Hydrostatic Weighing Research Articles

Body composition in athletes: A comparison of densitometric methods and tracking of individual differences

Measuring body composition in athletes can provide valuable information on training and nutritional status. The aim of this study was to compare percentage body fat (PF) obtained by hydrostatic weighing (HW) to PF via air-displacement plethysmography (ADP), and to evaluate tracking of individual differences between both methods over time in elite college athletes. Thirty-one male and 33 female athletes (18.0–36.4 years) were measured by ADP and HW. Twenty-one subjects (10 men, 11 women) were measured again 61±11 days later to evaluate consistency of individual differences between methods. Mean PF differed significantly in men (HW: 9.4±2.4%, ADP: 11.3±3.4%, P<0.05) but not in women (HW: 19.1±2.4%, ADP: 19.5±3.7%). A significant trend in mean bias was found in both genders between HW-ADP suggesting an underestimation of PF by ADP at lower mean PF and an overestimation of PF by ADP at higher mean PF. Up to 73% of variance in differences between methods at follow-up was explained by differences between methods at the first measurement occasion. Both densitometric methods cannot be used interchangeably when measuring and tracking the body composition of individual elite athletes using a 2-component model of body composition. Differences between methods appear to track within an individual. The individual-specific causes of these differences remain to be determined.

Mechanical Scale and Load Cell Underwater Weighing: A Comparison of Simultaneous Measurements and the Reliability of Methods

Both load cell and mechanical scale-based hydrostatic weighing (HW) systems are used for the measurement of underwater weight. However, there has been no direct comparison of the 2 methods. The purpose of the current investigation was to simultaneously compare a load cell and mechanical scale for use in HW. Twenty-seven men and women (mean ± SD, age: 22 ± 2 years) participated in the 2-day investigation. Each subject completed 2 HW assessments 24 hours apart. Single-day comparisons of all trials for both days revealed no significant difference between the mechanical scale and the load cell (mean difference < 0.016 kg, p > 0.05). True underwater weight values were not significantly different between methods for either days (mean difference < 0.014 kg, p > 0.05) and accounted for a mean difference in percent fat (%FAT) of <0.108%. The 95% limits of agreement indicated a maximum difference between methods of 0.53% FAT. Both methods produced similar reliability SEM values (mechanical SEM < 0.72%FAT, load cell SEM < 0.75%FAT). In conclusion, there was no difference between mechanical scale and load cell measurements of underwater weights and the added precision of the load cell only marginally (<0.16%FAT) improved day-to-day reliability. Either a mechanical scale or load cell can be used for HW with similar accuracy and reliability in young adults with a body mass index of 18.7-34.4 (5-25%FAT).

A proposed method for the evaluation of body fat in Japanese adults that predicts obesity

The present study was designed to develop a simple predictive equation for the percent body fat (%BF) in Japanese adults based on variables collected during health examinations. We hypothesized that a benchmark for defining metabolic syndrome and obesity could be based on %BF, which was measured by underwater weighing (UW) as a gold standard for body composition assessment. Thus, we developed a predictive equation for %BF derived from UW that may contribute to the assessment of obesity status, characterized by an excess accumulation of visceral or subcutaneous fat. The subjects were 810 Japanese participants (283 men, 527 women, ages 18-59 years). Anthropometric variables, including height, weight, 7 circumferences, and 8 skinfold thicknesses, were measured. The developed predictive equation was as follows: %BF = 10.558 × sex (1 for men; 2 for women) + 0.069 × age + 0.667 × body mass index + 0.314 × abdominal circumference - 35.881.The coefficient of determination (r(2)) was 0.69. The predicted %BF derived from this equation was highly correlated with UW-measured values and did not show underestimation or overestimation in either sex. These data suggested that this predictive equation for %BF can be used for all Japanese adults and does not require the use of medical equipment and special measurement techniques. By combining the equation for %BF developed in this study with a %BF cutoff value of metabolic syndrome and obesity (>25.0% in men and >30.0% in women), all Japanese adults can easily and conveniently assess obesity status.

Fluid and Diet Patterns Associated with Weight Cycling and Changes in Body Composition Assessed by Continuous Monitoring Throughout a College Wrestling Season

This study examined the methods used to meet certification weight for wrestling and to measure the changes in body composition during 1 season for Division III college wrestlers. Nine college wrestlers completed this study. Body composition was analyzed by underwater weighing (UWW) and multifrequency bioelectrical impedance before and throughout the competitive season. Hydration status was measured by urine osmolality (Uosm) and urine specific gravity (Usg). Nutritional intake was measured for 2 1-week periods, once at the beginning and again near the end of the season. Subjects' fat-free mass (FFM) increased an average of 1.8 kg, whereas fat mass (FM) decreased 2.2 kg as indicated by UWW from the beginning to the end of the season. Wrestlers on average cycled their weight 3.4 kg (4.7% of body weight) per week. The majority of wrestlers cut weight by reducing calories and restricting fluids starting 2 days before the competition. Uosm and body weights on Friday suggested that for wrestlers to achieve the necessary weight loss by dehydration to "make weight" for a Saturday meet, wrestlers would approach a 5% level of dehydration. No loss of FFM because of weight cycling (WC) was evident to achieve competitive weight. Most wrestlers significantly restricted fluids and caloric intake in the 48 hours before weigh-in.

Suscceptibility of Hydrostatic Weighing to Intentional Error in Weight Certification Use for Wrestlers

Suscceptibility of Hydrostatic Weighing to Intentional Error in Weight Certification Use for Wrestlers

Comparison of Various Methods of Measuring Body Composition to Underwater Weighing in Adult Men and Women

Comparison of Various Methods of Measuring Body Composition to Underwater Weighing in Adult Men and Women

Criterion Validity of the Air Displacement Plethysmography Technique in the Assessment of Percent Body Fat

The assessment of percent body fat (PBF) is important in the establishment of recommended body weight. For years, hydrostatic weighing (HW) was the "gold standard" to determine PBF. A relatively new technique to assess PBF is the air-displacement plethysmography (ADP) technique, commonly determined with the use of the BOD POD. While its validity has been reported in the literature, the results are conflicting. Preliminary data collected at Boise State University seemed to question the validity of ADP in the assessment of PBF. PURPOSE: The purpose of this investigation was to determine if there is a significant difference between PBF as determined through ADP and HW. METHODS: Eighty (n = 80) healthy male- and female-Caucasian subjects between the ages of 18 and 40 were tested for PBF using ADP and HW. The subjects were divided by gender and BMI into six groups: normal weight (NW), overweight (OW), and obese (OB) groups. Pearson's correlation was used to determine the relationship between ADP and HW and Repeated Measures ANOVA was used to determine if there were statistically significant differences between the two estimates of PBF. RESULTS: Overall, PBF obtained through ADP (25.6 ± 8.2%) was significantly higher as compared to HW (20.7 ± 8.4%). PBF results for NW, OW, and OB men respectively according to ADP and HW were: 16.3 vs. 11.4, 21.7 vs.17.7, and 34.2 vs. 30.7. For NW, OW, and OB women the respective results according to ADP and HW were: 26.9 vs. 20.5, 33.2 vs. 30.4, and 37.4 vs. 34.2. Strong positive correlations were found between ADP and HW for all groups in the assessment of PBF (r =.829 to.990). Significant differences (p <.05), however, were found between ADP and HW in every group except in the group of obese women. The latter result may be due to the low number of subjects in this group (n = 3). CONCLUSION: Based on these results, ADP cannot be accepted as an accurate technique to assess PBF in 18 to 40-year-old Caucasians. Further validation studies need to be conducted, with the possible development of correction factors based on PBF level, to make ADP an acceptable technique for PBF assessment.

Evaluation of Multifrequency Bioelectrical Impedance Analysis in Assessing Body Composition of Wrestlers

To evaluate the accuracy of multifrequency bioelectrical impedance analysis (MFBIA) in assessing fat-free mass (FFM) in comparison with hydrostatic weighing (HW) and skinfolds (SK) in high school wrestlers in a hydrated state. Body composition was determined by MFBIA, HW, and three-site SK in 72 high school wrestlers (mean +/- SD; age = 15.3 +/- 1.4 yr, height = 1.71 +/- 0.08 m, body mass = 67.3 +/- 13.4 kg). Hydration state was quantified by evaluating urine specific gravity. There were no significant differences for estimated FFM between MFBIA (57.2 +/- 9.5 kg) and HW (57.0 +/- 10.1 kg) or SK (56.4 +/- 8.8 kg). The SEE for FFM with HW as the reference method were 2.73 kg for MFBIA and 2.66 kg for SK. Correlations were found for FFM between HW and MFBIA (r = 0.96, P < 0.001) and between HW and SK (r = 0.97, P < 0.001). A systematic bias was found for MFBIA because the difference between MFBIA and HW correlated with the FFM average of the two methods (r = -0.22, P < 0.001). A bias was also seen between SK and HW and correlated with the FFM average (r = -0.47, P < 0.001). This study demonstrates that MFBIA provides similar estimates of FFM when compared with HW in a heterogeneous high school wrestling population during a hydrated state. MFBIA is an attractive assessment tool, easy to use, and may be considered as an alternative field-based method of estimating the FFM of high school wrestlers.

Validation of bioelectrical impedance analysis to hydrostatic weighing in male body builders

The purpose of this study was to compare bioelectrical impedance analysis (BIA) to hydrostatic weighing (HW) in male weight lifters and body builders. Twenty-two male body builders and weight lifters, 23 +/- 3 years of age (mean +/- SD), were studied to determine the efficacy of BIA to HW in this population. Subjects were measured on two separate occasions, 6 weeks apart, for test-retest reliability purposes. Participants recorded 3-day dietary intakes and average work-out times and regimens between the two testing periods. Subjects were, on average, 75 +/- 8 kg of body weight and 175 +/- 7 cm tall. Validation results were as follows: constant error for HW-BIA = 0.128 +/- 3.7%, r for HW versus BIA = -0.294. Standard error of the estimate for BIA = 2.32% and the total error for BIA = 3.6%. Percent body fat was 7.8 +/- 1% from BIA and 8.5 +/- 2% from HW (P > 0.05). Subjects consumed 3,217 +/- 1,027 kcals; 1,848 +/- 768 kcals from carbohydrates; 604 +/- 300 kcals from protein; and 783 +/- 369 kcals from fat. Although work-outs differed among one another, within subject training did not vary. These results suggest that measurement of percent body fat in male body builders and weight trainers is equally as accurate using BIA or HW.

Comparison of Body Composition Measurements using a New Caliper, Two Established Calipers, Hydrostatic Weighing, and BodPod

Purposes: (1) To compare the Lafayette Instruments (LI) skinfold caliper to the Lange (L) and Harpenden (H) calipers using a diverse subject population. (2) To determine the validity of the LI caliper in a subset of subjects by comparing body compositions from skinfold thicknesses to those measured by hydrostatic weighing (HW) and air displacement plethysmography (ADP). (3) To compare measurements obtained by experienced (EX) and inexperienced (IX) technicians using all three calipers. Methods: Skinfold measurements were performed by both EX and IX technicians using three different calipers on 21 younger (21.2 ± 1.5 yrs) and 20 older (59.2 ± 4 yrs) subjects. Body compositions were calculated using the Jackson-Pollock seven-site and three-site formulas. HW and ADP tests were performed on a subset of subjects (10 younger, 10 older). Results: No significant differences existed between LI and L or H when measurements were made by EX. Further, the LI-EX measurements were highly correlated to both H-EX and L-EX. No significant differences existed in the subgroup between LI-EX and HW or ADP. Skinfold determinations made by EX and IX were similar. Conclusions: Similar body compositions determined using LI, H, and L suggest that LI determines body composition as effectively as H and L. High correlations between the three calipers support this notion. Similar results between LI and HW/ADP subgroup suggest that the LI caliper may be a valid method of measuring body composition. Overall, performance by IX was similar to EX and suggests similar ease of use for all three calipers.

Comparison of Results of the Volume Determination of Mass Standards by Weighings in Air and Conventional Hydrostatic Weighing Method

Two methods for the volume determination of mass standards are compared. The conventional hydrostatic weighing method where the mass standards are immersed in water and weighings in air where the m...

Evaluation of the BOD POD for Estimating Percent Body Fat in Collegiate Track and Field Female Athletes: A Comparison of Four Methods

This investigation examined the accuracy of the BOD POD on a group of Division I collegiate track and field female athletes (N = 30). Hydrostatic weighing (HW) was used as the gold standard method. Body density (Db) values obtained from the BOD POD (Db BP) were compared with those determined by HW (Db HW). Both Db values were converted to percent body fat (%BF) using the Siri equation for comparison. Percent body fat values obtained from the BOD POD (BF BP) were also compared with those obtained from dual-energy X-ray absorptiometry (DXA, BF DXA) and skinfold (SF, BF SF). The validity of the BOD POD was assessed using repeated-measures analysis of variance (ANOVA), and the relationship between the methods was examined through Pearson correlation. Average Db BP was 0.00890 g x cm(-3) lower (p < 0.05) than Db HW, resulting in a significant overestimation of %BF (p < 0.05) by the BOD POD. Values for BFDXA and BFBP also differed significantly (p < 0.05). On the other hand, BFSF and BF BP were not significantly different. The correlation between percent body fat values obtained from HW (BFHW) and BF BP was good (r = 0.88, SEE = 2.30) as well as between BF SF and BF BP (r = 0.85, SEE = 2.05). Conversely, the correlation between BFDXA and BF BP was poor (r = 0.25, SEE = 5.73). The strong correlation between BF BP and BF HW presented here suggests that the BOD POD has the potential to be used as a body composition analysis tool for female athletes. The advantages of the BOD POD over HW encourage further investigation of this instrument. However, the fact that the BOD POD and SF results did not differ significantly might suggest that the SF could be used in its place until a better rate of accuracy for this instrument is established.

Estimating body fat in NCAA Division I female athletes: a five-compartment model validation of laboratory methods

The purpose of the present study was to determine the validity of various laboratory methods for estimating percent body fat (%fat) in NCAA Division I college female athletes (n = 29; 20 +/- 1 year). Body composition was assessed via hydrostatic weighing (HW), air displacement plethysmography (ADP), and dual-energy X-ray absorptiometry (DXA), and estimates of %fat derived using 4-compartment (C), 3C, and 2C models were compared to a criterion 5C model that included bone mineral content, body volume (BV), total body water, and soft tissue mineral. The Wang-4C and the Siri-3C models produced nearly identical values compared to the 5C model (r > 0.99, total error (TE) < 0.40%fat). For the remaining laboratory methods, constant error values (CE) ranged from -0.04%fat (HW-Siri) to -3.71%fat (DXA); r values ranged from 0.89 (ADP-Siri, ADP-Brozek) to 0.93 (DXA); standard error of estimate values ranged from 1.78%fat (DXA) to 2.19%fat (ADP-Siri, ADP-Brozek); and TE values ranged from 2.22%fat (HW-Brozek) to 4.90%fat (DXA). The limits of agreement for DXA (-10.10 to 2.68%fat) were the largest with a significant trend of -0.43 (P < 0.05). With the exception of DXA, all of the equations resulted in acceptable TE values (<3.08%fat). However, the results for individual estimates of %fat using the Brozek equation indicated that the 2C models that derived BV from ADP and HW overestimated (5.38, 3.65%) and underestimated (5.19, 4.88%) %fat, respectively. The acceptable TE values for both HW and ADP suggest that these methods are valid for estimating %fat in college female athletes; however, the Wang-4C and Siri-3C models should be used to identify individual estimates of %fat in this population.

Validity and reliability of body composition analysers in children and adults

We tested the validity and reliability of the BioSpace InBody 320, Omron and Bod-eComm body composition devices in men and women (n 254; 21-80 years) and boys and girls (n 117; 10-17 years). We analysed percentage body fat (%BF) and compared the results with dual-energy X-ray absorptiometry (DEXA) in adults and compared the results of the InBody with underwater weighing (UW) in children. All body composition devices were correlated (r 0.54-0.97; P< or =0.010) to DEXA except the Bod-eComm in women aged 71-80 years (r 0.54; P=0.106). In girls, the InBody %BF was correlated with UW (r 0.79; P< or =0.010); however, a more moderate correlation (r 0.69; P< or =0.010) existed in boys. Bland-Altman plots indicated that all body composition devices underestimated %BF in adults (1.0-4.8 %) and overestimated %BF in children (0.3-2.3 %). Lastly, independent t tests revealed that the mean %BF assessed by the Bod-eComm in women (aged 51-60 and 71-80 years) and in the Omron (age 18-35 years) were significantly different compared with DEXA (P< or =0.010). In men, the Omron (aged 18-35 years), and the InBody (aged 36-50 years) were significantly different compared with DEXA (P=0.025; P=0.040 respectively). In addition, independent t tests indicated that the InBody mean %BF in girls aged 10-17 years was significantly different from UW (P=0.001). Pearson's correlation analyses demonstrated that the Bod-eComm (men and women) and Omron (women) had significant mean differences compared with the reference criterion; therefore, the %BF output from these two devices should be interpreted with caution. The repeatability of each body composition device was supported by small CV (<3.0 %).

Evaluation of Ultrasound in Assessing Body Composition of High School Wrestlers

To evaluate the accuracy of ultrasound (ULTRA) in assessing fat-free mass (FFM) in comparison with hydrostatic weighing (HW) and skinfolds (SK) in high school wrestlers in a hydrated state. Body composition was determined by ULTRA, HW, and three-site SK in 70 high school wrestlers (mean +/- SD: age, 15.5 +/- 1.5; height, 1.60 +/- 0.08 m; body mass, 65.8 +/- 12.7 kg). For all methods, body density (Db) was converted to percent body fat (%BF) using the Brozek equation. Hydration state was quantified by evaluating urine specific gravity. There were no significant differences for estimated FFM between ULTRA (57.2 +/- 9.7 kg) and HW (57.0 +/- 9.9 kg); however, SK (54.9 +/- 8.8 kg) were significantly different from HW. The standard errors of estimate for FFM with HW as the reference method were 2.40 kg for ULTRA and 2.74 kg for SK. Significant correlations were found for FFM between HW and ULTRA (r = 0.97, P < 0.001) and between HW and SK (r = 0.96, P < 0.001). A systematic bias was found for SK, as the difference between SK and HW significantly correlated with the FFM average of the two methods (r = -0.38, P < 0.001). This systematic bias was not found for ULTRA (r = - 0.07). This study demonstrates that ULTRA provides similar estimates of FFM when compared with HW in a heterogeneous high school wrestling population during a hydrated state. ULTRA should be considered as an alternative field-based method of estimating the FFM of high school wrestlers.

Comparison of Six Methods of Estimating Percent Body Fat to DXA in College Students

PURPOSE: To compare 6 methods of estimating percent body fat (%BF) to dualenergy x-ray absorptiometry (DXA). METHODS: Fifty college students volunteered to have %BF measured on 1 day by a self-administered skinfold caliper (SA), 3-site digital body fat caliper (DBF), handheld bioelectrical impedance analysis (BIA) device, leg-to-leg BIA device, sum of 3 skinfolds using the Brozek equation (Sum3B), and body mass index %BF (BMI%F) using the Gallagher et al. %BF prediction equation. All %BF values were compared to DXA %BF. The correlation coefficient (r), constant error (CE), standard error of the estimate (SEE), and total error (TE) were determined by comparison to DXA. RESULTS:TABLE 1: Men's (n = 25) data.TABLE 2: Women's (n = 25) data.CONCLUSION: Leg-to-leg BIA and BMI%F for men were similar to DXA %BF. Estimations of %BF from other devices were valid, but not accurate compared to DXA %BF. Previous research indicates that DXA overpredicts %BF compared to hydrostatic weighing (HW). Since most of the %BF methods other than DXA are based on data from HW, a correction equation may be warranted for comparison of data.

Percent body fat estimations in college men using field and laboratory methods: a three-compartment model approach.

BackgroundMethods used to estimate percent body fat can be classified as a laboratory or field technique. However, the validity of these methods compared to multiple-compartment models has not been fully established. The purpose of this study was to determine the validity of field and laboratory methods for estimating percent fat (%fat) in healthy college-age men compared to the Siri three-compartment model (3C).MethodsThirty-one Caucasian men (22.5 ± 2.7 yrs; 175.6 ± 6.3 cm; 76.4 ± 10.3 kg) had their %fat estimated by bioelectrical impedance analysis (BIA) using the BodyGram™ computer program (BIA-AK) and population-specific equation (BIA-Lohman), near-infrared interactance (NIR) (Futrex® 6100/XL), four circumference-based military equations [Marine Corps (MC), Navy and Air Force (NAF), Army (A), and Friedl], air-displacement plethysmography (BP), and hydrostatic weighing (HW).ResultsAll circumference-based military equations (MC = 4.7% fat, NAF = 5.2% fat, A = 4.7% fat, Friedl = 4.7% fat) along with NIR (NIR = 5.1% fat) produced an unacceptable total error (TE). Both laboratory methods produced acceptable TE values (HW = 2.5% fat; BP = 2.7% fat). The BIA-AK, and BIA-Lohman field methods produced acceptable TE values (2.1% fat). A significant difference was observed for the MC and NAF equations compared to both the 3C model and HW (p < 0.006).ConclusionResults indicate that the BP and HW are valid laboratory methods when compared to the 3C model to estimate %fat in college-age Caucasian men. When the use of a laboratory method is not feasible, BIA-AK, and BIA-Lohman are acceptable field methods to estimate %fat in this population.

Validity of the BOD POD for Assessing Body Composition in Athletic High School Boys

The purpose of this study was to validate the percentage of body fat (%BF) values estimated from the BOD POD (BP) with those obtained from hydrostatic weighing (HW) in athletic American high school boys. Additionally, the %BF values measured via near-infrared interactance (NIR), bioelectrical impedance (BIA), and skinfold (SF) were compared to HW to determine the validity of these measures. Thirty white boys (mean age +/- SD = 15.8 +/- 1.0 years) who where currently participating in organized sports volunteered to have their %BF estimated. Measurements were obtained from NIR, BP, BIA, and SF in random order and concluded with HW. The findings from the present study indicated that the NIR and BIA instruments produced significant (P < 0.008) constant error (CE) and total error (TE) values that were too large to be of practical value (TE > 4.0%BF). The BP produced a significantly (P < 0.008) higher CE with acceptable TE values compared to HW, but compared to all three SF estimations, the BP TE values were higher. Two of the SF equations were nonsignificant (P > 0.008) and had the lowest TE values compared to HW. These data suggest that the BP can produce acceptable body fat measures for athletic white boys but is not superior to estimates made by the SF equations used in this study.

DXA Provides a Valid Minimum Weight in Wrestlers

To cross-validate the DXA prediction of minimum weight (MW) in high school wrestlers, using a criterion-referenced analysis. The goal was to independently evaluate whether DXA provided a MW within acceptable limits for the sport of wrestling. Secondarily, the DXA prediction error was compared against the currently approved skinfold (SF) method. Criterion MW was calculated by hydrostatic weighing (HW) with measured residual lung volume. Whole-body scans were performed with a Norland XR-36 bone densitometer. All skinfolds were taken by the same experienced measurer. The subject's body density was computed by Lohman and was converted to percent body fat, using the equation of Brozek et al. The measured fat-free mass was used to calculate each wrestler's MW at 7% body fat. Subjects were 94 Wisconsin high school wrestlers (mean (SD): age = 15.1 yr (1.2), height = 170.3 cm (7.1), weight = 63.2 kg (9.6). There was no significant difference in mean MW from DXA (60.6 kg (9.0)) and the HW criterion (59.8 kg (9.0)). The correlation was strong (r = 0.98), and the regression for the relationship between HW and DXA (y = 0.976 x DXA + 0.698 kg) did not significantly deviate from the line of identity. A low standard error of estimate (SEE) of 1.7 kg and a pure error (PE) of 1.9 kg were found, with residuals ranging from -3.94 to 2.88 kg. This PE was similar to the SF method (2.1 kg) in the sample. Bland-Altman analysis showed no systematic bias in the prediction of MW across weight classes. We conclude that DXA provided a valid prediction of MW in this sample of high school wrestlers.

Percent body fat estimations in college women using field and laboratory methods: a three-compartment model approach.

BackgroundMethods used to estimate percent body fat can be classified as a laboratory or field technique. However, the validity of these methods compared to multiple-compartment models has not been fully established. This investigation sought to determine the validity of field and laboratory methods for estimating percent fat (%fat) in healthy college-age women compared to the Siri three-compartment model (3C).MethodsThirty Caucasian women (21.1 ± 1.5 yrs; 164.8 ± 4.7 cm; 61.2 ± 6.8 kg) had their %fat estimated by BIA using the BodyGram™ computer program (BIA-AK) and population-specific equation (BIA-Lohman), NIR (Futrex® 6100/XL), a quadratic (SF3JPW) and linear (SF3WB) skinfold equation, air-displacement plethysmography (BP), and hydrostatic weighing (HW).ResultsAll methods produced acceptable total error (TE) values compared to the 3C model. Both laboratory methods produced similar TE values (HW, TE = 2.4%fat; BP, TE = 2.3%fat) when compared to the 3C model, though a significant constant error (CE) was detected for HW (1.5%fat, p ≤ 0.006). The field methods produced acceptable TE values ranging from 1.8 – 3.8 %fat. BIA-AK (TE = 1.8%fat) yielded the lowest TE among the field methods, while BIA-Lohman (TE = 2.1%fat) and NIR (TE = 2.7%fat) produced lower TE values than both skinfold equations (TE > 2.7%fat) compared to the 3C model. Additionally, the SF3JPW %fat estimation equation resulted in a significant CE (2.6%fat, p ≤ 0.007).ConclusionData suggest that the BP and HW are valid laboratory methods when compared to the 3C model to estimate %fat in college-age Caucasian women. When the use of a laboratory method is not feasible, NIR, BIA-AK, BIA-Lohman, SF3JPW, and SF3WB are acceptable field methods to estimate %fat in this population.