Validity and Reliability Analysis Among Three Different Fat Assessment Methods in Trained Indian Male Athletes

PURPOSE: To compare bioelectrical impedance analysis (BIA) and air displacement plethysmography (ADP) for body composition assessment in female collegiate athletes. METHODS: Retrospective review of body composition data for 61 NCAA female collegiate athletes (basketball n = 14, soccer n = 31, volleyball n = 16), measured by BIA and ADP on the same day. Paired t-tests, effect size using Cohen’s d, Pearson’s correlation, and Bland-Altman plots were used to compare percent body fat (%BF) and fat-free mass (FFM) measurements from BIA and ADP for the whole sample, and within sports. RESULTS: The sample included 61 female athletes ages 18-25 years (x̅ = 19.5 ± 1.4 years), with heights ranging from 160-190.5 cm (x̅ = 172.3 ± 8.9 cm), %BF measures ranging from 6.0-38.5% (x̅ = 21.3 ± 6.3%) for ADP and 13.4-36.0% for BIA (x̅ = 22.5 ± 4.7%) and FFM measures ranging from 36.2-69.3 kg (x̅ = 53.4 ± 6.8 kg) for ADP, and 38.8-63.8 kg for BIA (x̅ = 52.4 ± 5.8 kg). Overall, BIA and ADP had strong positive correlations for %BF (r = 0.67) and FFM (r = 0.891). BIA significantly underestimated FFM when compared to ADP (mean difference [MD] = -0.99 kg, p = 0.016, d = -0.32), while no significant difference was observed in %BF (MD = 1.17%, p = 0.056, d = 0.25). Linear regression on the Bland-Altman plots revealed small but significant negative trends for both %BF (β = -0.34, p = 0.004) and FFM (β = -0.166, p = 0.01) estimation by BIA in the total sample. This indicates possible proportional bias, in which BIA is more likely to overestimate %BF and FFM at low values, and underestimate %BF and FFM at high values. When comparing sports, BIA significantly overestimated %BF (MD = 5.42%, p = 0.001, d = 1.14) and underestimated FFM (MD = -3.71 kg, p = 0.001, d = -1.07) for basketball players and significantly underestimated %BF (MD = -2.06%, p = 0.04, d = -0.56) in volleyball players, when compared to ADP. No significant measurement differences were found in soccer players. CONCLUSIONS: BIA gives comparable body composition results to ADP for soccer players, but gives conflicting results regarding over and underestimation of %BF and FFM in basketball and volleyball players. Conflicting conclusions based on sport may indicate the need for specialized equations when extrapolating body composition measures using BIA for athletes at the higher and lower ends of the spectrum of %BF and FFM.

Patients with end-stage renal disease (ESRD) have significant shifts in fluid homeostasis that may impair measurements of body composition using methods based upon determinations of body water. Estimates of body water are fundamental for bioelectrical impedance analysis (BIA), which measures electrical resistance to estimate total body water and body composition. BIA was compared with 2 other techniques: (1) air displacement plethysmography (ADP), which relies on measurements of body density to estimate body fat and fat-free masses; and (2) dual-energy x-ray absorptiometry (DXA), which depends on the relative attenuation of an x-ray beam to produce images of body fat and bone mineral. In study 1, BIA and ADP were performed on 38 ESRD patients (21 men and 17 women; age 51.3 +/- 2.2 years; weight 79.8 +/- 2.9 kg; body mass index [BMI] 27.4 +/- 0.9 kg/m2). In study 2, BIA and DXA were performed on 47 patients (22 men and 25 women; age 52.7 +/- 2.3 years; weight 73.6 +/- 2.9 kg; BMI 25.9 +/- 1.0 kg/m2). The ranges of percent body fat using BIA in studies 1 and 2 were from 7% to 57% and from 6% to 52%, respectively. Percent body fat measurements were significantly (p < .0001) correlated for BIA vs ADP (r = .74) and for BIA vs DXA (r = .84). Mean body fat as determined by BIA and ADP in study 1 was 31.8 +/- 2.0% and 36.3 +/- 1.8%* and by BIA and DXA in study 2 was 29.6 +/- 1.5% and 31.8 +/- 1.8%*, respectively (*p < .05 vs BIA). All 3 methods had similar variability associated with their measurements (coefficients of variation approximately 5%). The average body fat measured by BIA was less than ADP or DXA, regardless of gender or race. Furthermore, the variation was not greater at lower or higher body fat values. Body fat measurements using ADP and DXA were correlated with those using BIA across a relatively wide range of body fat levels in adults with ESRD. However, BIA appeared to underestimate body fat and overestimate fat-free mass, possibly because of increased measurements of body water. Because ADP is convenient and does not use body water content in determination of body density and body composition, it has very good potential as a relatively new technique to estimate percent body fat in adults with ESRD.

Body composition in COPD; stepping back or moving forward?

Bioelectrical Impedance Analysis and Skinfold Thickness Sum in Assessing Body Fat Mass of Renal Dialysis Patients

Body composition is a highly important metric in regards to overall physical activity as well as sports performance. Most body fat percentage (BF%) measurements are recorded using two-compartment models, such as skinfold analyses, bioelectrical impedance analysis, or more accurately, via hydrostatic weighing or air displacement plethysmography (ADP). However, research has suggested that three-compartment models, like dual energy x-ray absorptiometry (DEXA), may provide more accurate recordings of BF%. However, limited research exists in comparing BF% obtained via two- and three-compartment models in collegiate athletes. PURPOSE: To compare BF% recordings via DEXA and ADP in Division-I collegiate male and female athletes. METHODS: Seventy-eight athletes (Male: n = 45 [age = 18.4 ± 1.0 y, height = 161.9 ± 55.5 cm, weight = 77.3 ± 32.5 kg]; Female: n = 33 [age = 18.0 ± 0.7 y, height = 146.3 ± 56.9 cm, weight = 55.9 ± 23.8 kg]) from multiple sports underwent BF% testing via DEXA and ADP. Both tests were completed on the same visit under supervision by the same test administrator. Hydration status was measured before testing to ensure that all athletes were properly hydrated prior to the test. Athletes were instructed to dress in accordance to the recommended protocols for both tests. Individual paired sample t-tests were run for BF% comparisons for whole group, male athletes, and female athletes. RESULTS: A significant mean difference existed for all athletes between DEXA (21.6 ± 10.3%) and ADP (16.4 ± 9.2%) when comparing BF% (p < 0.01, ES = 0.53). When factored for gender, male BF% exhibited a significant mean difference between DEXA (16.3 ± 9.5%) and ADP (11.8 ± 8.0%) (p < 0.01, ES = 0.51). Additionally, a significant mean difference for BF% was found in the female athletes between DEXA (28.5 ± 6.6%) and ADP (22.2 ± 7.1%) (p < 0.01, ES = 0.92). CONCLUSION: These results, which are consistent with previous research, indicate significantly greater BF% values for DEXA when comparing athletic populations.

Aim To determine the validity of bioelectrical impedance analysis (BIA) in quantifying fat-free mass (FFM) compared to air-displacement plethysmography (ADP) in patients with a motor neurone disease (MND). Methods FFM of 140 patients diagnosed with MND was determined by ADP using the BodPod (i.e. the gold standard), and by BIA using the whole-body Bodystat. FFM values were translated to predicted resting energy expenditure (REE); the actual REE was measured using indirect calorimetry, resulting in a metabolic index. Validity of the BIA compared to the ADP was assessed using Bland-Altman analysis and Pearson’s r. To assess the clinical relevance of differences, we evaluated changes in metabolic index and in individualized protein demand. Results Despite the high correlation between ADP and BIA (r = 0.93), averaged across patients, the assessed mean fat-free mass was 51.7 kg (± 0.9) using ADP and 54.2 kg (± 1.0) using BIA. Hence, BIA overestimated fat-free mass by 2.5 kg (95% CI 1.8–3.2, p < 0.001). Clinically, an increased metabolic index would be more often underdiagnosed in patients with MND using BIA (31.4% according to BIA versus 44.2% according to ADP, p = 0.048). A clinically relevant overestimation of ≥ 15 g in protein demand was observed for 4 (2.9%) patients using BIA. Conclusions BIA systematically overestimates FFM in patients with MND. Although the differences are limited with ADP, underscoring the utility of BIA for research, overestimation of fat-free mass may have consequences for clinical decision-making, especially when interest lies in determining the metabolic index.

Body composition (BC) is considered to be an important component of fitness testing, and accurate assessment of one’s BC is critical to determining that person’s general level of fitness, as well as their risk for cardiovascular disease. There are numerous methods to assess BC, but a relatively new technique, called Integrative Body Composition (IBC), has been developed using a person’s height (H), weight (W), waist circumference (WAIST), and wrist diameter (WD). This method has been validated previously against other BC assessment methods, such as hydrostatic weighing (HW) and air displacement plethysmography (ADP), but it has not been tested using dual-energy x-ray absorptiometry (DXA) as the criterion measure. PURPOSE: To investigate the validity of the IBC method for assessing a person’s BC using DXA as the criterion measure. For comparison purposes, data from skinfolds (SF) and from bioelectrical impedance analysis (BIA) were also collected. METHODS: A convenience sample of sixty participants (Males n=24; Females n=36) reported twice to the lab, once where H, W, WAIST, and WD data were collected for IBC assessment, as well as data for SF and BIA, and a second time where data from DXA were collected. RESULTS: Mean percent body fat values for the four assessment methods were as follows: [IBC (Total: 25.3 ± 8.5; Males: 20.6 ± 8.4; Females: 28.5 ± 6.9); DXA (Total: 28 ± 7.2; Males: 23.9 ± 6.6; Females: 30.8 ± 6.2); SF (Total: 21.1 ± 8.3; Males: 17.1 ± 6.8; Females: 23.9 ± 8.1); BIA (Total: 22.2 ± 8.2; Males: 18.8 ± 8.8; Females: 24.6 ± 6.8)]. Pearson correlations revealed significant relationships (p<0.01) between IBC & DXA (Total: r=0.81; Males: r=0.77; Females: r=0.74), IBC & SF (Total: r=0.84; Males: r=0.81; Females: r=0.83), and IBC & BIA (Total: r=0.83; Males: r=0.78; Females: r=0.82). CONCLUSIONS: Consistent with previous research identifying IBC as a valid measure when compared to HW and ADP, these data support IBC as a valid BC assessment technique when also compared to DXA. However, it should be noted that the standard deviations in these data were fairly large, and that these data as well as previously collected data on IBC are limited to correlational values. Additional analyses of these data should be conducted to determine the magnitude of agreement between these assessment methods.

To determine the level of agreement between measurements of body composition by air-displacement plethysmography (ADP) and bioelectrical impedance analysis (BIA) in obese/non-obese children and adolescents. Fat mass (FM) and fat free mass (FFM) were measured by ADP using the BOD-POD system and foot-to-foot BIA in 187 children and adolescents (75 males and 112 females, aged 5 to 22 years). Obesity was defined as a percentage FM (determined by BOD-POD), as a percentage (%) higher than 25%-35%. Sixty-four subjects were obese and 123 non-obese. Lin's Concordance Coefficient (Rc) between estimates of FM (%) and FFM (kg) was 0.79 (95% CI: 0.73; 0.83) by BIA and 0.96 (95% CI: 0.95; 0.97) by ADP. For the group of patients as a whole, the mean difference (p < 0.001) between methods (the BIA measurement minus the ADP measurement) was -3.39 (95% CI: -4.13; -2.65) for FM (%) and 1.54 (95% CI: 1.10; 1.98) for FFM (kg) (p < 0.001). The limits of agreement were -13.70; 6.90 for FM (%) and 1.40; 7.60 for FFM (kg). In the obese group, the mean difference between methods was -5.01 (95% CI: -6.21; -3.81) for FM (%) and 2.58 (95% CI: 3.45; 1.71) for FFM (kg) (p < 0.001). In the non-obese group, these mean differences were 2.49 (95% CI: -3.41; -1.57) and 0.96 (95% CI: 1.43; 0.50), respectively (p < 0.001). Compared with ADP, foot-to-foot BIA overestimates FFM and underestimates FM in obese and non-obese children of either sex. ADP and BIA estimates of FFM and FM are highly correlated for both obese/non-obese children. However, the large limits of agreement suggest that these methods should not be used interchangeably.

Body composition is an important nutritional status indicator among preterm infants, but is challenging to measure in the neonatal intensive care unit (NICU). Bioelectrical impedance analysis (BIA) is highly feasible, but accuracy depends on using a valid prediction equation. We aimed to evaluate the accuracy of available prediction equations, relative to air displacement plethysmography (ADP) as the criterion method, within a cohort of hospitalized preterm infants. Preterm infants (23-35 weeks' gestation) underwent concurrent BIA and ADP up to three times between birth and term equivalent age. Using 11 published prediction equations, we estimated infant body composition from BIA data. To determine validity, we used Bland-Altman plots to compare BIA-derived fat-free mass (FFM) with FFM measured concurrently by ADP. One hundred and fifteen infants, with a median 30 6/7 weeks' gestation, underwent 150 instances of concurrent BIA and ADP at ages 1 to 135 (median: 40) days. Agreement between BIA and ADP-derived FFM varied widely depending on the BIA equation used, with mean bias (±95% confidence limits) ranging from 0.14 (±0.24) to 1.34 (±1.51) kg. The Dung, Lingwood, and Tint equations demonstrated the greatest agreement with ADP, with a mean bias of 0.14-0.32 kg and narrow limits of agreement (±0.23-0.28 kg). All equations demonstrated some bias. BIA is a feasible tool for measuring body composition among preterm infants. Existing published equations demonstrate reasonable agreement with ADP but require a correction factor to adjust for bias. A novel prediction equation specific to preterm infants might offer improved agreement and reduced bias.

Nickerson, BS, Snarr, RL, and Ryan, GA. Validity of foot-to-foot bioelectrical impedance for estimating body composition in NCAA Division I male athletes: A 3-compartment model comparison. J Strength Cond Res 33(12): 3361-3366, 2019-The purpose of this study was to validate single-frequency foot-to-foot bioelectrical impedance analysis (FF-BIA) against a 3-compartment (3C) model in NCAA Division I male athletes. Thirty-three athletes (football = 19, baseball = 8, basketball = 3, and cheerleading = 3) had body fat percentages (BF%) and fat-free mass (FFM) estimated using a 3C model and FF-BIA. The criterion 3C model was derived from body mass, body volume (air displacement plethysmography), and total body water (bioimpedance spectroscopy). The mean BF% and FFM values for FF-BIA were not statistically significant when compared with the 3C model (p = 0.14 and 0.28, respectively). The standard error of estimate (2.79% and 2.64 kg), total error (2.95% and 2.64 kg), and 95% limits of agreement (±5.67% and ±5.15 kg) were considered acceptable for BF% and FFM, respectively. However, there was a significant trend in the regression line of the Bland-Altman plot, which indicated proportional bias for BF% (r = -0.50; p < 0.01). No proportional bias was present for FFM (r = 0.26; p > 0.05). Foot-to-foot BIA seems to be valid for estimating group and individual athlete's FFM. Similarly, FF-BIA can be used for estimating group BF%. However, proportional bias indicates that FF-BIA is not valid for individual estimates of BF%.

This study investigated the comparability between air displacement plethysmography (ADP), dual-energy X-ray absorptiometry (DXA), and bioelectrical impedance analysis (BIA) methods for body composition assessment and their correlations with physical performance in rugby players. Nineteen male elite players participated in the study. ADP, DXA, and BIA were used to assess fat-mass and fat-free mass. Physical performance was assessed by means of Carminatti's test of peak velocity (PVTCAR), countermovement jump (CMJ), sprint speed (10 and 30-m), and match performance analyses (sprinting, distance covered, and high-intensity running). BIA overestimated fat-mass (13±41%; r2=0.60) and underestimated fat-free mass (-1±7%; r2=0.66) compared to ADP (P=0.001). BIA underestimated fat-mass (-28±3%; r2=0.92) and overestimated fat-free mass (10±5%; r2=0.87) compared to DXA (P<0.001). ADP underestimated fat-mass (-36±37%; r2=0.69) and overestimated fat-free mass (11±8%; r2=0.52) compared to DXA (P<0.001). Fat-mass measured by ADP, DXA, and BIA negatively correlated with PVTCAR (r2≥0.49), height and peak power from CMJ (r2≥0.30), sprinting ability (r2≥0.65), and match performance variables (r2≥0.30). As long as one considers that ADP and BIA underestimated fat-mass and overestimated fat-free mass compared to DXA, the methods can be used to estimate body composition, particularly to track body fat-mass changes, which negatively influence several physical capacities determinant to rugby performance. The limitations of the methods should be borne in mind when assessing the body composition of rugby athletes.

To examine the intermethods agreement of dual-energy X-ray absorptiometry (DXA) and foot-to-foot bioelectrical impedance analysis (BIA) to assess the percentage of body fat (%BF) in young male athletes using air-displacement plethysmography (ADP) as the reference method. Standard measurement protocols were carried out in 104 athletes (40 swimmers, 37 footballers, and 27 cyclists, aged 12-14 y). Age-adjusted %BF ADP and %BF BIA were significantly higher in swimmers than footballers. ADP correlates better with DXA than with BIA (r = .84 vs r = .60, P < .001). %BF was lower when measured by DXA and BIA than ADP (P < .001), and the bias was higher when comparing ADP versus BIA than ADP versus DXA. The intraclass correlation coefficients between DXA and ADP showed a good to excellent agreement (r = .67-.79), though it was poor when BIA was compared with ADP (r = .26-.49). The ranges of agreement were wider when comparing BIA with ADP than DXA with ADP. DXA and BIA seem to underestimate %BF in young male athletes compared with ADP. Furthermore, the bias significantly increases with %BF in the BIA measurements. At the individual level, BIA and DXA do not seem to predict %BF precisely compared with ADP in young athletic populations.

Hormonal-induced water retention during the menstrual cycle (MC) may affect the estimates of body composition (BC) parameters depending on the MC phase if tissue hydration or volume is part of the BC analysis equations. Given this, MC phase-dependent changes of BC parameters might be expected within females for bioelectrical impedance analysis (BIA) or air-displacement plethysmography (ADP), whereas skin-fold calipometry (CAL) might not be affected. This study aimed to evaluate BC analyses during a regular MC by means of BIA and ADP with CAL serving as a control method in females with or without hormonal contraception with males serving as a control group. In a case-control design with repeated measurements, BC was determined using BIA, ADP, and CAL in 54 participants (age 18-33; BMI 17.0-27.8) divided into females using hormonal contraceptives (HC) (n=19), females using no-hormonal contraceptives (no-HC) (n=17), and males (n=18). BC was assessed on four cycle-related days (menstruation, late follicular, ovulation, and late luteal). There were only small intraindividual BC variations during the MC (CV% 0.5-5.2) and neither significant time effects within any group (p=0.065-0.939) nor significant time*group interactions (p=0.151-0.956) for all devices (BIA, ADP, CAL) in any BC parameter. The results indicate that hormonal-induced water retention, if any, during MC had no effect on BC estimates of ADP, BIA, and CAL or were too small to be identified neither in females with HC nor in females with no-HC.

The purpose of the present study was twofold: firstly, to assess the reliability of various body composition methods, and secondly, to determine the ability of the methods to estimate changes in fat-free mass (FFM) following creatine (Cr) supplementation. Fifty-five healthy male athletes (weight 78.3 +/- 10.3 kg, age 21 +/- 1 years) gave informed consent to participate in this study. Subjects' FFM was estimated by hydrostatic weighing (HW), air-displacement plethysmography (ADP), bioelectrical impedance analysis (BIA), near-infrared spectroscopy (NIR), and anthropometric measurements (ANTHRO). Measurements were taken on 2 occasions separated by 7 days to assess the reliability of the methods. Following this, 30 subjects returned to the laboratory for an additional test day following 7 days of Cr supplementation (20 g.d(-1) Cr + 140 g.d(-1) dextrose) to assess each method's ability to detect acute changes in FFM. In terms of reliability, we found excellent test-retest correlations for all 5 methods, ranging from 0.983 to 0.998 (p < 0.001). The mean biases for the 5 methods were close to 0 (range -0.1 to 0.3 kg) and their 95% limits of agreement (LOAs) were within acceptable limits (HW = -1.1 to 1.7 kg; ADP = -1.1 to 1.2 kg; BIA = -1.0 to 1.0 kg; NIR = -1.4 to 1.4 kg); however, the 95% LOAs were slightly wider for ANTHRO (-2.4 to 2.6 kg). Following Cr supplementation there was a significant increase in body mass (from 77.9 +/- 10.1 kg to 78.9 +/- 10.3 kg, p = 0.000). In addition, all 5 body composition techniques detected the change in FFM to a similar degree (mean change: HW = 0.9 +/- 0.6 kg; ADP = 0.9 +/- 0.6 kg; BIA = 0.9 +/- 0.6 kg; NIR = 0.8 +/- 0.5 kg; ANTHRO = 1.0 +/- 0.7 kg; intraclass correlation coefficient = 0.962). We conclude that between-day differences in FFM estimation were within acceptable limits, with the possible exception of ANTHRO. In addition, all 5 methods provided similar measures of FFM change during acute Cr supplementation.

Commercially available upper-body (UB) and lower-body (LB) bioelectrical impedance analyzers (BIA) are commonly used to measure body fat percentage (%BF) and classify body composition status. Some evidence suggests that LB BIA underestimate %BF specifically in women. It is not clear if UB BIA devices also underestimate %BF in women or if LB and UB BIA devices underestimate %BF in men. PURPOSE: To compare %BF from air displacement plethysmography (ADP), UB BIA, LB BIA, and whole-body (WB) BIA and to determine if the %BF differences between devices are affected by sex. METHODS: 53 women (21±5 yrs) and 42 men (23±5 yrs) had their %BF measured via ADP, a hand-held UB BIA, a digital scale LB BIA, and a validated eight-electrode multifrequency WB BIA device following each device’s recommended procedures. Paired samples t-tests were used to compare %BF between devices within each sex. Independent samples t-tests were used to compare the %BF difference between devices for each sex. RESULTS: In women, UB (23.8±4.3%) and LB (20.4±5.8%) BIA yielded significantly (p<0.001) lower %BF than ADP (28.3±7.4%) and WB BIA (28.9±5.0%). In men, UB (15.6±5.3%) and LB BIA (15.0±4.0%) also yielded significantly lower %BF values than ADP (17.6±7.7%; p=0.012 vs. UB BIA; p=0.008 vs. LB BIA) and WB BIA (19.1±6.7%; p<0.001 vs. UB and LB BIA). The differences in %BF between devices were greater in women compared to men: WB - UB BIA difference 5.0±2.6 vs. 3.6±3.3%, p=0.021 (women vs. men); WB - LB BIA difference 8.5±4.1 vs. 4.2±5.1%, p<0.001; ADP - UB BIA difference 4.5±5.9 vs 2.0±5.0%, p=0.028; ADP - LB BIA difference 7.9±6.3 vs. 2.7±6.2%, p<0.001; UB -LB BIA difference 3.4±3.5 vs. 0.7±3.2%, p<0.001. CONCLUSIONS: These results suggest that commercially available UB and LB BIA devices systematically underestimate %BF in both men and women compared to a validated multifrequency WB BIA and ADP. The degree of underestimation in %BF for commercially available BIA devices is greater in women compared to men. Use of these commercially available BIA devices may cause misclassification of body composition status, especially in women.