Orientador: Antonio de Azevedo Barros Filho / Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Ciencias Medicas / Made available in DSpace on 2018-08-07T12:15:19Z (GMT). No. of bitstreams: 1 Cocetti_Monize_D.pdf: 4184206 bytes, checksum: 2c3d8f738ef8e44e22af1cab17355eca (MD5) Previous issue date: 2006 / Resumo: Este é um estudo transversal que teve como objetivo principal comparar peso, a altura, o Índice de massa corporal e a composição corporal de 6998 escolares, de 7 a 17 anos, matriculados em escolas públicas e particulares da rede de ensino do Município de Campinas, SP., além de avaliar a prevalência de sobrepeso e obesidade nos adolescentes. Foram realizadas medidas de peso, altura, circunferência do braço (CB), circunferência da cintura (CC), dobras cutâneas triciptal (DCT) e subescapular (DCSE) e aplicação do método de bioimpedância elétrica (BIA). As medidas derivadas foram índice de massa corporal (IMC), área muscular do braço (AMB), área de gordura do braço (AGB), % de gordura corporal (%GC), massa gorda (MG) e massa magra (MM). As variáveis foram agrupadas por idade, sexo e tipo de escola, e distribuídas em percentil. O IMC foi utilizado para avaliar sobrepeso (P=85) e obesidade (P=95), usando como referencial as curvas do Centers for Disease Control and Prevention (CDC, 2000). Foi verificado se existia diferença estatisticamente significante entre as variáveis em função da idade, sexo e tipo de escola. As medidas de altura, peso e IMC foram estatisticamente significantes, respectivamente, até os 16 anos, 15 anos e 14 anos, em função do tipo de escola, sendo maiores nas escolas particulares. Enquanto as medidas de %GC, MG, DCSE e AGB foram estatisticamente significantes, em todas as idades, em função do sexo e tipo de escola. A prevalência de sobrepeso foi de 11,1% e de obesidade foi de 5,6%. O sobrepeso e a obesidade foram maiores nas escolas particulares do que nas publicas, respectivamente, 14,5% vs 9,2% (p<0,01) e 7,9% vs 4,4% (p<0,01), e nos meninos do que nas meninas, respectivamente, 12,3% vs 10,2 (p<0,01) e 8,3% vs 3,7% (p<0,01). Os escolares deste estudo atingem peso, altura e IMC semelhantes ao final da adolescência, porém com diferenças significativas na composição corporal, com maior prevalência de obesidade e percentual de gordura corporal entre as crianças e adolescentes das escolas particulares do que nas públicas. / Abstract: The main purpose of this cross sectional study was to evaluate the body composition and growth of 6,998 children and adolescents aged between 07 and 17 years, enrolled at public and private schools in the city of Campinas, 8ao Paulo. In addition to assessment of overweight and obesity prevalence in the adolescents. Measurements were also taken of weight, height, arm circumference (AC), waist circumference (WC), triceps skinfold thickness (TSFT), subscapular skinfold thickness (SSFT) and bioelectrical impedance (BI). The derived measures were body mass index (BMI), arm muscle area (AMA), arm fat area (AFA), body fat percent (%BF), lean body mass (LM) and fat mass (FM). The variables were grouped according to age, sex and type of school and then transformed into percentiles. The BMI was used to evaluate overweight (p=85) and obesity (p=95) using the CDC (2000) as reference. The existence of a statistically significant difference in growth assessment measures in relation to age, sex and type of school was verified. Among the adolescents, weight, height and BMI were statistically significant in relation to sex and type of school. Measures of %BF; FM, 88FT and AMA were statistically significant for all ages in relation to sex and type of school. Overweight prevalence was 11.1 % and obesity was 5.6%. Both overweight and obesity were higher in private schools than in public schools respectively, overweight 14,5 vs 9,2 (p<0.0l) and obesity 7,9 vs 4,4 (p<0.01) and boys than girls, respectively, 14,5 vs 9.2 (p<0.0l) and 7,9 vs 4,4 (p<0.01). The schoolchildren in this study reach weight, height and BMI of similar values at the end of puberty, but with different results related to the body composition, with higher prevalence of obesity and percent of fat among schoolchildren of private schools than public schools. / Doutorado / Saude da Criança e do Adolescente / Doutor em Saude da Criança e do Adolescente

Orientador: Ilza Maria Urbano Monteiro / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Ciências Médicas / Made available in DSpace on 2018-08-18T16:34:25Z (GMT). No. of bitstreams: 1 Souza_NataliaDal'Avade_M.pdf: 3987780 bytes, checksum: 87cbe713744ff30edfda9fbb824934f4 (MD5) Previous issue date: 2011 / Resumo: OBJETIVO: Avaliar a variação da composição corporal e comparar a densidade mineral óssea de usuárias de sistema intrauterino liberador de levonorgestrel (SIU-LNG) com usuárias de dispositivo intrauterino TCu 380A (DIU TCu 380A). SUJEITOS E MÉTODOS: Estudo de coorte prospectivo com acompanhamento de um ano, composto por dois grupos: 38 usuárias de SIU-LNG, como grupo estudo e 38 usuárias de DIU TCu 380A, como grupo-controle, pareadas por índice de massa corpórea (kg/m2 )(± 2) e idade (± 2 anos), selecionadas no Ambulatório de Planejamento Familiar do Centro de Atenção Integral à Saúde da Mulher (CAISM) da Universidade Estadual de Campinas (Unicamp). Para avaliação da mudança de composição corporal utilizaram-se variações percentuais de massa gorda e de massa magra e do peso (kg). O estudo da massa óssea incluiu a mudança total e percentual da densitometria mineral óssea (DMO) de coluna (L1-L4), fêmur total e colo femoral pela técnica de absorciometria de duplo feixe de raio-X (DEXA). A primeira avaliação foi realizada antes de se iniciar o uso do método contraceptivo e a segunda após um ano de uso do método. A evolução e a diferença entre os grupos quanto à densidade mineral óssea foram avaliadas através do teste t-Student pareado e Wilcoxon pareado. RESULTADOS: A idade média (±EP) foi 34,4 (±1.2) e 34 (±1.3) anos, IMC foi 25.1 (± 0,7) e 25,9 (± 0,7), e o número de gestações foi 1,9 (±0,2) e 1,7(±0,2) em usuárias de SIU-LNG e DIU TCu380A, respectivamente. Houve uma perda de massa óssea significante de 0,5% em coluna lombar das usuárias de SIU-LNG e um aumento de massa óssea de 1,4% e 1,5% em colo femoral e coluna lombar em usuárias de DIU TCu380A. Os dois grupos tiveram aumento no peso corporal, mas não houve diferença significativa entre eles aos 12 meses. O percentual de gordura aumentou nas usuárias do SIU-LNG, enquanto o grupo DIU TCu380A teve aumento de massa magra aos 12 meses. CONCLUSÕES: O grupo SIU-LNG apresentou pequena perda de massa óssea no primeiro ano de uso do método, provavelmente sem significância clínica. O grupo do DIU TCu 380A, que ganhou massa magra, apresentou também ganho na massa óssea em colo femoral e coluna lombar / Abstract: OBJECTIVE: This study evaluated body composition and bone mineral density in users of levonorgestrel-releasing intrauterine system (LNG-IUS) and compared to TCu380A intrauterine device (IUD) users. SUBJECTS AND METHODS: A prospective group study conducted for 12 months with 38 LNG-IUS users and 38 TCu 380A IUD users, were paired by age (± 2 years) and the body mass index (kg/m²) (±2), recruited at Woman Hospital of University of Campinas (Unicamp). Two evaluations were realized about the body composition and bone mineral density of the Lumbar Spine (L1-L4), femoral neck and total femur through the technique of dual x-ray absorciometry (DEXA). The first evaluation is going to be at the beginning of the use of the contraceptive method and the second will be after the method has been used for one year. The data was evaluated trough t- Student test for paired samples, Wilcoxon, and Chi-square. RESULTS: The mean (±SEM) age was 34.4 (±1.2) years old and 34 (±1.3) years old, BMI was 25.1 (± 0.7) and 25.9 (± 0.7) and with 1.9 (±0.2) and 1.7 (±0.2) pregnancies in LNG-IUS and TCu380A IUD users, respectively. There was a significant decrease in BMD of 0.5% in LNG-IUS at LS and an increase of 1.4% and 1.5% in TCu380A IUD users at FN and LS, respectively when compared values at baseline and at one year of use. The two groups had an increase in body weight; however, without significance between groups at 12 months. LNG-IUS users showed a fat percentage increased; notwithstanding, the TCu380A IUD users had an increase of lean mass, both at 12 months. CONCLUSIONS: It was observed a small loss of BMD up to the 1st year of LNG-IUS use; probably without clinical significance. The TCu380A IUD users presented increase of lean mass and increase of BMD at FN and LS / Mestrado / Fisiopatologia Ginecológica / Mestre em Ciências da Saúde

Title: The relationship of body composition and aerobic fitness in the elderly Objectives: The aim of this study was to determine the aerobic fitness of students at University of Third Age at the UK FTVS and to investigate whether there exists an association between body composition and aerobic fitness. Methods: The research involved 54 seniors (age 64 ± 2.71 years, body height 163.23 ± 6.05 cm) who studied at University of the 3rd Age at the UK FTVS at the time of research. The original sample of probands was 91, but people aged over 70 years and people taking heart-rate medications had to be excluded. Measurments of body composition was performed using BIA 2000M multifrequency bioimpedance analysis. The investigated parameters were total body water (TBW), intracellular water (ICW), extracellular water (ECW) in litres, fat free mass (FFM) in kg, percentage of body fat (% BF) and extracellular and body cell mass ratio (ECM/BCM). Measurement of aerobic fitness was performed by a 2 km test pass, evaluated by Stejskal at the athletic stadium UK FTVS. Time and heart rate were scanned by sporttester (Polar S 610i). The data was processed using the IBM SPSS statistics 22. Results: The results showed that our group belongs to "avarage seniors" in terms of aerobic fitness. A significant relationship...

A Thesis submitted to the Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, in ful lment of the requirements for the degree of Doctor of Philosophy in Medicine Johannesburg, South Africa 2017. / Background: The persistent burden of undernutrition, with increasing prevalence of obesity and metabolic disease risk among children and adolescents, has become a global public health problem. Research has shown that risk factors established in childhood and adolescence may contribute to the development of non-communicable diseases (NCDs) in adulthood. This is of particular concern in South Africa, given its rapid socio-economic, political and epidemiological transitions. Research into the trends of nutrition transition in rural children and adolescents, whose particular health needs have been under-served and poorly delineated in the past, provides a unique opportunity to study the e ects of rapid health transitions on development. Aim: To determine the association of nutrition, body composition and metabolic disease risk in rural South African children and adolescents. Study design: Three cross-sectional studies were undertaken to address the overall aim of this research. The speci c objectives of each study were: (1) to determine the association of nutrition on body composition and metabolic disease risk in children and adolescents; (2) to examine the associations between body mass index (BMI), disordered eating attitude and body dissatisfaction in female adolescents, and descriptive attributes assigned to silhouettes of di ering body habitus in male and female adolescents; and (3) to investigate associations between diet and cardiovascular disease (CVD) risk factors in adolescents. Method: One cross-sectional study, 3 analyses were nested within the Agincourt Health and Socio-demographic Surveillance System (HDSS) site, in the Bushbuckridge subdistrict, Mpumalanga Province, South Africa. In 2009, a random sample of 600 children and adolescents, from age groups 7 to 8 years, 11 to 12 years and 14 to 15 years, were selected from 3489 children who had participated in a 2007 growth survey. These children and adolescents had to have lived in Agincourt at least 80% of the time since birth or since 1992, when enrolment into the Agincourt Health and Socio-Demographic Surveillance System (HDSS) began. Height and weight were measured to determine BMI. Age and sex-speci c cut-o s for underweight and overweight/obesity were determined using those of the International Obesity Task Force. Body image satisfaction using Feel-Ideal Discrepancy (FID) scores, Eating Attitudes Test-26 (EAT-26), perceptual female silhouettes and pubertal assessment were collected through self-administered questionnaires. Blood pressure (systolic (SBP) and diastolic (DBP)) was measured, fasting blood samv ples were collected for the determination of glucose and lipids. Waist to hip ratio cut-o s of (WHR) >0.85 for females, >0.90 for males, waist to height ratio (WHtR) of >0.5 for both sexes, and waist circumference (WC) of >80 cm for females and >94 cm for males were used to determine the risk of adiposity. For abnormal lipids: high density lipoprotein cholesterol (HDL-C) cut-o s of >1.03 mmol/l, low density lipoprotein-cholesterol (LDL-C) of >2.59 mmol/l, triglycerides (TGs) of >1.7 mmol/l and total cholesterol (TC) of >5.17 mmol/l were used. Pre-hypertension prevalence was computed using the average of 2 readings of SBP or DBP, being >90th but <95th percentile for age, sex and height. Dietary intake was assessed using semi-quantitative food frequency questionnaire. T-test and ANOVAs for normally distributed data and Wilcoxon-Mann- Whitney test was used to determine signi cant di erences by sex and by pubertal stages for EAT-26 and EAT-26 sub-scores. Chi square tests were done to determine signi cant associations between the categorical variables. Bivariate linear regression was employed to test associations and signi cant tests were set at the p<0.05 level. Results: Study component (1): Stunting levels were higher in the boys than in the girls in mid to late childhood and combined overweight and obesity prevalence was higher in girls than in boys. The girls' BMI was signi cantly greater at ages 11 and 12 years than that of the boys [girls: 18 3.4, 95% con dence interval (CI): 17.33- 18.69; boys: 17 2, 95% CI: 16.46-17.25; p-value 0.004] and at ages 14-15 years (girls: 22 4.1, 95% CI: 20.82-22.47; boys: 19 2.4, 95% CI: 18.39-19.38; p-value < 0.001). Prehypertension (de ned as < 90th centile for age, sex and height) was higher in girls (15%) than boys (10%). Further, impaired fasting glucose was detected in 5.3% of girls and 5% of boys. High-density lipoprotein cholesterol (>1.03 mmol/l) concentrations were observed in 12% of the girls and 0.7% of the boys, which is indicative of cardiometabolic risk. Study component (2): The prevalence of overweight and obesity was higher in girls than boys in early and mid to post pubertal stages. The majority (83.5%) of the girls reported body image dissatisfaction (a desire to be thinner or fatter). The girls who wanted to be fatter had a signi cantly higher BMI than the girls who wanted to be thinner (p=0.001). There were no di erences in EAT-26 score between pubertal groups, or between boys and girls within the two pubertal groups. The majority of the boys and the girls in both pubertal groups perceived the underweight silhouettes to be \unhappy" and \weak" and the majority of girls in both pubertal groups perceived the normal silhouettes to be the \best". Study component (3): Added sugar and sweets contributed 10% and maize meal and vi bread contributed 7.2% to the total number of food items consumed respectively. Girls had higher intakes of total fat, saturated fat and cholesterol after adjusting for dietary energy intake and age (all p<0.001). The prevalence of combined overweight and obesity was 13.8% in girls and 3.1% in boys (p<0.001). In addition, indicators of adiposity were higher in females, abnormal waist circumference (WC) (6.7%), waist to hip ratio (WHR) (22.0%) and waist to height ratio (WHtR) (18.0%), compared to males, (0%), (3.1%) and (6.2%) respectively (all p<0.001). Girls had higher low-density lipoprotein (LDL) (12(9.3%) vs. 3(2.3%), p=0.01), total cholesterol (17(12.7%) vs. 5(3.5%), p<0.001) and were more pre-hypertensive (28(15.3%) vs.15(8.4%), p=0.04) than the boys. Furthermore, the bivariate associations between dietary intakes (total energy, total carbohydrate (CHO), total dietary fat and saturated fat) and anthropometric indices (BMI and WC) showed that body mass index (BMI) was associated with total energy (p=0.05) and BMI and WC were associated with total fat (p=0.01, p=0.03) and saturated fat (p<0.001, p=0.02) in females respectively. Conclusions: In conclusion, this thesis highlights that girls in rural South Africa had a higher prevalence of combined overweight and obesity than did boys, stunting was more prevalent amongst boys than girls in mid to late childhood and metabolic risk factors that were associated with adiposity, and linked to diet, were higher in girls than in boys. This study has provided useful information for targeting critical health promotion intervention programmes to optimise child nutrition as part of a noncommunicable disease preventative strategy, especially, in remote areas in rapidly transitioning South Africa. / LG2018

Title: Intervention program XY and its effect in weight reduction Objectives: The main aim of the master thesis was to find out the influence of a commercial intervention program XY containing nutritional recommendations on selected indicators of physical fitness and body composition Methods: This thesis was implemented as a quasi-experimental study in which the results were evaluated by both quantitative and qualitative methods. Results: We can evaluate the results in two groups, namely according to the results of body composition and the indicator of physical fitness. In addition to the long jump test, the mean values improved statistically significantly (p <0.05) in all monitored variables. In general, the XY intervention program aimed at weight reduction can be evaluated positively. Key words: obesity, body composition, unifittest (6-60)

Purpose: The purpose of this study was to determine how differences in hydration states and ion content of hydrating fluids affected bioelectrical impedance (BI) and hydrostatic weighing (HW) measurements. Methods: Fifteen athletic subjects aged 19-56 yr were recruited. Relative body fat (%), fat- weight (FW), and fat-free weight (FW) were assessed using BI and HW under normal conditions (N), hypohydration (HPO), rehydration (RHY), and superhydration (SHY) states. During the RHY and SHY trial periods, subjects were hydrated with either distilled water or an electrolyte solution (ELS). HPO and SHY levels were set at 3% of each person's normally hydrated body weight. Results: Comparison between the distilled water and the ELS trials indicated that hydration solution had no effect on BI or HW. Thus, the results presented are the trial means of both hydration solutions combined. Both BI and HW were shown to be highly test-retest reliable (r-values: 0.96 and 0.99, respectively). The effects of exercise induced HPO followed by RHY on body composition values indicated that HW was very stable across measurement periods while BI was not. From N to the HPO state, BI %BF declined from 14.4 ± 5.3% to 12.3 ± 5.3%, respectively. After RHY, BIA %BF increased to 15.5 ± 5.8%. Similar findings occurred when subjects were superhydrated (N-BI = 13.2 ± 5.3%; SHY-BI = 15.4 ± 5.6%). With a comparison of the intercepts and slopes of HW and BIA for the N and SHY states, it was clear hydration status significantly affected the intercepts (HW: 0.37 vs. BI: 1.85) and not the slopes (HW: 1.00 vs BI: 0.99). As a result, a majority of all fluid changes were interpreted as FW by BI. During HPO, 82% of the weight loss was considered FW while during RHY or SHY, 128% and 85% of the water weight regain/gain was considered FW. Conclusion: These results indicate that BI is not a valid technique in athletes, especially when wanting to determine body composition effects of training/detraining. This study indicates that even small fluid changes such as those that occur with endurance training may be interpreted incorrectly as changes in an athlete's body fat content.

Aerobic exercise training is used for rehabilitation in patients with chronic obstructive pulmonary disease (COPD), although it has little effect on muscle weakness and atrophy. Resistance training may be a useful addition to aerobic programs for these patients. The purpose of the present study was to investigate the effects of resistance training in addition to aerobic training on functional outcomes in patients with COPD. Seventeen COPD patients enrolled in an aerobic-based program that met twice a week were assigned to a 12-week control/aerobic [CON: n=8; 63 (8) years; mean (SD)] or a resistance/aerobic group [RES: n=9; 61 (7) years]. RES trained an additional twice a week on 12 resistance machines, performing three sets of 8-12 repetitions at 32-64% of their one-repetition maximum (1-RM) lifts. RES (P<0.05) increased upper (36%) and lower (36%) body strength, as well as lean body mass (5%), while CON showed little to no change. The 12-min walk distance increased (P<0.05) in only the RES [676 (219) to 875 (172) m]. Measurements of three of the eight tasks of activities of daily living improved in RES (P<0.05) compared to CON. This study demonstrated that progressive resistance training was well tolerated and improved functional outcomes in COPD patients that were currently involved in an aerobic training program.

The measurement of total body volume (V) (excluding lung volume) together with total body mass (m) is required in order to determine body density (d = m/V). From this, and using certain simplifying assumptions, it is possible to derive body composition in terms of fat mass (FM) and fat free mass (FFM) for the two-compartment model. The standard method for determining body volume (and hence body composition) is the densitometric (underwater weighing) technique based on Archimedes' principle. Three variables, notably residual lung volume (RV), total body mass (m) and submerged body mass are measured. RV is normally determined using a gas dilution technique while total body mass is simply measured using an accurate weighing scale. The submerged body mass is measured while the subject is totally submerged in a tank of water. This method, although relatively accurate, requires substantial apparatus and is time consuming. An alternative method, based on a polytropic thermodynamic process, is described for body volume measurement and thereby for body composition assessment. Previous use of this method by Taylor, et al. (1985) and Gundlach and Visscher (1986) were successful, but complex in terms of operating system. The described system comprises of a Perspex, sealed chamber. A cycling piston communicates with the chamber and imposes a minute sinusoidal pressure variation which is then measured. With a subject situated inside the chamber an increased pressure variation, caused by the decreased chamber volume, is then measured and processed to yield the displaced, or body volume. Subject comfort, above all, is greatly enhanced, in comparison to the underwater weighing method. A substantial advantage of the method appears to be that RV need no longer be measured. Variables such as a rise of temperature and humidity caused by the subject, as well as pressure variations due to respiration, were expected and found. These were analyzed both theoretically and experimentally and where necessary the data were modified to account for these variables using a personal computer. Calibration and preliminary validation of the instrument has been carried out using underwater weighing, bioimpedance and skinfold analyses and the error of measurement assessed. It appears that the described plethysmographic method is capable of measuring body volume and thus compares favourably to the underwater weighing method. Even though other groups have succeeded in employing similar principles, a substantially simpler mechanism has been used here.

Currently, about 1 in 3 women of reproductive age are obese (Flegal, Kruszon-Moran, Carroll, Fryar, & Ogden, 2016). Obesity in pregnancy has been associated with adverse maternal and infant outcomes (“Clinical Management Guidelines for Obstetrician–Gynecologists. Number 49, December 2003,” 2003) and maternal overweight and obesity have been implicated as increasing the risk for early childhood obesity (Ramonienė et al., 2017). Obesity is defined by the World Health Organization as having a body mass index (BMI) greater than 30 kg/m2, however, there is mounting evidence that BMI is not an accurate measure of adiposity (Kennedy, Shea, & Sun, 2009), which is one of the leading clinical concerns surrounding obesity. Understanding the associations between maternal body composition and infant body composition could begin to answer questions regarding the underpinnings of intergenerational obesity and offer a modifiable factor such as body composition as a target of opportunity to improve maternal and infant outcomes. This secondary analysis of 372 mother-infant dyads examines the associations of maternal body composition, as measured by BMI, fat mass and lean mass, with infant body composition, as measured by fat mass, lean mass, and BMI z-scores. Fat and lean masses were derived from dual-energy x-ray absorptiometry (DXA). Correlations between maternal BMI and maternal fat and lean mass were explored at one month postpartum. Associations between maternal body composition exposures at one month postpartum and infant body composition outcomes at one, four, and seven months postpartum were explored in the entire cohort and then stratified in two separate analyses by maternal BMI and infant sex to determine the potential for effect modification. Maternal BMI was strongly correlated with maternal fat mass at one month postpartum (r=0.91), and less strongly correlated with maternal lean mass (r=0.71). Maternal lean mass was positively associated with infant lean mass at four months postpartum. In obese women, maternal BMI was negatively associated with infant lean mass at seven months postpartum. In overweight women, maternal fat mass and maternal lean mass were positively associated with infant lean mass. In obese women, maternal fat mass was negatively associated with infant lean mass at four months postpartum. Maternal fat mass and lean mass were positively associated with infant lean mass at four and seven months postpartum in females but not in male infants. An increase in maternal lean mass was also found to be associated with a significant increase in female infant BMI z-scores at seven months postpartum but were not associated with male infants’ BMI z-scores. This study found that obese women with increased adiposity, as measured by BMI and fat mass, tended to have infants with less lean mass at four and seven months postpartum, while overweight women with increased lean mass tended to have infants with greater lean mass at all postpartum through seven months postpartum. It was also found that female infants born to mom’s with larger fat mass or larger lean mass tended to have increased lean mass at four and seven months postpartum, while there seemed to be no associations with maternal and infant body composition in male infants. These results confirm that the first year of life is an important time in infant development and potential programming, but they also suggest that this programming may be associated with lean mass accrual in early infancy as opposed to fat mass or adiposity. The complexity of the relationships between maternal and infant body composition in the postpartum period may involve other factors such as sex differences, genetics and nutrition, and should be further explored in future studies.

Health care professionals require accurate measurements of body composition and the hydrostatic weighing method is widely used as a reliable technique. Hydrostatic weighing measures body density accounting for an individuals residual volume (RV). To determine differences of RV measured in air (RVA) and in water (RVW), college-age men and women (n=51) were randomly assigned to one of four groups: female RVA, female RVW, male RVA, or male RVW. To account for possible gender differences with protocol (RVA vs. RVW) male and female subjects were treated as separate groups. RVW subjects began the first two trials in water followed by two trials out of water. If RV measures differed by more than 200 ml between the first two trials either in water or in air, a third or fourth trial was completed until two RV measures were within 200 ml of each other. The two trials were then averaged to determine the RVW. The same procedure was used for RVA subjects. RV was determined by the closed circuit helium dilution method. A 2-factor repeated measures ANOVA revealed that there was no statistically significant interaction between genders and protocols, a statistically significant difference between genders, and a statistically significant difference between protocols (RVA vs. RVW). The RV mean decreased with immersion in water among college-age subjects. A decrease in RV will have a marked increase in estimation of percent body fat. Therefore, the results of this study indicate that measuring RV during immersion in water on college-age men and women, to accurately assess body composition, is a valid and recommended protocol.