Development and Validation of an Anthropometric Equation to Predict Fat Mass Percentage in Professional and Semi-Professional Male Futsal Players

Abstract

This study aimed to (i) characterise the body composition of professional and semi-professional male futsal players, (ii) assess the validity of commonly used equations to estimate FM%, (iii) develop and cross-validate a futsal-specific FM% prediction equation. In a cross-sectional design, 78 adult male futsal players were assessed for body mass, stature, skinfolds, and girths as per the International Society for the Advancement of Kinanthropometry protocol and completed a dual-energy X-ray absorptiometry (DXA) scan for reference body composition data. Using paired-sample t-tests, the FM% from the DXA and nine published equations were compared. New sport-specific models were developed by stepwise multiple regression. Existing equations were cross-validated using the least squares regression, concordance correlation coefficient, and the Bland–Altman analyses. New equations were further cross-validated using the PRESS approach. None of the existing equations accurately predicted the DXA-derived FM% (p < 0.001; R2 ≤ 0.76, SEE ≥ 1.59; CCC ≤ 0.83; bias = −8.2% to −1.3%, limited agreement, and varying trends). The novel Bettery® equation: −0.620 + (0.159 ∗ Σ4SKF [triceps, abdominal, iliac crest, and front thigh (mm)]) + (0.120 ∗ waist girth (cm)), demonstrated a high accuracy (R2 = 0.85, SEE = 1.32%), a moderate strength of agreement (CCC = 0.92), no bias (0.2%), good agreement (±2.5%), and no trend (r = −0.157; p = 0.170) against the DXA. The Bettery® equation is the first to allow for a valid and sport-specific assessment of FM% in male futsal players.

Body Composition, Nutritional Intake Assessment, and Perceptions about Diet for Health and Performance: An Exploratory Study for Senior Futsal Players

“…As for basic anthropometric measurements, the senior futsal players showed a mean height of 1.74 ± 0.07 m and a mean weight of 75.2 ± 12 kg. These results were similar to the means found in other studies with Portuguese futsal players: 1.75 ± 0.07 m and 71.5 ± 7.6 kg [ 29 ], and 1.76 ± 0.08 m and 72.8 ± 1.0 kg [ 19 ].…”

“…This study also shows that players are globally eutrophic (BMI 24.7 ± 3.5 kg/m 2 ) and have an average FM of 19.1 ± 4.0%, which may be considered slightly higher, but within range, when compared with other professional and semi-professional Portuguese futsal players, who present an average FM of 15.8 ± 3.2% [ 19 ]. In fact, in futsal practice, lower FM tends to favour maximum player performance, as this sport demands high-intensity and intermittent actions that require high physical effort from the players [ 1 ].…”

“…The percentage of fat mass (FM) was calculated according to the improved equation developed by Giro et al [ 19 ] for futsal players and the resulting subject health status was classified according to Gallagher et al’s method [ 20 ]. The Body Mass Index (BMI) was calculated using the Quetelet index: body mass/height 2 (kg/m 2 ), according to the WHO classification [ 21 ].…”

Methods over Materials: The Need for Sport-Specific Equations to Accurately Predict Fat Mass Using Bioimpedance Analysis or Anthropometry

“…When more than two predictive equations were identified for each group (generalized, athletic, and sport-specific) and method (BIA and anthropometry), only two of them were randomly selected using the random.org website. A total of four generalized [ 21 , 22 , 23 , 24 ], four athletic [ 25 , 26 , 27 , 28 ], and two sport-specific predictive equations [ 29 , 30 ] were selected and are reported in Table 1 .…”

“…9 = Matias et al [ 29 ]; Eq. 10 = Giro et al [ 30 ]. The dotted line identifies the mean value obtained with DXA; * = significant difference from DXA.…”