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... In anthropometry, the most popular ones are the 3-site and 7-site Jackson and Pollock equation devised for men [69], and the Jackson, Pollock, and Ward equation developed for women [70]; regardless of sex, they are commonly abbreviated as JP3 and JP7, respectively. Once body density is obtained, %BF can be computed using the Siri equation [11] or its alternatives developed for specific populations. ...
... The validation study of Smith-Ryan et al. focused on overweight and obese subjects evaluated by the BodyMetrix instrument in conjunction with the JP7 formula [75]. As a reference method, they used Siri's 3C model [11], which relies on measurements of BV and total body water-TBW (kg); BV was determined by ADP and TBW was inferred from BIS. Despite its simplicity, Siri's 3C model is highly appreciated in the literature because it is insensitive to variations in fat-free mass hydration and demonstrates excellent agreement with 4C, 5C [90], and 6C [91] models. ...
Body composition assessment by ultrasonography is a vivid research field. Ultrasound (US) can be used to quantify subcutaneous and visceral fat, to evaluate the quantity and quality of skeletal muscle, and to infer intracellular fat content. This scoping review aimed to summarize recent advancements in subcutaneous fat estimation using US and related applications. A systematic search was conducted on PubMed, MEDLINE, Scopus, Google Scholar, and Web of Science to identify original articles published in English between 1 January 2014 and 20 December 2024. A total of 1869 articles were screened based on their titles and abstracts, and 283 were retrieved for full-text evaluation. Our search and selection strategy resulted in 89 eligible documents. The literature discussed in this review suggests that US is a reliable and valid technique for measuring subcutaneous fat thickness at selected anatomic locations. Standardized measurement protocols enabled accurate subcutaneous adipose tissue (SAT) patterning in various populations (e.g., athletes, children, adults, and patients with anorexia nervosa). Further research is warranted to establish clinically relevant cutoff values. US-derived SAT thicknesses can also provide whole-body fat estimates of fat mass (FM), fat-free mass (FFM), and body fat percentage (%BF). To this end, prediction formulas were developed to ensure agreement with criterion measures given by laboratory techniques, or multicompartment models based on combinations thereof. The resulting assessments of global adiposity were reliable but inaccurate in certain populations (e.g., overweight and obese). Nevertheless, due to its high reliability, US might be used to track changes in body fat content during nutritional and/or lifestyle interventions. Future investigations will be needed to evaluate its accuracy in this respect and to improve the validity of whole-body fat estimation compared to multicompartment models.
... and Brozek(1963) 36 ,Durnin and Rahaman (1967) 39 and Siri (1956) 37 ; for women, two equations byJackson and Pollock (1985) 40 and Siri (1956) 37 were used, described as Eq. 1: SF Jackson and Pollock 3S and Eq. ...
... 1: SF Jackson and Pollock 3S and Eq. 2: SF Jackson and Pollock2 3S and one equation of Jackson, Pollock, andWard (1980) 41 and Siri (1956) 37 , described as SF Jackson, Pollock, and Ward 4S ...
The correct name is: Denise Pires de Carvalho
... Adipose tissue mass is measured by ADP [68], using the non-invasive BodPod system (Cosmed, USA). This system uses whole-body densitometry to determine fat and fat-free mass in an assessment lasting 3-5 minutes. ...
... Adipose tissue mass is measured by ADP [68], using the PeaPod system (Cosmed USA). This system uses whole-body densitometry to determine fat and fat-free mass in an assessment lasting 3-4 minutes. ...
Introduction
Dolutegravir (DTG)-based antiretroviral therapy is the World Health Organization’s preferred first-line regimen for all persons with HIV, including pregnant women. While DTG has been implicated as an obesogen associated with greater weight gain compared to other antiretrovirals, there is a paucity of data in pregnant women and their children. The Obesogenic oRigins of maternal and Child metabolic health Involving Dolutegravir (ORCHID) study is investigating associations between DTG, weight gain, and metabolic outcomes in the context of HIV.
Materials & methods
ORCHID is a prospective observational study taking place in Cape Town, South Africa (NCT 04991402). A total of 1920 pregnant women with and without HIV infection are being followed from ≤18 weeks gestational age to 24 months postpartum with their children. Participants attend eleven study visits: 3 antenatal, delivery, and 7 postnatal visits. Several embedded sub-studies address specific scientific aims. Primary outcome measurements in mothers include anthropometry, blood pressure, body composition, dysglycemia, insulin resistance (IR), and dyslipidemia. Other maternal measures include demographics, resting energy expenditure, viral load, physical activity, dietary intake, hepatic steatosis, and repository specimens. Sub-study measurements include markers of adipose inflammation, gut integrity, and satiety/hunger, subcutaneous adipose tissue morphology and mitochondrial function, and metabolomics. Primary outcome measurements in children include anthropometry, adipose tissue mass, dysglycemia, IR, and dyslipidemia. Other variables include fetal growth, birth outcomes, medical/breastfeeding history, caloric intake, neurodevelopment, and repository specimens. Sub-study measurements include metabolites/lipid subspecies in umbilical cord blood, as well as breast milk composition and DTG exposure.
Discussion
ORCHID will play a pivotal role in defining obesogenic mechanisms and clinical consequences of DTG use in pregnancy in women with HIV and their children. It will provide insights into metabolic disease risk reduction in the context of HIV/DTG, identify intervention targets, and inform public health approaches to diminish chronic metabolic co-morbidities for women and children.
... 1 The Siri equation 19 was used to convert body density into body fat percentage. ...
OBJECTIVE: The objective of this study was to compare bioelectrical impedance analysis and skinfold measurements for the estimation of body fat in adults. METHODS: We analyzed data from 292 adult participants enrolled in a cross-sectional population-based study. Four skinfold measurements were performed, and body fat percentage was estimated using the Petroski formula. Bioelectrical impedance analysis was performed using a tetrapolar electrical bioimpedance device. The measurements were compared using Student's t-test, Robinson's coefficient of agreement, Cronbach's alpha, and linear regression models (slope and intercept). RESULTS: The mean percentage of body fat estimated by skinfold measurements was higher compared to bioelectrical impedance analysis (29.0 vs. 27.9; p<0.001), but the agreement between the methods is good (alpha=0.88; Robinson's coefficient of agreement=0.91). Linear regression models showed a good correlation (r2=0.69). Bland-Altman analysis showed a mean difference of −1.02 (−1.54 vs. −0.50) between the two techniques. The agreement was better in women, those aged 20-39 years, those with a body mass index<25, and those with a waist-to-height ratio<50. CONCLUSION: The two methods showed a good agreement between the mean values of body fat percentage and can be used in population studies. However, their results should be considered with caution in men, people aged 40 years and older, overweight people, and those with a waist-to-height ratio≥50.
... The percentage of FM was estimated using a calibrated skinfold calliper (Harpenden; Baty International, United Kingdom) following the procedures suggested by the American College of Sports Medicine [30]. Body density was predicted using the Jackson & Pollock skinfold thickness equation [31] and the Siri equation was employed to convert the estimated body density to the percentage of FM [32]. ...
Purpose
This study aimed to investigate the time course of β-endorphin (β-EDP) levels in healthy males following an acute exercise, while considering their age and physical fitness (PF) level.
Methods
Participants (N = 29, 20–65 years) were categorized in good PF young adult (YA1), excellent PF young adult (YA2), and excellent PF middle-aged adult (MA) group, depending on peak oxygen uptake and age. They underwent a maximal incremental cycling test, with blood samples collected at baseline (T0), 15 min (T1), and 24 h post-exercise (T2). Serum β-EDP levels were measured using an ELISA kit.
Results
Significant increases in β-EDP levels were observed from T0 to T1 in all enrolled subjects. In YA1, levels rose from 170.1 to 202.5 pg/ml (p < 0.001), in YA2 from 188.4 to 230.3 pg/ml (p < 0.05), and in MA level increased from 153 to 189.3 pg/ml (p < 0.01). YA2 showed higher levels of β-EDP than MA in any time point (p < 0.05). All groups displayed a significant decrease of β-EDP from T1 to T2. Comparison between groups revealed that age significantly influenced baseline β-EDP levels, with notable differences between young and middle-aged individuals. Noteworthy, MA with excellent PF presented similar β-EDP levels to young with good PF.
Conclusion
Acute exercise triggers a notable but transient elevation of serum β-EDP levels in both young and middle-aged adults, with the latter exhibiting lower baseline levels. Additionally, our findings suggest that age may have a greater influence on β-EDP secretion, both at rest and after physical exercise compared to PF level.
... 14 ). Body density was estimated using the Durnin and Womersley method 15 and FM was calculated using the Siri equation 16 . The threshold for low FFMI was defined as FFMI<16 kg/m 2 for men and FFMI<15 kg/m 2 for women 17 . ...
... Body mass index was calculated as body weight (kg) divided by height squared (m 2 ). Body composition (i.e., FM, FFM, bone mineral content, and density) was determined using dual X-ray absorptiometry (DXA, QDR4500A scanner, Hologic, Waltham, MA, USA), body protein content was calculated from FFM with the assumption of a protein content of 19.4% (Siri 1993), and total body water (kg and percent of body weight) was assessed via multifrequency bioelectrical impedance (Tanita MC-780 Tanita Corporation, Tokyo, Japan). The ratio of the change in FFM to the change in body weight ( FFM/ body weight) between conditions was calculated. ...
Athletes may engage in weight cycling—successive episodes of weight loss and weight (re)gain—for performance reasons, but risk metabolic adaptations and regaining more fat that was lost (fat overshoot). This study aimed to assess the influence of a complete weight cycling episode on body composition, thermoregulation, and metabolism in athletes, considering sex and the type of sport practiced. Forty-eight athletes (28 males, 20 females) engaged in combat (n = 23), strength (n = 12), or endurance (n = 13) sports were examined under three experimental conditions (weight maintenance, weight loss, weight (re)gain) during a weight cycling episode using their habitual strategies. Body composition (dual-energy X-ray absorptiometry), core body temperature (telemetric temperature sensor), energy expenditure and substrate oxidation at rest and during moderate exercise (indirect calorimetry), and energy intake (48 h food record) were assessed. Overall, athletes lost 4.4 ± 2.3% body weight, 12.2 ± 10.6% fat mass, and 2.6 ± 2.3% fat-free mass (p < 0.001). All variables returned to baseline values during the regain period, and a higher fat mass regain was observed in endurance than combat athletes (p < 0.01). During weight loss, a transient increase in lipid and decrease in carbohydrate oxidation occurred at rest and during exercise (p < 0.001). Energy expenditure and core body temperature remained unchanged across the three experimental conditions, and no specific sex effect was observed. Overall, no apparent body weight nor fat overshoot was observed in athletes after a complete weight cycling episode. Nonetheless, the greater fat mass gain in endurance, compared with combat athletes, highlights a need for further specific long-term studies in this population. Clinical Trial registration: NCT04107545.
... Body mass was measured using the integrated scale, and body volume was measured while the participant was sitting inside the BOD POD chamber. Body density calculated from body weight and volume and measured thoracic gas volume are used in the densitometric equation by Siri [26] to calculate %FM. ...
Background: The period following childbirth is marked by dynamic changes in maternal physiology and the growth trajectory of the newborn. We aimed to elucidate the changes and associations in body composition of infants and their mothers during the first year postpartum. Methods: This pilot study assessed infant body composition using the PEA POD air displacement plethysmography (ADP) system (birth–6 months) and deuterium dilution (9–12 months). Maternal body composition was assessed using the BOD POD ADP system at 12 months postpartum. Mothers were grouped by prepregnancy body mass index (BMI) <25 kg/m² (lean) or ≥25 kg/m² (overweight/obese: OW/OB), and data were analysed using linear regression. Results: Twenty-nine infant–mother pairs were assessed. Infant percent fat mass (%FM) increased from birth to 6 months (9.3% vs. 24.2%; p < 0.001) and then gradually declined. At birth and 3 months, %FM was significantly higher in infants born to OW/OB mothers compared to their lean counterparts. A significant positive association (β = 0.3; p = 0.040) was observed between maternal %FM and infant %FM at 1 year post-delivery after controlling for the mother’s prepregnancy BMI. Conclusions: Infants born to OW/OB mothers have increased %FM at birth and 3 months, which may have consequences for their health throughout childhood and into adulthood. Moreover, maternal prepregnancy BMI is a significant predictor of maternal postpartum weight status and body composition and impacts the relationship between maternal and infant body composition at 12 months postpartum. While the findings of our pilot study underscore the importance of encouraging women of childbearing age to maintain a healthy BMI before conception, further research is needed to substantiate these results.
... For males, these locations were the chest, abdominal area, and thigh, while for females, they were the triceps, suprailiac area, and thigh. The skinfold thickness data were used to estimate body fat percentage (%BF), applying equations from prior studies [52,53]. ...
Background
Being overweight contributes to increased health risks, particularly cardiac and metabolic disorders, in young adult women. This study compares the effects of Retro Walking (RW) and Forward Walking (FW) on cardiac autonomic function, cardiorespiratory fitness, and body composition in overweight female university students.
Methods
A randomized-controlled trial divided 30 overweight female students into RW, FW, and control groups. Cardiac autonomic function was assessed using Heart Rate Variability (HRV), cardiorespiratory fitness via VO2max and Heart Rate Recovery (HRR), and body composition through Body Mass Index (BMI), waist circumference (WC), and hip circumference (HC).
Results
RW demonstrated significant improvements in cardiac autonomic function, indicated by increases in SDNN (p < 0.001), RMSSD (p < 0.001), and pNN50 (p < 0.001), as well as higher HF power (p < 0.001), suggesting enhanced vagal tone and potential reductions in sympathetic activity. Both RW and FW improved cardiorespiratory fitness, with RW having a more pronounced effect on VO2max (p < 0.001) and immediate HRR (p < 0.001), although no significant difference was found between groups in post hoc analysis. RW led to greater reductions in BMI (p = 0.002), WC (p < 0.001), and HC (p < 0.001) compared to FW and control groups.
Conclusion
RW emerges as a beneficial exercise modality for managing obesity-related health risks in overweight young adult women, providing superior improvements in cardiac autonomic function, cardiorespiratory fitness, and body composition over traditional FW.
... Body density was calculated from the BOD POD software. Body fat percentage was calculated using the Siri equation and FM and FFM subsequently estimated (18). Underweight was defined as Body Mass Index (BMI) <18.5 kg/m 2 . ...
Purpose
The purpose was to evaluate the individual and combined use of the Low Energy Availability in Females Questionnaire (LEAF-Q) and the Brief Eating Disorder in Athletes Questionnaire (BEDA-Q) to detect clinical indicators associated with Relative Energy Deficiency in Sport (REDs).
Methods
In this cross-sectional study, 50 female endurance athletes training ≥4x/week completed the LEAF-Q and BEDA-Q and were assessed for presence of selected REDs indicators. Athletes meeting the criteria for mild or more severe REDs severity/risk according to the International Olympic Committee REDs Clinical Assessment Tool Version 2 (IOC REDs CAT2) were classified as REDs cases. Diagnostic properties of the German versions of the LEAF-Q and BEDA-Q were assessed at different cut-offs using receiver operating characteristics calculations.
Results
Fourteen (28%) athletes were classified as REDs cases. The LEAF-Q had a sensitivity of 79% and a specificity of 50%, with a positive predictive value (PPV) of 38% and negative predictive value (NPV) of 86%. For detection of disordered eating behaviour/eating disorder (DE/ED), the BEDA-Q showed a sensitivity and specificity of 71% and 76%, respectively, with a PPV of 68% and NPV of 79%. Out of 14 REDs cases, nine (64%) scored positive in the LEAF-Q and BEDA-Q. Two athletes (14%) scored positive only in the LEAF-Q and one athlete scored positive only in the BEDA-Q. Two REDs cases remained undetected by both questionnaires.
Conclusions
Among German female endurance athletes, the LEAF-Q and BEDA-Q are good screening tools to detect REDs cases with mild or more severe severity/risk as classified according to the IOC REDs CAT2. Further clinical assessments should be initiated when athletes score positive in at least one of the questionnaires.
... Body fat percentage (BF%) values were produced using the Siri equation [23]. ...
Background/Objectives: Adherence to sports-specific nutritional guidelines can help optimize athlete performance and health. However, adolescent athletes may not have adequate nutrition knowledge and understanding of specific nutritional requirements. The objective of the current study was to examine the nutrition knowledge and perceived dietary requirements of adolescent athletes. Methods: Male (n = 29, age: 15.7 ± 1.3 yrs.; height: 178.9 ± 8.3 cm; body mass: 74.7 ± 17.2 kg; body fat %: 13.9 ± 7.9%) and female (n = 15, age: 16.5 ± 1.4 yrs.; height: 169.9 ± 6.5 cm; body mass: 63.3 ± 4.5 kg; body fat %: 23.7 ± 3.8%) secondary school student-athletes completed body composition testing (hydrostatic weighing) and electronic surveys (Abridged Sports Nutrition Knowledge Questionnaire (ASNKQ); self-perception of dietary energy and macronutrient requirements). Results: Athletes demonstrated poor sports nutrition knowledge, with no differences observed between sexes for the number of questions answered correctly (males: 45.1 ± 9.8% vs. females: 43.1 ± 12.7%; p = 0.57). No relationships were observed between ASNKQ scores and body composition parameters or between ASNKQ scores and self-reported perception of dietary energy and macronutrient requirements (p > 0.05). Athletes self-reported a lower perceived energy (−560 ± 1272 kcal/d; p = 0.014) and carbohydrate intake (−73 ± 376 g/d; p = 0.014) requirement compared to calculated nutritional recommendations. Athletes self-reported a higher perceived protein intake (263 ± 586 g/d; p = 0.026) requirement compared to calculated nutritional requirements. Conclusions: The current sample of adolescent athletes from the secondary school level appears to have a poor level of sports nutrition knowledge and understanding of energy and macronutrient requirements.
... Both the PEA POD and BOD POD have high accuracy and precision and are feasible and safe for assessing body composition in infants and children, respectively [21,22]. Siri equation was used to translate whole-body density to percent body fat [23,24]. ...
... The body density was estimated using gender specific regression equations from the sum of the skinfold measurements outlined by Petersen, 2003 [8]. Body fat percentages were estimated from the body density using Siri's equation [13]. The root means square error, related to interrater reliability, for the calculation of subcutaneous BF% has been found to be 4.6% [8]. ...
Background
Serum glucose, cholesterol, triglycerides and high-density lipoproteins (HDL) are established cardiovascular disease (CVD) markers, however accessibility to these markers is less in individuals from low-middle income countries. The non-invasive CVD risk marker especially skinfold measured fat percentages are less explored for its relevance with established serum biochemistry markers.
Methods
A cross-sectional study was conducted in 70 sedentary office workers (aged 30–40 years) who were healthy. Peripheral fat percentages were estimated from four skinfold thickness measurements and biochemistry markers were measured and analysed using standard laboratory measurements. Blood pressure was also measured. Multivariate linear regression models were drawn to establish the association between the non-invasive and invasive CVD risk markers.
Results
The skinfold measured fat percentage was negatively associated with the HDL (coefficient β = -0.15, standard error SE = 0.07, p < 0.05). No significant relation between the other biochemistry parameters with the skinfold thickness. Age and BMI were found to be mediating the above relationship.
Conclusions
Skinfold thickness derived fat percentage is associated with the few of the CVD markers (especially HDL). Age and BMI are crucial mediating factors for the fat measurement. Skinfold measurements could be included as part of routine primary care screening for CVD risk, alongside invasive biochemistry parameters.
... Although it does not need undressing or physical activity, total body water (TBW) is simple to assess, but its applicability to obese people is limited. The primary premise is that fat-free mass (FFM) is calculated from TBW using an average of 73% presumptive TBW; however, this percentage might vary from 67% to 80% (Siri, 1993). Furthermore, extracellular fluid from adipose tissue contains 15% to 30% of TBW, and this percentage rises with increased adiposity. ...
The present research paper's goal is to examine the most recent, accurate, and useful techniques for measuring human body composition. The techniques to measure Human body composition are continuously being met by emerging data results. Key efforts include the usage of imaging to help explain ectopic fat depots, quantifiable magnetic resonance for entire body water, fat and lean tissue measurement, and multi-divisional and multi-repetitive bioelectrical impedance analysis. Assessments of total body fat, fat-free mass, total body water, bone mineral content, cellular water, visceral, subcutaneous, skeletal muscle, major organs, and abnormal body fat depots are all approved using the relevant methodologies. The need for a method that generates data on biological and metabolic processes is constant. Clinicians and scientists can measure a variety of body elements and, observe changes in health and disease with implications for understanding the effectiveness of nutritional and medical disruptions, assessment, deterrence, and treatment in clinical settings. This is made possible by the wide range of measurable characteristics, analytical techniques, and designated total body composition models. The increased requirement to comprehend health risk precursors starting before conception has left a gap in the proper assessment techniques, with implementation starting during gestation, or foetal development.
... The subject used tight fitting shorts, as well as a swim cap to compress the hair. In addition to weight and body volume, the equipment provides estimates of total fat mass and fat-free mass percentages using Siri's equation (34). Knee extensor and flexor torque signals were recorded after gravity correction and sampled at 100 Hz using the dynamometer's software (Biodex, System 4 Pro TM , Biodex Medical Systems, New York, NY, USA). ...
... 4.95 body density -4.5x 100 (Siri, 1993). During measurement, the ultrasound probe was applied perpendicular to the skinfold and obliquely (chest) or parallel (abdomen and thigh) to the longitudinal axis. ...
Purpose: The present study aimed to compare final partial range of motion (final pROM) vs. full range of motion (fROM) in muscle hypertrophy and maximal strength development in physically active young men. Methods: Ten physically active young men (age=22.90±2.47 years; body mass=83.85±11.67 kg; height=176.30±6.22 cm) participated in a randomized, intra-subject experimental design in which RT was performed using the upper- and lower-limbs with final pROM or fROM three times per week for six weeks. For all subjects, an arm or thigh was randomly selected and assigned for the final pROM condition, and the contralateral limb for the fROM condition. The subjects performed three sets of 12 repetitions at 60% of one-repetition maximum (1-RM), with two-minute rest interval between the sets and between limbs. The muscle hypertrophy of the elbow flexors and the knee extensors and the 1-RM test in the specific ROM that has been trained was measured before and after the intervention. An analysis of covariance was used to compare the different conditions on muscle hypertrophy and the maximal strength development. Results: The results showed that there was no statistically significant difference between the conditions for elbow flexors muscle hypertrophy (p=0.920; Cohen’s d=0.046) and knee extensors muscle hypertrophy (p=0.291; Cohen’s d=0.152). Similarly, there was no statistically significant difference between the conditions for 1-RM of the arm (p=0.161; Cohen’s d=0.898) and 1-RM of the thigh (p=0.276; Cohen’s d=0.533). Conclusions: Therefore, these findings suggest that there was no statistically significant difference between the different ROM, however, the moderate-large effect size (leg=0.533 and arm=0.898) in favor of final pROM in the maximal strength development, may indicate a potential direction for future research in physically active young men.
... Body density was obtained using the sex-and age-specific Durnin and Womersley equations [29]. Percentage of body fat (BF) was calculated through Siri's formula [30]: BF = (4.95 / density -4.50) × 100. ...
Background/Objectives
Anxiety and depression are common mental disorders worldwide, in particular in people with obesity. Adherence to the Mediterranean diet has been found beneficial for the prevention of anxiety and depression in the general population. We aimed to evaluate this association in a large cohort of people with obesity.
Subjects/Methods
A cross-sectional study of 4957 patients with obesity (63.1% women, median age 49 years, IQR 40–58 years and BMI 33.6 kg/m², IQR 31.6–36.9 kg/m²) was carried out. Clinical history, anthropometric measurements and lifestyle-related information were investigated. A 14-item MEDAS questionnaire was used to assess adherence to the Mediterranean diet. The 20-item STAI2 questionnaire and the 24-item QD questionnaire were used to assess the presence of anxious and depressive symptoms, respectively. Clinical cases of anxiety and depression were identified among patients with a physician-made diagnosis of anxiety and depression or with STAI2 and QD score ≥95th percentiles of reference population.
Results
Overall, 11.9% of participants were positive for anxiety and 11% for depression. Multivariate linear regression models showed a decrease in STAI2 and QD scores of 0.18 points (95%CI: −0.33, −0.03) and 0.10 points (95%CI: −0.16, −0.03), respectively, for each 1-point increase in MEDAS score. The multivariate logistic regression model showed a 7% reduction in the odds of anxiety and depression for each 1-point MEDAS increase (OR = 0.93, 95%CI: 0.89, 0.99; OR = 0.93, 95%CI: 0.88, 0.98).
Conclusions
Mediterranean diet is associated with a lower risk of anxiety and depression in people with obesity. Longitudinal studies are needed to determine causality.
... Participants' body composition was assessed using a threecompartment model, including total-body water derived from bioelectrical impedance analysis (seca 514, seca, USA) and body density via BodPod (COSMED, USA). The following formulas were used to assess fat mass (FM) and fat-free mass (FFM), where body density was measured in kg/L, total-body water in L, and body mass in kg (Siri, 1993): ...
The purpose of this study was to examine the skeletal muscle hypertrophic, architectural, and performance‐related adaptations in response to volume‐matched, total‐body flywheel versus traditional resistance training in a randomized, non‐exercise controlled study in physically active young adults. Thirty‐one healthy young adults (24 ± 3 y) were randomized to 10 weeks of traditional resistance training (TRT; n = 7F/5M), flywheel training (FWRT; n = 7F/4M), or a habitual activity control (CON; n = 5F/3M). Maximal voluntary isometric torque (MVIT), one repetition‐maximum (1RM) for the free weight squat and bench press, three repetition work maximum (3Wmax) for the flywheel squat and bench press, countermovement jump height, and broad jump distance, as well as site‐specific muscle hypertrophy, fascicle length (FL), and pennation angle, were measured. Both TRT and FWRT increased MVIT (p ≤ 0.021) and FFM (p ≤ 0.032) compared to CON. However, TRT promoted superior improvements in free weight squat and bench 1RM (p < 0.001), and FWRT improved flywheel 3Wmax squat and bench (p < 0.001). FWRT increased the FL and cross‐sectional area of the distal VL, countermovement jump height, and broad jump distance (p ≤ 0.048), whereas TRT increased the pennation angle and cross‐sectional area of the proximal VL. Therefore, 10 weeks of volume‐matched, total‐body traditional, and flywheel resistance training similarly increased maximal isometric strength and fat‐free mass. However, FWRT promoted unique skeletal muscle architectural adaptations that likely contributed to region‐specific VL hypertrophy and jump performance improvements. Thus, FWRT provides a novel training stimulus that promotes architectural adaptations that support improved athletic performance in a manner that is not provided by traditional resistance exercise training.
... The skin folds (SFs) were measured with a Sanny® scientific adipometer, precisely at 1 mm on the right side of the body at four sites (subscapular, triceps, supra-iliac and medial calf). The equation for the prediction of body density (BD) proposed by Petroski (1995) was applied, and for the calculation of fat percentage, the Siri Equation (Siri, 1961) was used.Upper limb strength was measured by a hand grip test with a JAMAR Dynamometer, following the ASHT (Araujo, 2003) guidelines; the participants were evaluated in a seated position with the elbow at 90° without moving it, and the appliance was pressed as hard as possible at the signal of the evaluator. To evaluate the strength and resistance of the lower limbs, the sit-and-stand test was performed for 30 seconds, during which the patient sat in a chair, arms crossed against the chest, and at the evaluator's signal, the patient reached and sat down completely for a maximum of 30 seconds (Rikli & Jones, 1999). ...
This study examines the impact of different physical exercise programs on health variables in elderly individuals. A total of 60 participants were assigned to four groups: resistance training in open-air gyms (GT1, n = 17), aerobic and localized exercises (GT2, n = 11), resistance training in traditional gyms (GT3, n = 17), and a control group (CG, n = 15). Anthropometric, cardiovascular, metabolic, and strength parameters were measured before and after 16-week intervention. The GT1 showed a small effect (Cohen d effect size) on fat percentage, waist-rip ratio (WHR), and upper limp strength (ULS) and a medium effect on lower limb strength (LLS). For the GT2, there was a large effect on the LLS. For the GT3, there was a medium effect on the ULS and a large effect on the LLS. There was a small effect on glycemia in the GT1, a medium effect on glycemia and triglycerides in the GT2, a small effect on total cholesterol in the GT3, and a large effect on glycemia in the CG, where the glucose levels were increased. There were large effects on SBP in the GT2; small effects on SBP, DBP, and HR in the GT3; and small effects on SBP and HR in the CG. The TG, LLS, and ULS variables differed the most for each type of exercise. The three methods proved to be efficient, but some may be preferred over the others based on the patients' health conditions, objectives, or characteristics at the time when the physician assigned them to the program.
... Participants visited the laboratory on 3 nonconsecutive days (minimum of 48-h and maximum of 1-wk interval between visits). On the first visit, body fat was determined, [12][13][14] and participants were familiarized with the experimental procedures. On the second visit, participants were, again, familiarized with the experimental procedures. ...
Purpose : To determine the effects of repeated Brazilian jiujitsu (BJJ) matches on neuromuscular fatigue in forearm-flexor and knee-extensor muscles. Methods : Twelve BJJ athletes (8 men and 4 women) performed a simulated BJJ tournament composed of four 8-minute matches interspersed by 16-minute intervals. Neuromuscular fatigue was assessed via prematch to postmatch(es) reductions in maximal voluntary isometric contraction (MVIC), voluntary activation, and potentiated twitch force (Ptw pot ) in the forearm-flexor and knee-extensor muscles. Results : The MVIC of the knee extensors and forearm flexors reduced from prematch 1 to postmatch 2 and remained suppressed until postmatch 4 ( P < .034). The voluntary activation of the knee extensors declined only after match 4, whereas the voluntary activation of the forearm flexors did not change throughout the matches ( P = .102). Ptw pot of knee extensors decreased from prematch 1 to postmatch 1 ( P < .001) and remained reduced until postmatch 4 ( P < .001). Ptw pot of the forearm flexors reduced after every match ( P < .010), with complete recovery occurring only before the second match ( P = .99). The magnitude of the prematch-to-postmatch reduction in Ptw pot was lower in knee extensors than in forearm flexors ( P = .044). Conclusions : Repeated BJJ matches induced neuromuscular fatigue, mainly due to impairments in muscle contractile function (ie, peripheral fatigue). The time between BJJ matches seems to be insufficient to allow complete recovery of neuromuscular function, which may influence performance during subsequent matches.
... Thoracic gas volume was predicted based on equations included in the Bod Pod software. From these data, body fat-free mass, fat mass, and fat percentage were calculated as described by Siri 33 . Subsequently, skeletal muscle NAD + and NADH concentrations were determined under normal perfusion and during ischemia using the new 31 P-MRS DEMz sequence as described under the MRS acquisition protocol. ...
NADH and NAD⁺ act as electron donors and acceptors and NAD⁺ was shown to stimulate mitochondrial biogenesis and metabolic health. We here develop a non-invasive Phosphorous Magnetic Resonance Spectroscopy (³¹P-MRS) method to quantify these metabolites in human skeletal muscle on a clinical 3 T MRI scanner. This new MR-sequence enables NADH and NAD+ quantification by suppressing α-ATP signal, normally overlapping with NADH and NAD⁺. The sequence is based on a double spin echo in combination with a modified z-Filter achieving strong α-ATP suppression with little effect on NAD⁺ and NADH. Here we test and validate it in phantoms and in humans by measuring reproducibility and detecting a physiological decrease in NAD⁺ and increase in NADH induced by ischemia. Furthermore, the ³¹P-MRS outcomes are compared to analysis in biopsies. Additionally, we show higher NAD⁺ and lower NADH content in physically active older adults compared to sedentary individuals, reflecting increased metabolic health.
... Isotope enrichment in the urine samples was analyzed with isotope ratio mass spectrometry. A hydration fraction of fat-free mass of 0.73 was applied to determine the total amount of fat-free mass, fat mass, and subsequently, body fat percentage [16]. ...
Background
Monitoring health-related physical fitness (HRPF) may benefit proactive Inflammatory Bowel Disease (IBD) management. However, knowledge regarding HRPF in patients with IBD is limited and gold standard tests are impractical for widespread use, necessitating simpler methods.
Aim
This study evaluated the criterion validity of screening tools and field-based tests compared to gold standard tests for HRPF in patients with IBD.
Methods
Adult patients with IBD completed screening tools, field-based tests, and gold standard tests for HRPF. Criterion validity was examined through (intraclass) correlation coefficients and Bland–Altman plots. Predictive capacity of the screening tools was examined with receiver operating curve analysis.
Results
Among 53 included patients, screening tools demonstrated poor-to-moderate validity compared to the cardiopulmonary exercise test (CPET) for cardiorespiratory fitness. Very strong correlations were found for four-site skinfold thickness and multi-frequency bioimpedance analysis (BIA) with deuterium oxide dilution for body fat percentage (ICC = 0.90, ICC = 0.93), and between the steep ramp test and CPET (r = 0.95) for cardiorespiratory fitness. The steep ramp test also correlated strongly with isokinetic quadriceps (r > 0.75) and hamstring (r > 0.74) strength. Hand-held dynamometry and the sit-to-stand test showed strong correlations with hamstring strength (r > 0.80, r > 0.76). Negligible correlations were found for field-based tests compared to isokinetic quadriceps and hamstring endurance.
Conclusions
Four-site skinfold thickness and BIA showed good agreement with the gold standard for body fat measurement. The steep ramp test demonstrated strong correlations with the gold standard tests for cardiorespiratory fitness and quadriceps and hamstring strength, while hand-held dynamometry and the sit-to-stand test showed strong correlations with hamstring strength.
... 33 Predictive equations may also include assessments of FM and FFM independently estimated using technologies such as air displacement plethysmography (ADP) or bioelectrical impedance analysis (BIA) (eg, the Siri or Nelson equations). 34,35 However, many predictive energy equations may not be suitable for use in patient cohorts that do not meet the inherent assumptions underlying the components of these predictive equations, such as in MND. 36 ...
Objective
To map the international methods used to measure energy expenditure of adults living with motor neuron disease (MND) and to highlight discrepancies when indicating hypermetabolism in the MND literature.
Background
A decline in the nutritional status of patients is associated with exacerbated weight loss and shortened survival. Assessments of energy expenditure, using a variety of methods, are important to ensure an adequate energy intake to prevent malnutrition-associated weight loss. Assessments of energy expenditure are also commonly used to indicate hypermetabolism in MND, although these approaches may not be optimal.
Methods
A protocol based on the Preferred Reporting Items for Systematic Reviews and Meta-analyses extension for Scoping Reviews Guidelines was developed. Three electronic databases (Medline [Ovid], CINAHL [EBSCO], and Web of Science) were exhaustively searched. Identified publications were systematically screened according to predefined PICOS eligibility criteria. The primary outcome was the identification of methods used to measure energy expenditure in MND. The secondary outcome was the identification of applications of energy expenditure assessments to indicate hypermetabolism in MND.
Results
Thirty-two observational primary research publications were identified. Thirteen (40.6%) were longitudinal in design, with data on repeated measurements of energy expenditure presented in 3 (9.4%). Thirteen (40.6%) were case-control studies, of which 11 use a matched control group. Pulmonary function was used to assess eligibility in 10 publications. Energy expenditure was measured using indirect calorimetry (IC) in 31 studies. Discrepancies in the durations of fasted, measurement, and washout periods were observed. Of all included publications, 50% used assessments of resting energy expenditure to identify hypermetabolism. Bioelectrical impedance analysis was used to assess body composition alongside energy expenditure in 93.8% of publications.
Conclusions
Resting energy expenditure is most frequently measured using an open-circuit IC system. However, there is a lack of a standardized, validated protocol for the conduct and reporting of IC and metabolic status in patients with MND.
... Body volume measurements were taken in duplicate and repeated if measures were not within 150 mL of each other (15). Body density was calculated as mass/body volume, and body fat percentage was calculated by using Siri's formula (46). Body mass index (BMI) was calculated as kg body mass divided by height in meters squared. ...
... En cuanto al IMC/E, este se clasifica como peso bajo cuando es -2 DE de la media; sobrepeso, es mayor de 1 DE de la media, y obesidad por arriba de 2 DE de la media (17) . Mediante la aplicación de la fórmula de Siri (18) [(4,95/DC) -4,5] x 100, se obtuvo el porcentaje de grasa corporal (GC) previa estimación de la densidad corporal (DC) propuesta por Brook (19) , con la suma de cuatro pliegues cutáneos (plicómetro Lange) con una resolución de 1 mm: tricipital, subescapular, suprailíaco y bicipital (DC niños = 1,1690-0,0788 log10 ∑ pliegues; DC niñas = 1,2063-0,0999 log10 ∑ pliegues) (20) . La grasa total (GT) en kilogramos se calculó de la siguiente manera: GT = peso x %GC/100. ...
Objective: To learn about and compare breastfeeding practices, complementary feeding and the nutritional status of preschoolers attending various child development centers in a municipality of Mexico City. Materials and methods: An analytical cross-sectional study which analyzed a sample of 444 preschoolers who underwent anthropometric measurements and hemoglobin determination. Additionally, information on breastfeeding and complementary feeding practices was gathered from mothers. The children were categorized into two age groups (13 to 59 months and 13 to 80 months). Results: The average age was 48.4 months, with 90 % having received breastfeeding for an average of 7.7 months and 63 % having started complementary feeding before six months of age. Significant linear correlations were observed in height-for-age (r = 0.88) and weight-for-age (r = 0.72), and 6.5 % exhibited stunting. According to the nutritional status by body mass index-for-age (BMI-for-age), 3.8 % were classified as underweight, 66.0 % as normal weight, 22.4 % as overweight and 7.8 % as obese. The distribution of these categories was consistent across genders (p = 0.90). Moreover, 13.0 % were classified as at risk of malnutrition based on upper arm circumference. Girls exhibited higher percentages of body fat (BF) (p = 0.008) and total fat (TF) (p = 0.01); 4 % of the children presented anemia, being more prevalent in girls (p = 0.02). There was an average annual weight gain of 2.3 kg across age categories, except for those over six years old, who averaged 11.36 kg. Conclusions: Malnutrition is a growing public health problem. Preschool age is the ideal stage to carry out interventions that stimulate and promote healthy dietary habits and physical activity. Prolonged exclusive breastfeeding for at least six months is crucial for newborns and infants. In conclusion, it is imperative to refrain from using breastmilk substitutes and to delay the introduction of complementary feeding before this period.
... The density calculation proposed by (Jackson & Pollock, 1978) and (Jackson et al., 1980) was applied (7 folds for men and 3 folds for women). After calculating body density, the Siri formula was used to obtain the fat percentage (Jackson et al., 1980;Jackson & Pollock, 1978;Siri, 1956). In addition, the present study measured the waist-to-hip ratio (WHR) by wrapping a flexible measuring tape around the narrowest part of the athlete's waist and recording the measurement, then measuring around the widest part of their hips. ...
981-Retos, número 60, 2024 (noviembre) Evaluation of the BJJFitness test: differences between competitors and non-competitors in Brazilian jiujitsu Evaluación del test BJJFitness: diferencias entre competidores y no competidores en jiujitsu brasileño Avaliação do teste BJJFitness: diferenças entre competidores e não competidores em jiujitsu brasileiro Abstract. This study introduces the BJJFitness Test, a novel tool designed to evaluate the physical and technical performance of Brazilian JiuJitsu (BJJ) practitioners, distinguishing between competitors and non-competitors. The test demonstrated high internal consistency (Cronbach's alpha = 0.992) and strong test-retest reliability (ICC = 0.894). Key variables such as resting heart rate, heart rate during the test, number of takedowns, and rate of perceived exertion (RPE) were critical in differentiating the two groups. Competitors exhibited superior cardiovascular fitness, technical proficiency, and lower perceived exertion compared to non-competitors. The BJJFitness Test mimics real-match conditions, providing a practical and comprehensive assessment method that reflects the unique demands of BJJ. These findings underscore the importance of specific conditioning and technical skills for competitive success in BJJ. The study also highlights the potential of the BJJFitness Test as a valuable tool for coaches and athletes to identify strengths and areas for improvement, guiding targeted training interventions. Resumen. Este estudio presenta el Test BJJFitness, una herramienta novedosa diseñada para evaluar el rendimiento físico y técnico de los practicantes de JiuJitsu Brasileño (BJJ), diferenciando entre competidores y no competidores. El test demostró una alta consistencia interna (alpha de Cronbach = 0.992) y una fuerte fiabilidad test-retest (ICC = 0.894). Variables clave como la frecuencia cardíaca en reposo, la frecuencia cardíaca durante el test, el número de derribos y la tasa de esfuerzo percibido (RPE) fueron críticas para diferenciar los dos grupos. Los competidores mostraron una mayor aptitud cardiovascular, competencia técnica y una menor percepción del es-fuerzo en comparación con los no competidores. El Test BJJFitness imita las condiciones reales de los combates, proporcionando un método de evaluación práctico y completo que refleja las demandas únicas del BJJ. Estos hallazgos subrayan la importancia del acondi-cionamiento específico y las habilidades técnicas para el éxito competitivo en el BJJ. El estudio también destaca el potencial del Test BJJFitness como una herramienta valiosa para entrenadores y atletas para identificar fortalezas y áreas de mejora, guiando intervenciones de entrenamiento dirigidas. Palabras clave: evaluación fisiológica; capacidad anaeróbica; capacidad aeróbica; artes marciales; métricas de rendimiento. Resumo. Este estudo apresenta o Teste BJJFitness, uma ferramenta inovadora projetada para avaliar o desempenho físico e técnico dos praticantes de JiuJitsu Brasileiro (BJJ), distinguindo entre competidores e não competidores. O teste demonstrou alta consistência interna (alpha de Cronbach = 0.992) e forte confiabilidade teste-reteste (ICC = 0.894). Variáveis-chave como a frequência cardíaca em repouso, a frequência cardíaca durante o teste, o número de quedas e a taxa de percepção de esforço (RPE) foram críticas para diferenciar os dois grupos. Competidores apresentaram uma aptidão cardiovascular superior, proficiência técnica e menor percepção de esforço em comparação com os não competidores. O Teste BJJFitness simula as condições reais de combate, oferecendo um método de avaliação prático e abrangente que reflete as demandas únicas do BJJ. Esses achados ressaltam a importância do condicionamento específico e das habilidades técnicas para o sucesso competitivo no BJJ. O estudo também destaca o potencial do Teste BJJFitness como uma ferramenta valiosa para treinadores e atletas identificarem pontos fortes e áreas para melhoria, orientando intervenções de treina-mento direcionadas. Palavras-chave: avaliação fisiológica; capacidade anaeróbica; capacidade aeróbica; artes marciais; métricas de desempenho.
... Residual lung and gastrointestinal volume were estimated using previously developed prediction equations (37) and used to correct body density values. Body density was then converted to a body fat percentage using the Siri equation (34). ...
... The density calculation proposed by (Jackson & Pollock, 1978) and (Jackson et al., 1980) was applied (7 folds for men and 3 folds for women). After calculating body density, the Siri formula was used to obtain the fat percentage (Jackson et al., 1980;Jackson & Pollock, 1978;Siri, 1956). In addition, the present study measured the waist-to-hip ratio (WHR) by wrapping a flexible measuring tape around the narrowest part of the athlete's waist and recording the measurement, then measuring around the widest part of their hips. ...
This study introduces the BJJFitness Test, a novel tool designed to evaluate the physical and technical performance of Brazilian Jiu-Jitsu (BJJ) practitioners, distinguishing between competitors and non-competitors. The test demonstrated high internal consistency (Cronbach’s alpha = 0.992) and strong test-retest reliability (ICC = 0.894). Key variables such as resting heart rate, heart rate during the test, number of takedowns, and rate of perceived exertion (RPE) were critical in differentiating the two groups. Competitors exhibited superior cardiovascular fitness, technical proficiency, and lower perceived exertion compared to non-competitors. The BJJFitness Test mimics real-match conditions, providing a practical and comprehensive assessment method that reflects the unique demands of BJJ. These findings underscore the importance of specific conditioning and technical skills for competitive success in BJJ. The study also highlights the potential of the BJJFitness Test as a valuable tool for coaches and athletes to identify strengths and areas for improvement, guiding targeted training interventions. Keywords: physiological assessment; anaerobic capacity; aerobic capacity; martial arts; performance metrics.
... The remaining 22 participants were female athletes (♀n = 22) comprised of varsity volleyball, soccer, ice hockey, and track and field athletes. Participant race and ethnicity were not taken into consideration when recruiting but were accounted for when selecting the preprogramed software equation (Schutte et al., 1984;Siri, 1993). The sample size was calculated using G*Power computer software (G*Power, F. Faul, University Kiel, Germany;Faul, Erdfelder, Lang, & Buchner, 2007). ...
Pre-testing guidelines for assessing body composition using air plethysmography places significant difficulty when assessing hundreds of university athletes. Furthermore, there is limited evidence around the typical error for indices of body composition in Canadian female and male university athletes. This was a test re-test study examining the intra and inter-session reliability of the BOD POD® for assessing body composition. A total of forty-four university athletes volunteered as participants (♂︎n = 22 | ♀︎n = 22). Athlete were assigned two measurements on day one, a morning (AM1) and an afternoon (PM). On day two, participants returned for their second morning measurement (AM2). Each morning measurement required participants to be fasted and not have performed exercise for a minimum of 2h, while the afternoon measurement disregarded all pre-testing guidelines. The typical error (TE) from the intra -session reliability (AM1 ‘vs’ PM) in males and females for body weight (TE ≤ 0.50 kg, p ≤ 0.006), body fat (TE ≤ 0.87 %, p ≥ 0.244), and fat free mass (TE ≤ 0.67 kg, p ≤ 0.067) was minimal. The TE from the inter-session reliability (AM1 ‘vs’ AM2) in males and females for body weight (TE ≤ 0.45 kg, p ≥ 0.949), body fat (TE ≤ 1.10 %, p ≥ 0.195), and fat free mass (TE ≤ 0.83 kg, p ≥ 0.462) was marginal. This study demonstrated excellent reliability in assessing body composition when negating pre-testing guidelines and offers practitioners multiple possibilities for establishing the smallest worthwhile change in body composition.
... Foram realizadas as seguintes avaliações: i) Anamnese e avaliação antropométrica -medidas de massa corporal (kg), estatura (cm), índice de massa corporal (IMC), circunferência da cintura (cm), densidade corporal [10] e em seguida foi realizado o cálculo de percentual de gordura [11]. Além disso, foi determinado pela bioimpedância InBody ® 370s o cálculo de predição de massa magra e gorda de acordo com o protocolo recomendado [12]. ...
Introdução: A obesidade é um problema de saúde pública e vem aumentando de forma exponencial. Objetivo: Destacar a importância do trabalho multidisciplinar e discutir a utilização de uma técnica de execução que respeite o ordenamento das ações articulares das cinturas – escapular e pélvica envolvidas nos movimentos nos exercícios resistidos. Métodos: Um homem com 41 anos, obeso, com índice de massa corporal (IMC) de 42,58 kg/m2 e circunferência de cintura (CC) compatíveis para o alto risco de desenvolvimento de doenças cardiometabólicas foi submetido a um programa de intervenção multidisciplinar. Resultados: O indivíduo que participou do programa multidisciplinar supervisionado obteve melhorias consideráveis nos parâmetros de composição corporal, circunferências e razão cintura e estatura (RCE) e do perfil bioquímico pré e pós intervenção. Conclusão: O trabalho multidisciplinar é fundamental para melhoria da composição corporal, da CC e RCE e do perfil bioquímico. Além disso, critérios para padronização de uma técnica de execução que respeite a anatomia e a funcionalidade articular das cinturas escapulares e pélvica, assim como, a origem, a inserção e as ações musculares para obter um efetivo direcionamento da força deveriam ser objeto de discussão em pesquisas futuras. Palavras-chave: Síndrome metabólica; obesidade; exercício físico; estilo de vida.
... The following equations were used to predict the body fat percentage ( (2008) (Equation seven). The Siri Equation was used to convert body density into fat percentage (SIRI, 1961). The equations are available in Table 2. Legend: Equation three, gender (Ŧ), 0 to men and 1 to women; Equations four to seven, gender (Ŧ), 0 to women and 1 to men; age in years; Equation two and seven, heigh and hip circumference in meters. ...
401-Retos, número 59, 2024 (octubre) What is the best predictor of body fat percentage for older brazilian women? ¿Cuál es el mejor predictor del porcentaje de grasa corporal en las mujeres brasileñas ancianas? Abstract. This study aimed to investigate the validity of several equations and predictive indices for estimating body fat percentage (%BF) in 152 older women, with an average age of 67.4 years and an average body mass index (BMI) of 28.65 kg/m². To this end, anthropometric measurements including height, body weight, circumferences (waist and hip), and a dual energy X-ray absorptiometry (DXA) scan were performed. All measurements were performed by trained researchers following specific protocols. The results were compared to the dual energy X-ray absorptiometry (DXA) technique, which is considered the reference method. The analyzed equations showed moderate to good correlation coefficients with DXA, with particular emphasis on Visser's equation 6, which showed the best correlation (r = 0.752, p < 0.001). However, the agreement between the equations and DXA, as assessed by the Lin concordance coefficient, was classified as poor (ρc < 0.90). This indicates that although the equations have a positive correlation with body composition , they tend to deviate from the identity line when compared to the reference method. Additionally, the equations showed high sensitivity for detecting obesity when the cutoff point of 30% body fat was adopted, indicating a good ability to identify the presence of the condition. However, the equations, with the exception of equation 4, showed low specificity, meaning they had limited ability to detect normal individuals, resulting in a low negative predictive value. The results suggest that BF% equations and indices are dependent on the populations in which they were developed. The specificity and sensitivity of these equations may vary, and it is important to carefully select the most appropriate equation for estimating BF% in older Brazilian women. Resumen. Este estudio tuvo como objetivo investigar la validez de varias ecuaciones e índices predictivos para estimar el porcentaje de grasa corporal (%GC) en 152 mujeres mayores, con una edad promedio de 67,4 años y un índice de masa corporal (IMC) promedio de 28,65 kg/m². Para ello, se realizaron mediciones antropométricas que incluyeron altura, peso corporal, circunferencias (cintura y cadera) y una absorciometría dual de rayos X (DXA). Todas las mediciones fueron realizadas por investigadores capacitados siguiendo protocolos específicos. Los resultados se compararon con la técnica de absorciometría dual de rayos X (DXA), que se considera el método de referencia. Las ecuaciones analizadas mostraron coeficientes de correlación de moderados a buenos con DXA, con especial énfasis en la ecuación 6 de Visser, que mostró la mejor correlación (r = 0,752, p < 0,001). Sin embargo, la concordancia entre las ecuaciones y la DXA, evaluada mediante el coeficiente de concordancia de Lin, se clasificó como pobre (ρc < 0,90). Esto indica que, aunque las ecuaciones tienen una correlación positiva con la composición corporal, tienden a desviarse de la línea de identidad cuando se comparan con el método de referencia. Además, las ecuaciones mostraron una alta sensibilidad para detectar la obesidad cuando se adoptó el punto de corte del 30% de grasa corporal, lo que indica una buena capacidad para identificar la presencia de la afección. Sin embargo, las ecuaciones, con la excepción de la ecuación 4, mostraron una especificidad baja, lo que significa que tenían una capacidad limitada para detectar individuos normales, lo que resultó en un valor predictivo negativo bajo. Los resultados sugieren que las ecua-ciones e índices de %BF dependen de las poblaciones en las que se desarrollaron. La especificidad y sensibilidad de estas ecuaciones pueden variar, y es importante seleccionar cuidadosamente la ecuación más adecuada para estimar el % de GC en mujeres brasileñas mayores.
... The body density equations were converted into fat percentage by using the Siri equation: %BF = ((4.95/D) -4.50) × 100 for the purpose of the analysis [46]. ...
Method
Twenty inactive males (BMI 27.67 ± 0.88 kg/m², age 49.15 ± 2.58 years) participated in an eight-week were randomly assigned to one of three intervention groups (combined (CT), resistance (RT), and aerobic (AT)) exercise modalities to assess within-subject and between group changes in glycolipid profile. Data were analyzed using repeated measures ANCOVA.
Result
Pre-post mean values of body fat percentage (%BF), area under the curve (AUC), low density lipoprotein (LDL), high density lipoprotein (HDL) and total cholesterol (TC) decreased in all three groups. The main effect of exercise modality on the AUC (F (2, 26) = 10.577, P = 0.001, η² = 0.569) was significant. Post-hoc analyses revealed that the RT group (-30.653 ± 6.766, p = 0.001) with 11.53% and the CT group (M = -0.896, SE = 3.347, P = 0.015) with 3.79% exhibited significantly greater reductions in AUC compared to the AT group. LDL levels showed significant different between groups (F (2, 26) = 6.33, p = 0.009, η² = 0.442), specially significantly 3.7% lowered in AT (MD = 4.783, SE = 1.563, P = 0.002) and 3.79% lower in CT (MD = 4.57, SE = 1.284, P = 0.008) groups compared to the RT group. AT significantly reduced TC by 17.716 ± 5.705 mg/dL (p = 0.02) compared to RT, representing a 7.97% decrease.
Conclusion
Exercise type significantly influences lipid profiles and glycemic control. Notably, both aerobic and combined training demonstrated a superior ability to modulate the lipid profile, and resistance training and combined training were more effective in reducing the AUC.
Trial registration
May, 31st 2024. Registration no: PACTR202405463745521 “Retrospectively registered”.
... Sum of six skinfolds (triceps, subscapular, supraspinal, abdominal, mid-thigh and calf maximum) and eight skinfolds (triceps, subscapular, biceps, iliac crest, supraspinal, abdominal, mid-thigh and calf maximum) were calculated, and equations by Durnin and Womersley (1974), Jackson and Pollock (1978), and Rossato et al. (2018) were applied to estimate %FM. The Siri equation (Siri, 1993) was applied to determine FM in the aforementioned equations in basis of body density. ...
... Cont. For formulas that express body density, we computed % BF from the Siri equation[52]. b In this table, S7 = CH + SC + AX + TR + AB +SU + TH, and S3 = CH + AB + TH. ...
Body composition assessment helps conducting a healthy life or tracking the effectiveness of a weight management therapy. Ultrasound (US)-based body composition research has gained momentum because of the emergence of portable and inexpensive instruments bundled with user-friendly software. Previously, US-based assessment of body fat percentage (% BF) was found precise, but inaccurate in certain populations. Therefore, this study sought to compute % BF from subcutaneous fat thicknesses (SFs) given by US converting an anthropometric formula that involves skinfold thicknesses (SKFs) measured at the same sites. The symmetry of the body with respect to the central sagittal plane is an underlying assumption in both anthropometry and US-based body composition assessment, so measurements were taken on the right side of the body. Relying on experimental data on skinfold compressibility, we adapted 33 SKF formulas for US use and tested their validity against air displacement plethysmography on a study group of 97 women (BMI = 25.4 ± 6.4 kg/m2, mean ± SD) and 107 men (BMI = 26.7 ± 5.7 kg/m2). For both sexes, the best proprietary formula had Lin’s concordance correlation coefficient (CCC) between 0.7 and 0.73, standard error of estimate (SEE) < 3% BF and total error (TE) > 6% BF—mainly because of the underestimation of % BF in overweight and obese subjects. For women (men) the best adapted formula had CCC = 0.85 (0.80), SEE = 3.2% (2.4%) BF, and TE = 4.6% (5.4%) BF. Remarkably, certain adapted formulas were more accurate for overweight and obese people than the proprietary equations. In conclusion, anthropometric equations provide useful starting points in the quest for novel formulas to estimate body fat content from ultrasound measurements.
... The following equations were used to predict the body fat percentage ( (2008) (Equation seven). The Siri Equation was used to convert body density into fat percentage (SIRI, 1961). The equations are available in Table 2. Legend: Equation three, gender (Ŧ), 0 to men and 1 to women; Equations four to seven, gender (Ŧ), 0 to women and 1 to men; age in years; Equation two and seven, heigh and hip circumference in meters. ...
This study aimed to investigate the validity of several equations and predictive indices for estimating body fat percentage (%BF) in 152 older women, with an average age of 67.4 years and an average body mass index (BMI) of 28.65 kg/m². To this end, anthropometric measurements including height, body weight, circumferences (waist and hip), and a dual energy X-ray absorptiometry (DXA) scan were performed. All measurements were performed by trained researchers following specific protocols. The results were compared to the dual energy X-ray absorptiometry (DXA) technique, which is considered the reference method. The analyzed equations showed moderate to good correlation coefficients with DXA, with particular emphasis on Visser’s equation 6, which showed the best correlation (r = 0.752, p < 0.001). However, the agreement between the equations and DXA, as assessed by the Lin concordance coefficient, was classified as poor (ρc < 0.90). This indicates that although the equations have a positive correlation with body composition, they tend to deviate from the identity line when compared to the reference method. Additionally, the equations showed high sensitivity for detecting obesity when the cut-off point of 30% body fat was adopted, indicating a good ability to identify the presence of the condition. However, the equations, with the exception of equation 4, showed low specificity, meaning they had limited ability to detect normal individuals, resulting in a low negative predictive value. The results suggest that BF% equations and indices are dependent on the populations in which they were developed. The specificity and sensitivity of these equations may vary, and it is important to carefully select the most appropriate equation for estimating BF% in older Brazilian women. Keywords: Anthropometry; body composition; older adults.
... In some athletic settings, dual-energy x-ray absorptiometry (DXA) may be used to assess body composition, which provides a 3-compartment model and quantifies important parameters used to evaluate bone health, along with fat mass and lean body mass. As such, DXA provides an advantage for more accurately determining FFM because it does not rely on assumptions (48) for lean and bone mass as do 2-compartment models while also providing bone-specific metrics of interest. Reductions in FFM and bone mineral content or bone density can be indications of low energy availability (41). ...
Jagim, AR, Harty, PS, Jones, MT, Fields, JB, Magee, M, Smith-Ryan, AE, Luedke, J, and Kerksick, CM. Fat-free mass index in sport: normative profiles and applications for collegiate athletes. J Strength Cond Res XX(X): 000–000, 2024—Recent concerns have been raised regarding the ethical considerations of conducting body composition assessments in sports. Specific apprehensions pertain to the inappropriate use of percent body fat and the limited application of the results to performance and recovery. Fat-free mass index (FFMI), a height-adjusted assessment of FFM, can serve as an alternative body composition metric to focus on in sports. Fat-free mass index provides valuable context regarding an optimal amount of FFM, accounting for skeletal frame and height while helping to qualify an athlete's FFM as low, moderate, or high. This review posits that shifting the focus of body composition measures to FFM can support more ideal targets across athletic seasons, careers, and the return to play after injury. In addition, a FFM focus may help change the perception of body composition assessment and how athletes perceive their current body because of the increased focus on the FFM compartment and the goal of maximizing tissue accrual, rather than focusing on fat loss. Fat-free mass index is calculated by dividing FFM (kg) by height (m ² ) and can serve to normalize FFM, relative to height, and enable comparisons across athletes, sport types, and sex. Previous research has identified differences in FFMI across sex and among sport categories. Still, there is a need for more published data to develop optimal ranges for FFMI across sex, sports, and positions. As more data become available, FFMI has the potential to provide normative guidelines for optimal FFM development, performance, and injury risk reduction. The purpose of the current review was to summarize FFMI values across collegiate sport categories and competitive status to provide normative profiles, according to sex and sport type.
... BMI was calculated by dividing body weight by height squared. Body density was assessed using the mean of six measurements derived from the hydrostatic weighing technique (Behnke and Wilmore 1974); the Siri equation was used to estimate percent body fat (Siri 1956). To determine the pulmonary residual volume, the helium dilution method of Meneely and Kaltreider was used (Meneely and Kaltreider 1949). ...
The aim of this study was to assess the association between net mechanical efficiency (NME) and body composition and glycemic profile, in middle-aged (38.3 ± 14.3 years) participants from the Quebec Family Study (QFS). Analyses were completed on a sample of 605 participants (271 males and 334 females) who performed a submaximal exercise test on an ergometer consisting of three consecutive 6-min workloads at increasing intensity during which respiratory gas exchange was assessed. The calculation of NME [power output/ (vO2-vO2seated before exercise)] was based on the values of the last 3 min of the first workload at a targeted power output of 30 W. Correlations between NME and dependent variables were computed separately in males and females. Associations between NME and body composition and glucose–insulin variables were assessed by comparing groups of subjects categorized in sex-specific tertiles of NME after adjustments for age. Significant negative correlations were observed between NME and body composition and glycemic profile in both sexes. Comparison across tertiles showed that individuals with high NME displayed more favorable adiposity and glycemic profiles. These differences remained significant after further adjustments for participation in vigorous physical activity, cardiorespiratory fitness, and mean exercise respiratory exchange ratio whereas most differences in glucose–insulin variables became non-significant after further adjustment for percent body fat. QFS familial data indicate that the heritability of NME reaches about 30%. In conclusion, the results of this study show that beyond aerobic fitness and physical activity-participation, mechanical efficiency is an additional activity-related variable that is independently associated with variations in body composition and glycemic profile.
This study aims to evaluate the dietary intake of elite Indian Taekwondo athletes to determine their nutritional adequacy and compare it with other combat sports. Five male athletes participated, with an average age of 24.5 ± 2.5 years, weight 64.5 ± 5.5 kg, height 170 ± 5.5 cm, BMI 22.5 ± 0.5 kg/m2, and body fat percentage 9.5 ± 4.0%. The analysis was based on a three-day dietary record. The findings revealed nutritional inadequacies in protein and fiber intake, despite generally adequate intake of most macro- and micronutrients. Further studies during different training and competition phases could provide more insight into the nutritional risks associated with weight-category sports and the strategies used for competitive advantage.
The study aim was to analyse the effects of manipulating the space and number of players in
small-sided games on the external load demands of futsal athletes of different age categories. Fifty-six male
futsal players from U15, U17, U19, and adult age categories participated. The study lasted 7 weeks. The first
week was for familiarization and evaluations to characterize the sample. In the six subsequent weeks there were
six futsal tasks T1 (GK + 2 × 2 + GK, 20 × 20 m), T2 (GK + 2 × 2 + GK, 40 × 20 m), T3 (GK + 3 × 3 + GK,
20 × 20 m), T4 (GK + 3 × 3 + GK, 40 × 20 m), T5 (GK + 4 × 4 + GK, 20 × 20 m), and T6 (GK + 4 × 4 + GK,
40 × 20 m). The external load variables were measured with an inertial measurement unit (IMU), and kinematic
(total and relative distance) and mechanical (total distance at high intensity accelerations and decelerations) data
were extracted. T2 (133 m2) showed higher values for total distance covered (1248.0 ± 97.6 m) and distances
covered at speeds between 12.1 and 18 km/h (407.8 ± 44.7 m) and greater than 18.1 km/h (115.2 ± 28.9 m)
compared to T5 (40 m2) and T6 (80 m2). In addition, we observed greater variability in high-intensity accelerations
and high-intensity decelerations, suggesting that regardless of field size and number of players, relative area
might not play as crucial a role in this dimension.
Spirulina, a blue-green microalga, is high in protein, vitamins, minerals and antioxidants, making it a popular supplement for improving general health. Due to its potentiality for fat metabolism, the study aims to explore the effect of eight weeks of Spirulina supplementation in reducing body fat in overweight young males. Following CONSORT 2010 checklist, eight-week placebo-controlled trial has been implemented involving twenty participants. The experimental group received 5 grams of Spirulina supplementation for eight weeks. The intake frequency increased from 3 days per week in the first week to daily by the sixth week, ensuring controlled adaptation. No significant differences were found in demographic and anthropometric characteristics between the controlled and experimental groups. Spirulina supplementation led to a slight reduction in body fat percentage in experimental group, though the changes were not statistically significant (p=0.75). The reduction of body fat in the supraspinal and subscapular regions was relatively higher in the experimental group volunteers. The findings of the study indicate that providing overweight young boys with Spirulina supplementation for eight weeks did not have a significant impact on reducing body fat or modifying other physical measurements. The absence of significant change in body composition can be attributed to the duration of intervention, dosage and individual variability in response. The synergy of Spirulina supplementation and physical activity could be pivotal in effective weight control. Further research is required to examine the possible benefits of using Spirulina supplementation with other lifestyle strategies to achieve an effective reduction of body fat.
Objective : This study aimed to verify the association of anthropometric and motor variables with the competitive indicators of female athletes in the ABADÁ-Capoeira (Associação Brasileira de Apoio e Desenvolvimento da Arte Capoeira) World Games. Methods : Forty-two capoeira athletes from 15 countries (capoeira experience = 15.1 [7.9] y, age = 32.1 [8.8] y, body mass = 63.2 [6.3] kg, and height = 161.8 [4.4] cm) were recruited for anthropometric and motor evaluation of sit and reach, push-up, trunk flexion, countermovement jump (CMJ), and quadrant jump (QDJ). Each athlete’s ranking and stage scores in the competition were obtained as indicators of competitive performance. Results : There were inverse correlations between abdominal circumference, body mass index, body fat percentage, and endomorphy with motor variables (rho = −.36 to −.46; P < .05). Positive correlations of motor performance with competitive performance indicators were evidenced, being between the average increment score with the CMJ (rho = .33; P < .05) and the QDJ (rho = .35; P < .05), and between the competition score with the CMJ (rho = .32; P < .05) and the QDJ (rho = .32; P < .05). Additionally, the motor performance of trunk flexion ( β = 0.11; odds ratio = 1.126; 95% CI, 1.025–1.238), QDJ ( β = 0.21; odds ratio = 1.239; 95% CI, 1.022–1.503), and CMJ ( β = 0.20; odds ratio = 1.230; 95% CI, 1.029–1.471) predicted competition stage advancement. Conclusions : Associations occurred between anthropometry and motor performance, and this was predictive of competitive indicators of female capoeira athletes in international competition. Such information may contribute to an optimized and effective training process aimed at the integral improvement of capoeira practitioners’ body composition and motor skills, especially to improve localized muscular endurance of the upper limbs and abdomen, as well as agility and power of the lower limbs.
Introduction
DNA hypomethylation in patients with systemic lupus erythematosus (SLE) has been recently documented in the literature. Low levels of DNA methylation have been observed globally and in genes associated with immune and inflammatory pathways in SLE’s CD4+T lymphocytes. Given that certain micronutrients can either donate methyl groups within one-carbon metabolism pathways or serve as cofactors for enzymes involved in the DNA methylation process, this randomised, double-blind, placebo-controlled trial aims to investigate whether a 3-month supplementation of folic acid and vitamin B 12 will modulate the DNA methylation profile in subcutaneous adipose tissue (primary outcome) of women with SLE and normal weight or excess body weight. As secondary objectives, we will assess gene expression, telomere length and phenotypic characteristics (ie, clinical parameters, body weight and composition, abdominal circumference, food intake and disordered eating attitude, physical activity, lipid profile, serum concentrations of leptin, adiponectin, and cytokines).
Methods and analysis
Patients will be classified according to their nutritional status by body mass index in normal weight or excess body weight. Subsequently, patients in each group will be randomly assigned to either a placebo or an intervention group (folic acid (400 mcg) and vitamin B 12 (2000 mcg) supplementation). Endpoint evaluations will be conducted using both intention-to-treat and per-protocol analyses. This study has the potential to design new personalised nutritional approaches as adjunctive therapy for patients with SLE.
Ethics and dissemination
This study has been reviewed and approved by the Ethical Committee from Clinical Hospital of the School of Medicine of the University of Sao Paulo, Brazil (CAAE.: 47317521.8.0000.0068).
Trial registration number
NCT05097365 (first version).
This study aims to evaluate the dietary intake of elite Indian Taekwondo athletes to determine their nutritional adequacy and compare it with other combat sports. Five male athletes participated, with an average age of 24.5 ± 2.5 years, weight 64.5 ± 5.5 kg, height 170 ± 5.5 cm, BMI 22.5 ± 0.5 kg/m², and body fat percentage 9.5 ± 4.0%. The analysis was based on a three-day dietary record. The findings revealed nutritional inadequacies in protein and fiber intake, despite generally adequate intake of most macro-and micronutrients. Further studies during different training and competition phases could provide more insight into the nutritional risks associated with weight-category sports and the strategies used for competitive advantage.
Objective
This cross-sectional study aimed to investigate the role of low energy availability (LEA) in the interplay between depression and disordered eating/eating disorders (DE/EDs) among female athletes. The International Olympic Committee consensus statement on Relative Energy Deficiency in Sport (REDs) identified depression as both an outcome of LEA and a secondary risk factor for REDs. However, the direct link between LEA and depression has yet to be fully established.
Methods
We assessed 57 female athletes participating in weight-sensitive sports at different levels of competition training at least four times a week. Assessment was conducted using laboratory analyses, clinical interviews and the Patient Health Questionnaire-9 questionnaire. Participants were recruited through various channels, including German sports clubs, Olympic training centres, social media platforms and the distribution of flyers at competitions. Indicators of LEA were defined if at least two of the following three physiological indicators were present: menstrual disturbances, suppressed resting metabolic rate and suppressed thyroid hormones. Logistic and linear regression analysis were used to examine the relationship between LEA, depression and DE/ED.
Results
The lifetime prevalence of depressive disorders was 29.6%. 19% of the participants were diagnosed with an ED, and an additional 22.6% exhibited DE.LEA was not significantly associated with either lifetime prevalence of depressive disorders or current depressive symptoms. However, a significant association was found between depression and DE/ED in terms of both lifetime prevalence and current depressive symptoms. DE/ED increased the probability of lifetime prevalence of depressive disorders by 34% (19%–49%) compared with normal eating behaviour.
Conclusion
We found no evidence that LEA is an independent factor for depression in female athletes. Its association with LEA and REDs appears to occur primarily in the presence of DE/ED.
There has been an increasing interest among CrossFit® coaches and practitioners in identifying indicators of sport performance. This study aimed to examine the correlation between anthropometric measures, cardiorespiratory capacity, power, local muscle endurance, and total athleticism score, with performance in the CrossFit® Open 2021. Fourteen male volunteers (aged 30.3 ± 5.8 years) participated in the study and underwent a series of tests on separate weeks. These tests included assessments of body fat percentage (subcutaneous adipose thickness measured at seven sites), maximal oxygen consumption (2 km test in rowing ergometer), muscle power (one repetition maximum in power clean), and muscle endurance (Tibana test, which included the conclusion of four distinct rounds of work). These results were used to calculate the total score of athleticism, which was then compared to the participants performance during the CrossFit® Open 2021. The athletes presented an average of body fat (8.6 ± 2.0%), maximal oxygen consumption (53.3 ± 2.4 mL. (kg.min)-1), 2km row time (07:00 ± 00:21 mm:ss), 1-Repetition maximum in power clean (125.2 ± 21.2 kg) and Tibana test performance (281.0 ± 35.9 repetitions). Interestingly, the top five athletes with the highest scores also achieved the highest z-scores in the CrossFit® Open 2021. Conversely, the four athletes with the lowest TSA score had the lowest z-scores in the CrossFit® Open. Moreover, almost perfect correlation (r = 0.91; p<0.01) was found between the total athleticism score and z-scores in the CrossFit® Open 2021. The total score may be a single measure and holistic indication of athleticism level in CrossFit®. Furthermore, coaches can potentially apply this useful tool for monitoring athletic performance and designing training sessions that address specific areas of CrossFit® performance.
ALMAGIÀ F. A. A.; ITURRIAGA, Z. M. F. & RODRÍGUEZ, B. F. Comparación de la composición corporal y de la masa muscular por segmentos corporales, en estudiantes de educación física y deportistas de distintas disciplinas. Int. J. Morphol., 30(1):7-14, 2012. RESUMEN: Las ecuaciones antropométricas para estimar la masa muscular, permiten obtener los valores de sólo la masa muscular total (MM total). En un reciente trabajo (Rodríguez et al., 2010), propone una ecuación para la estimación de la masa muscular de los miembros superiores e inferiores. Se evalúan 68 sujetos, estudiantes de educación física, rugbistas, futbolistas y gimnastas. El grupo de rugbistas presenta mayor cantidad de masa muscular en los miembros superiores (MMES) que el resto de los grupos. La MM total y la Masa muscular de los miembros inferiores (MMEI) son significativamente más altas en los rugbistas y futbolistas en compara-ción a los otros sujetos. La distribución de la masa muscular por regiones corporales es distinta entre las disciplinas deportivas, ya que los requerimientos musculares difieren de uno a otro, volviéndose cada deportista, especialista en su área de desarrollo motriz. La MMEI representa más de mitad de la MM total, por lo tanto a mayor MMEI, mayor MM total.
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