-test at 30.12.2016 are applied on participants with measurements of body fat (BF), body mass index (BMI), skinfold (S), body fat percentage (BFP), back strength (SK), leg strength (LS), right (RHGS) and left hand grip strength (LHGS), vertical jump (VJ) and blood lactate difference (BLD). The obtained data analysis was done by ANOVA for comparison of related groups and by one-way ANOVA for comparison of unrelated repeated measurements. There was a significant in group difference in BW, BMI, BFP, RHGS, BS and BLD in WBVFTG when WBVTG showed same results in BW, BMI, BFP, RHGS and LHGS, BS, LG, VJ and BLD. Between groups comparisons for the pre-test in RHGS, BD; for mid-test BW, BMI, RHGS, LHGS, BS, LP, VJ; for the post-test BLD were determined. Both trainings (WBVT, WBVF) have crucial effects on some physical fitness parameters. But the effect after WBVT put forward acute effects when compared to WBVFT.
Letrozole is an aromatase inhibitor, used to treat post‐menopausal women with hormone receptor‐positive or unknown advanced breast cancer. It is prohibited in sport because it is used together with androgen anabolizing steroids to avoid their adverse effects. In case of adverse analytical finding, it may be important to distinguish between repetitive use due to voluntary administration and occasional use, possibly due to involuntary intake. With the objective to identify the dose capable of producing a positive hair testing, and to apply these results to the scenarios of letrozole inadvertent ingestion by an athlete, this study aims at investigating the urinary excretion and incorporation into hair of single doses of letrozole.
Seven subjects were recruited for an excretion study of letrozole and its metabolite bis(4‐cyanophenyl) methanol (M1) in urine, after the consumption of 0.62 mg, 1.25 mg, and 2.5 mg of letrozole, and to investigate the incorporation in hair after ingestion of 0.62 mg and 2.5 mg of letrozole. Urine and hair samples were also obtained from two women in chronic therapy.
Urinary concentrations of letrozole and its metabolite M1 were lower in subjects administered once with 0.62 mg, 1.25 mg or 2.5 mg letrozole than in women in regular therapy with 2.5 mg/day. In hair collected after single dosage, concentrations of 16‐60 pg/mg were detected while in women in chronic therapy concentrations were higher than 160 pg/mg all along the hair shaft. Hair analysis turned to be a promising possibility for the discrimination of letrozole repetitive use vs occasional/inadvertent administration.
Background:
Running is a popular recreational activity and additional weight is often carried in backpacks on longer runs. Our aim was to examine running economy and other physiological parameters while running with a 1kg and 3 kg backpack at different submaximal running velocities.
Methods:
10 male recreational runners (age 25 ± 4.2 years, VO2peak 60.5 ± 3.1 ml·kg-1·min-1) performed runs on a motorized treadmill of 5 minutes durations at three different submaximal speeds of 70, 80 and 90% of anaerobic lactate threshold (LT) without additional weight, and carrying a 1kg and 3 kg backpack. Oxygen consumption, heart rate, lactate and RPE were measured and analysed.
Results:
Oxygen consumption, energy cost of running and heart rate increased significantly while running with a backpack weighing 3kg compared to running without additional weight at 80% of speed at lactate threshold (sLT) (p=0.026, p=0.009 and p=0.003) and at 90% sLT (p<0.001, p=0.001 and p=0.001). Running with a 1kg backpack showed a significant increase in heart rate at 80% sLT (p=0.008) and a significant increase in oxygen consumption and heart rate at 90% sLT (p=0.045 and p=0.007) compared to running without additional weight. While running at 70% sLT running economy and cardiovascular effort increased with weighted backpack running compared to running without additional weight, however these increases did not reach statistical significance.
Conclusions:
Running economy deteriorates and cardiovascular effort increases while running with additional backpack weight especially at higher submaximal running speeds. Backpack weight should therefore be kept to a minimum.
To assess the validity of skinfofd thickness estimates of body fatness in formerly morbid obese adults, 23 patients (17 women, 6 men) who had completed a protein-sparing modified fast were studied. Mean ± SD weight loss was 60.7 ± 20.6 kg for men and 42.6 ± 11.5 kg for women. Body density and percent body fatness were determined after weight loss according to four commonly used skinfold equations: Pollock (P); Durnin-Rahaman (D-R); Durnin-Womersley (D-W); and, Jackson-Pollock (J-P). The validity of these measurements was assessed by hydrostatic weighing, which revealed a percent body fatness of 20.4 ± 6.5 for men and 29.8 ± 8.4 for women. The mean difference and total error (square root of the x̄ of squared deviations) between skinfold predicted and hydrostatically-determined percent body fatness for each skinfold equation were: P, 2.0 and 4.9; D-R, 4.2 and 6.6; D-W, 7.1 and 8.4; and, J-P, 0.7 and 4.4. With the exception of the latter equation, all significantly overestimated (p < 0.01) hydrostatically-determined percent body fatness. Conclusion: Select skinfold equations may result in a marked overestimation of body fatness in formerly obese patients.
Introduction: Since methods to resistance exercise (RE) prescription uses percentage of one repetition maximum test (1-RM), it is crucial checking if the same %1 RM generates similar intensity and performance. Thus, the objective of this study was to compare the number of repetitions and total load in uni-vs. bilateral, upper vs. lower limbs exercises in different percentages of 1RM. Methods: Twenty one healthy men (23.2 ±5.8 years, 84.3 ± 7.6 kg, 182.2 ± 6.5 cm, 11.4 ± 4.8 % boy fat; one year of RE experience (4-5 h/week) volunteered. After 1 RM tests the maximum number of repetitions with 70%, 80% and 90 % of 1 RM in uni and bi-lateral exercises were performed. Results: Number of repetitions of uni-lateral Leg Press was significantly greater for 80% of 1 RM (P<0.05), while the total load was lower for 70% of 1 RM comparing with bilateral Leg Press. Increase in number of repetitions in bilateral contractions for 80% and 90% of 1 RM, while the total load was increased in 70% of 1 RM with Uni-lateral when compared with bilateral knee flexion. The Uni-lateral Scott exercise showed significant differences with 70% of 1 RM load both in numbers of repetitions and in total load. Conclusion: In 80% and 90% of 1 RM number of repetitions is higher in lower compared with upper limbs exercises, while in 70% no differences were found. It seems that single-joint perform less repetitions than multi-joint exercises (e.g. Leg Extension vs. Leg Press) and upper limbs showed more number of repetitions and total load in 70% of 1 RM.
INTRODUCTION: Physical fitness is an important attribute in soldiers because military work may be physically demanding. To ensure that military personnel are “fit to fight”, soldiers are typically selected and evaluated based on fitness tests, and physical training and physical activity are emphasized to maintain or develop physical fitness. Existing literature has primarily described fitness and activity levels in full-time soldiers, while reserve soldiers are less frequently investigated. No previous studies have reported physical fitness or physical activity levels in the Norwegian Home Guard (HG) force. When describing fitness and activity levels, it is important that the validity and reliability of the measurement tools are known, preferably for the population of interest. Some of
the frequently used methods have not been sufficiently evaluated for validity and reliability in military populations, and such studies are therefore needed.
AIMS: The main aim of this thesis is to describe physical fitness and physical activity in a nationally representative sample of Norwegian HG soldiers. An additional aim is to investigate the validity and reliability of two primary outcome measures from the HG study: the 20 meter shuttle run test (20 m SRT) for aerobic fitness and a bioelectrical impedance analysis (BIA) method for body fat estimations.
METHODS: This thesis is comprised of three studies: a method comparison study of the 20 m SRT, a method comparison study of body composition field methods, and a cross-sectional study of physical fitness and physical activity in HG soldiers. The method comparison study of the 20 m SRT was conducted in two stages. Stage one included 38 male HG soldiers and consisted of test–retest reliability analysis, as well as generation of a new maximal oxygen uptake (V̇O2max) prediction equation based on a comparison between 20 m SRT performance and directly measured V̇O2max. In stage two, our new 20 m SRT equation and five alternative existing equations were cross-validated on 28 male cadets. The method comparison study of body composition field methods included test–
retest reliability analysis of percent body fat estimated from skinfolds, single frequency and multifrequency BIA, and a combined skinfold and single frequency BIA method. Validity of these field methods, using several body fat prediction equations, was evaluated against dual-energy X-ray absorptiometry (DXA). Sixty-five male and female cadets, soldiers and officers were included in this study. The cross-sectional study on physical fitness and physical activity in HG soldiers was conducted on 799 male HG soldiers from five HG districts and 38 troops. Aerobic capacity, body composition and anthropometrics were measured during HG military training. Physical activity was objectively measured with the SenseWear Armband monitor during HG military training and the succeeding civilian week. Some soldiers did not carry out all measurements; for example, only 299 soldiers were included in the analysis of physical activity during HG training.
RESULTS: The 20 m SRT produced a test–retest reliability intraclass correlation coefficient (ICC) of 0.95 (0.90, 0.97) and a 95 % limits of agreement (LoA) of ± 3.1 mL∙kg-1∙min-1. Pearson correlation between estimated V̇O2max from the 20 m SRT and directly measured V̇O2max was r = 0.82 and r = 0.69 in HG soldiers and cadets, respectively. The corresponding LoA were ± 7.2 and ± 6.2 mL∙kg-1∙min-1, respectively. A discrepancy of up to 23 % for mean estimated V̇O2max was demonstrated among previously published 20 m SRT equations. Test–retest ICC for estimated percent body fat from skinfold and BIA was typically ≥ 0.95, while test–retest LoA were normally between ± 1─3 body fat percentage points. Estimated percent body fat from skinfold and BIA typically correlated to DXA with a Pearson r ≈ 0.80─0.90. The LoA varied from 3.5─8.0 body fat percentage points, dependent on method, equation, and gender. Mean 20 m SRT run performance in Norwegian HG soldiers was 70 shuttles, which corresponds to a V̇O2max of approximately 50 mL∙kg-1∙min-1. Mean body mass index, waist circumference and body fat were 26.1 kg∙m-2, 94.0 cm and 19.7 %, respectively. Differences in anthropometrics and aerobic fitness related to type of HG force or military rank were generally small or nonexistent. In terms of physical activity, the commonly recommended 10,000 steps per day were reached by 44 % of the soldiers during civilian life. The median time spent in ≥ very vigorous intensity physical activity (> 9 metabolic equivalents) was 4 minutes per day during civilian life. The HG soldiers spent significantly more time in moderate intensity physical activity during HG training compared to civilian life, but less time in vigorous and very vigorous physical activity.
CONCLUSIONS: The 20 m SRT appears to be a sufficiently reliable test for practical use in the military. In terms of validity, the 20 m SRT may estimate V̇O2max accurately on group level, but a relatively large measurement error should be accounted for at the individual level. No single body composition field method stood out as clearly more reliable and valid than the other methods. Many equations seem reliable for general use in the military – yet, a relatively large measurement error must be accounted for at the individual level when predicting percent body fat. Moreover, reliability and validity varied substantially among some of the body composition equations. Two out of three HG soldiers reached commonly recommended values for aerobic fitness, body composition and anthropometrics. However, such general fitness recommendations may not necessarily be valid for HG soldiers. The low volume of high intensity physical activity during HG training indicates relatively low aerobic demands during HG military service. Thus, the majority of the HG soldiers seem to have a sufficient physical capacity to carry out the pre-planned jobs designated for HG soldiers. Increased focus on physical fitness and physical activity could still be valuable to physically prepare HG soldiers for more unforeseen tasks with possibly higher demands than observed during HG training.
Arch Med Deporte 2016;33(6): Resumen Introducción: Como los métodos para la prescripción de ejercicios con sobrecarga utilizan el porcentaje de 1 RM, son crucial verificar si el mismo porcentaje de 1 RM equivale a intensidades similares y al mismo rendimiento. Por lo tanto, el objetivo de este estudio fue compara el número de repeticiones y la carga total en ejercicios unilaterales y bilaterales, de las extremidades superiores e inferiores, con diferentes porcentajes de 1 RM. Método: Veintiúno varones sanos (23,2 ± 5,8 años; 84,3 ± 7,6 kg; 182,2 ± 6,5 cm; 11,4 ± 4,8% de masa grasa; 1 año de experien-cia, 4-5 h por semana) participaron voluntariamente en el estudio. Después de los tests de 1 RM, los participantes realizaron tests de repeticiones máximas al 70%, 80% y 90% de 1 RM en ejercicios unilaterales y bilaterales. Resultados: El número de repeticiones de press de pierna unilateral tuvo un incremento significativo con el 80% de 1RM (p<0,05). Sin embargo, la carga total al 70% de 1RM fue menor en comparación con el press de pierna bilateral. El incremento en el número de repeticiones en las contracciones bilaterales al 80% y al 90% de 1RM, demostraron un aumento del trabajo total cuando comparado con la condición unilateral al 70%. El ejercicio " Scott " unilateral presentó diferencias significativas al 70% de 1RM, tanto en el número de repeticiones como en el trabajo total. Conclusión: En las condiciones de 80% y 90% de 1RM, el número de repeticiones es mayor en los miembros inferiores, mien-tras que al 70% no hubo diferencias significativas. Parece que sólo el grupo unilateral hacía un menor número de repeticiones cuando comparado con los ejercicios multi-articulares, por ejemplo, extensión de pierna vs. pressión de pierna. Los miembros superiores mostraron un mayor número de repeticiones y carga total al 70% de 1RM. Summary Introduction: Since methods to resistance exercise (RE) prescription uses percentage of one repetition maximum test (1-RM), it is crucial checking if the same %1RM generates similar intensity and performance. Thus, the objective of this study was to compare the number of repetitions and total load in uni-vs. bilateral, upper vs. lower limbs exercises in different percentages of 1RM. Methods: Twenty one healthy men (23.2 ± 5.8 years, 84.3 ± 7.6 kg, 182.2 ± 6.5 cm, 11.4 ± 4.8 % boy fat; one year of RE experience (4-5 h/week) volunteered. After 1RM tests the maximum number of repetitions with 70%, 80% and 90 % of 1RM in uni and bilateral exercises were performed. Results: Number of repetitions of unilateral Leg Press was significantly greater for 80% of 1RM (P<0.05), while the total load was lower for 70% of 1RM comparing with bilateral Leg Press. Increase in number of repetitions in bilateral contractions for 80% and 90% of 1RM, while the total load was increased in 70% of 1RM with Unilateral when compared with bilateral knee flexion. The Unilateral Scott exercise showed significant differences with 70% of 1RM load both in numbers of repetitions and in total load. Conclusion: In 80% and 90% of 1RM number of repetitions is higher in lower compared with upper limbs exercises, while in 70% no differences were found. It seems that single-joint perform less repetitions than multi-joint exercises (e.g. Leg Extension vs. Leg Press) and upper limbs showed more number of repetitions and total load in 70% of 1RM.
Objectives: The aim of the present study was to analyze and correlate muscle strength of the back and front squat with performance in the movements of weightlifting snatch and the clean in CrossFit® practitioners. Method: Twenty-two adults participated in this study and were divided according to their performance in the snatch and clean movements: stronger (29.6. ±. 4.4 years; 80.95. ±. 9.57. kg; 12.2. ±. 5.8% body fat; 2.4. ±. 0.9 training experience) and weaker (28.5. ±. 5.4 years; 79.4. ±. 6.8. kg; 13.6. ±. 3.5% body fat; 2.0. ±. 1.1 training experience). All volunteers completed one-repetition maximum tests, in separate days, in the following exercises: back squat, front squat, snatch and the first phase of the clean. Results: The volunteers classified with a superior performance in the snatch and clean presented a higher strength in the back squat (154.9. ±. 20.3. kg vs 132.7. ±. 11.6. kg; . p = 0.009) and front squat (139.0. ±. 14.5. kg vs 116.8. ±. 11.3. kg; . p = 0.002) as compared with the weaker volunteers. Additionally, there were strong correlations between relative strength in the back squat (r = 0.83; r = 0.76; . p = 0.001) and front squat (r = 0.73; r = 0.83; . p = 0.001) with the performance in the snatch and clean exercises, respectively. Conclusions: Therefore, a superior strength in basic exercises, such as back and front squat can contribute to weightlifting performance in CrossFit® practitioners. © 2016 Consejería de Turismo y Deporte de la Junta de Andalucía.
Resumo: Objetivos: O objetivo do presente estudo foi analisar e relacionar a força muscular do back squat e front squat com o desempenho nos movimentos de levantamento olímpico snatch e clean em praticantes de CrossFit®. Método: Participaram deste estudo 22 adultos, que foram divididos de acordo com o desempenho nos movimentos de snatch e clean: fortes (29.6 ± 4.4 anos; 80.95 ± 9.57 kg; 12.2 ± 5.8% de gordura; 2.4 ± 0.9 experiência de treinamento) e fracos (28.5 ± 5.4 anos; 79.4 ± 6.8 kg; 13.6 ± 3.5% de gordura; 2.0 ± 1.1 experiência de treinamento). Todos os voluntários realizaram em dias separados os testes de uma repetição máxima nos exercícios: back squat, front squat, snatch e clean. Resultados: Os voluntários classificados com o melhor desempenho no snatch e clean apresentaram maior força no back squat (154.9 ± 20.3 kg vs. 132.7 ± 11.6 kg; p = 0.009) e no front squat (139.0 ± 14.5 kg vs. 116.8 ± 11.3 kg; p = 0.002), quando comparados aos voluntários mais fracos. Além disso, foram observadas correlações fortes entre a força relativa do back squat (r = 0.83; r = 0.76; p = 0.001) e do front squat (r = 0.73; r = 0.83; p = 0.001) com a performance nos exercícios snatch e clean, respectivamente. Conclusões: Portanto, uma força superior em exercícios básicos, como o back squat e o front squat, podem contribuir para o desempenho do levantamento olímpico em praticantes de CrossFit®. Resumen: Objetivo: El propósito del presente estudio fue analizar y relacionar la fuerza muscular de la sentadilla por delante y por detrás con el rendimiento en los movimientos de halterofilia de arranque y de cargada en practicantes de CrossFit®. Método: Participaron en este estudio 22 adultos que fueron divididos de acuerdo con el rendimiento en los movimientos de arranque y cargada: fuertes (29.6 ± 4.4 años; 80.95 ± 9.57 kg; 12.2 ± 5.8% de grasa corporal; 2.4 ± 0.9 experiencia de entrenamiento) y débiles (28.5 ± 5.4 años; 79.4 ± 6.8 kg; 13.6 ± 3.5% de grasa corporal; 2.0 ± 1.1 experiencia de entrenamiento). Todos los voluntarios realizaron, en días diferentes, los test de una repetición máxima en los ejercicios: sentadilla por detrás, sentadilla por delante, arranque y cargada. Resultados: Los voluntarios clasificados con el mejor rendimiento en el arranque y en la cargada presentaron mayor fuerza en la sentadilla por detrás (154.9 ± 20.3 kg vs. 132.7 ± 11.6 kg; p = 0.009) y en la sentadilla por delante (139.0 ± 14.5 kg vs. 116.8 ± 11.3 kg; p = 0.002) cuando fueron comparados con los voluntarios más débiles. Además, se observaron correlaciones fuertes entre la fuerza relativa de la sentadilla por detrás (r = 0.83; r = 0.76; p = 0.001) y la sentadilla por delante (r = 0.73; r = 0.83; p = 0.001) con el rendimiento en los ejercicios de arranque y cargada, respectivamente. Conclusión: Por tanto, una mayor fuerza en ejercicios básicos, como la sentadilla por detrás y por delante, pueden contribuir para el rendimiento de los ejercicios olímpicos en practicantes de CrossFit®. Abstract: Objectives: The aim of the present study was to analyze and correlate muscle strength of the back and front squat with performance in the movements of weightlifting snatch and the clean in CrossFit® practitioners. Method: Twenty‐two adults participated in this study and were divided according to their performance in the snatch and clean movements: stronger (29.6 ± 4.4 years; 80.95 ± 9.57 kg; 12.2 ± 5.8% body fat; 2.4 ± 0.9 training experience) and weaker (28.5 ± 5.4 years; 79.4 ± 6.8 kg; 13.6 ± 3.5% body fat; 2.0 ± 1.1 training experience). All volunteers completed one‐repetition maximum tests, in separate days, in the following exercises: back squat, front squat, snatch and the first phase of the clean. Results: The volunteers classified with a superior performance in the snatch and clean presented a higher strength in the back squat (154.9 ± 20.3 kg vs 132.7 ± 11.6 kg; p = 0.009) and front squat (139.0 ± 14.5 kg vs 116.8 ± 11.3 kg; p = 0.002) as compared with the weaker volunteers. Additionally, there were strong correlations between relative strength in the back squat (r = 0.83; r = 0.76; p = 0.001) and front squat (r = 0.73; r = 0.83; p = 0.001) with the performance in the snatch and clean exercises, respectively. Conclusions: Therefore, a superior strength in basic exercises, such as back and front squat can contribute to weightlifting performance in CrossFit® practitioners. Palavras‐chave: Treinamento de força, Potência, Desempenho, Palabras clave: Entrenamiento de fuerza, Potencia, Rendimiento, Keywords: Strength training, Power, Performance
Nutritional assessment has been considered as a cornerstone of nutritional diagnosis, management, intervention and dietary planning. Specific criteria, methods and procedures should be used for different age groups through a person’s life cycle based on the requirements of each age group. Use of precise and accurate nutritional assessment tools and procedure to detect those who are malnourished or at risk of malnutrition will help dietitians to create an accurate dietary plan and intervention, which may help in quality of life improvement. This handbook includes the details of each assessment method for different age groups, from pregnancy to old age. It will be used as a quick, practical guide and reference for clinical dietitians. It includes dietary, anthropometric, biochemical and clinical assessments.
Screening and assessment of nutritional status is of paramount importance for the management of patients with chronic kidney disease (CKD), especially individuals undergoing maintenance dialysis. The complex nature of CKD and its associated adverse consequences lead to a unique constellation of nutritional and metabolic abnormalities that adversely affect the body’s protein and energy status. These abnormalities can be defined as protein-energy wasting (PEW), i.e. a state of decreased body stores of protein and energy fuels. There are several clinical, nutritional, and biochemical parameters that are associated with and frequently indicative of PEW in individuals with CKD. Among the biochemical indices, serum albumin or serum transthyretin (prealbumin) provide the best diagnostic and prognostic information. However, both are influenced by multiple conditions inherent to kidney disease. When combined with low visceral protein concentrations, low relative body weight, reduced total body fat or muscle mass or progressive weight loss are diagnostic of PEW. Several composite indices such as subjective global assessment can also be incorporated in screening for or diagnosing PEW. Protein intake can be estimated from the urea nitrogen appearance or, for dialysis patients, the protein equivalent of total nitrogen appearance (PNA or PCR). Measurement of dietary energy intake along with estimates of daily energy expenditure should also be incorporated in the assessment of nutritional status in kidney disease patients. For research purposes, nitrogen balance studies or metabolic assessment by stable isotopes can provide invaluable physiological information complementing routine nutritional assessment tools. Similarly, a number of more sophisticated tools such as dual energy X-ray absorptiometry or magnetic resonance imaging can provide more precise information on body composition and are primarily used for research purposes. Incorporation of clinical information with practical methods of nutritional assessment is the core of appropriate screening for and assessment of PEW in the clinical setting. More sophisticated methods should be added to these only for research purposes.
Objectives: The aim of the present study was to analyze and correlate muscle strength of the back and front squat with performance in the movements of weightlifting (WLFT) snatch and the clean in CrossFit® practitioners.
Method: Twenty-two adults participated in this study and were divided according to their performance in the snatch and clean movements: stronger (29.6 ± 4.4 years; 80.95 ± 9.57 kg; 12.2 ± 5.8 % body fat; 2.4 ± 0.9 training experience) and weaker (28.5 ± 5.4 years; 79.4 ± 6.8 kg; 13.6 ± 3.5 % body fat; 2.0 ± 1.1 training experience). All volunteers completed one-repetition maximum tests in separate days in the following exercises: back squat, front squat, snatch and the first phase of the clean.
Results: The volunteers classified with a superior performance in the snatch and clean presented a higher strength in the back squat (154.9 ± 20.3 kg vs 132.7 ± 11.6 kg; p = 0.009) and front squat (139.0 ± 14.5 kg vs 116.8 ± 11.3 kg; p = 0.002) as compared with the weaker volunteers. Additionally, there were strong correlations between relative strength in the back squat (r=0.83; r=0.76; p=0.001) and front squat (r=0.73; r=0.83; p=0.001) with the performance in the snatch and clean exercises, respectively.
Conclusions: Therefore, a superior strength in basic exercises, such as back and front squat can contribute to WLFT performance in CrossFit® practitioners.
Este estudo teve por objetivo avaliar aspectos da imagem corporal em uma amostra de pessoas com anorexia nervosa, bulimia nervosa e transtorno alimentar não-especifi cado. A amostra foi composta por 14 voluntárias atendidas pelo Ambulatório de Transtornos Alimentares da Universidade Estadual de Campinas. O Software de Avaliação Perceptiva foi utilizado para avaliar a insatisfação com o corpo. A preocupação com o corpo, checagem e evitação corporal foram avaliadas pelo Body Shape Questionnaire, Body Checking Questionnaire e Body Image Avoidance Questionnaire, respectivamente. A análise descritiva e as correlações entre as medidas mostraram elevados níveis de insatisfação, checagem, evitação e preocupação com o corpo, com associações signifi cantes. Estes achados evidenciaram a importância dos parâmetros investigados na dinâmica dos transtornos alimentares. Conhecer esses componentes da imagem corporal favorece a ampliação das possibilidades de melhor compreender como se organiza a representação mental do corpo dessas pacientes e planejar mais cuidadosamente as intervenções no decurso do tratamento.
The aim of this study was to investigate aspects of body image in a sample of people with anorexia nervosa, bulimia nervosa and eating disorder not otherwise specifi ed. The sample was composed of 14 volunteers, cared for by the Eating Disorders Outpatients Clinic, from Universidade Estadual de Campinas. The Software for Perceptual Assessment (SPA) assesses body dissatisfaction. The variables body concern, checking behavior and avoidance behavior were assessed by the Body Shape Questionnaire, Body Checking Questionnaire and Body Image Avoidance Questionnaire, in this order. The descriptive analysis and correlations indicate high levels of dissatisfaction, checking behavior, avoidance behavior, and concern over the body, with signifi cant associations. These fi ndings showed the importance of the investigated parameters for the dynamic of the disease. Knowing these body image components could expand the possibilities of understanding how these patients organize their body representations and carefully plan interventions during the course of the treatment.
Methods of in vivo body fat estimation are based on simple assumptions about body composition which work reasonably well for men, while estimations in women have been largely extrapolated from the male studies so that women are treated as men with just more of the same fat. Compared to men, fat regulation in women is considerably more elaborate, with more and different sites for storage and a larger proportion of fat distributed to the extremities and in subcutaneous locations. Thus, a ratio of waist-to-hips girth which reflects increasing fatness in men only specifies 2 different extremes of a broader spectrum of possibilities for fat distribution in women. This complicates anthropometric prediction of total fatness and clearly limits the generalisability of any female equations. Anthropometric methods are further confounded by difficulties in the criterion methods against which they are developed. For example, the validity of assumptions about the fractional contributions of bone mineral and body water to fat-free mass and density may not hold through the reproductive cycles. Women athletes involved in weight-bearing or strength training may increase bone mineral content above average values but if they become amenorrhoeic, bone mineral density may fall significantly below average values. Fit premenopausal women distribute fat differently and have a higher bone mineral content than unfit postmenopausal women. Genetic factors which also affect criterion method assumptions in men are superimposed on these additional complications in women. Body fat in female athletes extends across almost the entire range of female fatness, with some of the lowest measurements in distance runners and body builders which fall into the normal male range, but also with some relatively high values in swimmers and strength athletes, which would classify these women as obese by male standards. Thus, total body fat reflects a more complex regulation and has a different meaning to health and performance in women than it does for men. Predictive equations for women athletes should be developed with a view to the specific group and ultimate purpose to which they will be applied.
The Ross (R) plastic caliper scale (y) systematically overestimates the true thickness (x): y = 1.148 x +0.112, r = 0.999. The Harpenden (H) caliper scale was accurate. The jaw pressure of the Ross caliper (Ẋ ± SD = 12.0 ± 0.9 g/mm 2) overestimated the Harpenden pressure (7.95 ± 0.2 g/mm 2), compensating somewhat the scale error of the Ross caliper. For instance, there was practically no difference between calculated fat percentage (16.5 ± 5.1 and 16.8 ± 5.4% for H and R, r = 0.995, n = 30). The McGaw (M) and the Ross plastic calipers gave almost identical results for fat percentage (18.4 ± 4.7 and 18.3 ± 4.7% for M and R, r = 0.993, n = 20). It is thus concluded that the Ross and McGaw plastic adipometers yield valid results.
Because of its noninvasive approach, anthropometry is one of the oldest and most popular methods of estimating body composition. However, this practical approach is often misused and misinterpreted by both clinicians and researchers. This article reviews the major methods for estimating body composition in various populations, with emphasis on anthropometry. Steps that will help clinicians select an appropriate anthropometric equation and reduce errors include using the same measurement procedures described in the original study and making sure the equation is based on a similar sample of 50 to 150 subjects in terms of age, sex, and activity levels.
The effect of excess fat weight and equipment weight on skating performance is unclear because much of the player's skating movement is performed in a gliding position. The purpose of this investigation was to examine the effect of added weight on a player's skating performance in an ice hockey fitness test. During added-weight conditions, the players were slower and had greater anaerobic endurance times. Coaches and players should be concerned about the players' fat weight and equipment weight because they contribute to slower performance times.
The plastic McGaw caliper and the Lange caliper were used to measure the triceps skinfold thickness of both arms of 91 volunteer subjects and of the left arms of 14 obese patients. McGaw caliper values were highly correlated with the Lange caliper values (r = 0.97) but were significantly lower than the Lange caliper values (P less than 0.01). Triceps skinfolds could not be measured by the McGaw caliper on 11 very obese patients, all of whom had Lange triceps skinfold thicknesses greater than 45 mm.
Summary The study was made to assess the order of error and the sources of inaccuracy of anthropometric measurements made by a team of 9 trained observers. Some observers displayed internal inconsistencies in making the measurements, and the variability in overall means due to differences between observers were relatively large. Restricting certain observers to the instruments upon which they show consistency and additional training of these observers, or the use of control charts based on tolerance limits, estimated from pooled variances of intra- and inter-individual variances, or intra-individual variances alone, would reduce the present errors to more reasonable levels.
The estimation of body density from anthropometric variables is often used to measure body composition. The purpose of this report was to review the development of early published equations and follow the transition from population specific equations to generalized equations for adults. The accuracy of population specific equations were improved and refined with the addition of circumference and diameter measures in combination with skinfolds and the use of populations of varied ages and degrees of body fatness. The major weakness of the population specific equations was their inability to account for aging and the non linear relationship between subcutaneous fat and body density. Regression models using the quadratic sum of skinfolds and age have been developed to account for these sources of variation. Cross-validation research has shown that these generalized regression models are accurate for adult males and females varying greatly in age and body fatness.