## 3 Results  
The general characteristics of the study participants, such as age, height, waist circumference, body mass, and BMI, are depicted in Table 2. The values are given as the mean \(\pm\) SD, with the range of the values enclosed in brackets. A statistically significant difference was present between the %BF measured with the two body composition techniques (Table 3). BIA underestimated the %BF by 3.07 \(\pm\) 5.81% in comparison to the AP. A strong concordance was observed between the two methods according to the concordance correlation coefficient analysis (CCC = 0.82) (Figure 1). \begin{table}
\begin{tabular}{c c c c c} \hline  & **All (\(\pi\) = 80)** & **Female (\(\pi\) = 39)** & **Male (\(\pi\) = 41)** & \(\mathbf{p}\)**-Value** \\ \hline Age (yrs) & 36.31 \(\pm\) 11.73 & 38.36 \(\pm\) 12.74 & 34.97 \(\pm\) 11.63 & 0.15 \\  & (18–71) & (18–71) & (18–56) & 0.15 \\ Height (cm) & 170.38 \(\pm\) 10.3 & 162.38 \(\pm\) 7.61 & 180 \(\pm\) 5.71 & \textless{}0.001 \\  & (148–192) & (148–179.5) & (168–192) & \textless{}0.001 \\ Waist circumference (cm) & 82.65 \(\pm\) 14.2 & 76.46 \(\pm\) 13.88 & 88.54 \(\pm\) 11.94 & \textless{}0.001 \\  & (59–131) & (59–118) & (69.5–131) & \textless{}0.001 \\ Body mass (kg) & 73.571 \(\pm\) 18.457 & 62.501 \(\pm\) 15.267 & 84.102 \(\pm\) 14.771 & \textless{}0.001 \\  & (98.984–148.8) & (39.894–114.681) & (58.323–148.8) & \textless{}0.001 \\ BMI (kg/m\({}^{2}\)) & 25.23 \(\pm\) 5.59 & 23.84 \(\pm\) 6.16 & 26.55 \(\pm\) 4.7 & 0.03 \\  & (14.98–49.43) & (14.98–44.15) & (19.49–49.43) & & \\ \hline \end{tabular}
\end{table} 
Table 2: General characteristics of the subjects in the study group (mean \(\pm\) standard deviation, range of values). \begin{table}
\begin{tabular}{c c c c c} \hline  & **\%BF\({}_{\text{AP}}\) (\%)** & **\%BF\({}_{\text{BIA}}\) (\%)** & **\%BF\({}_{\text{AP}}\) – \%BF\({}_{\text{BIA}}\) (\%)** & \(\mathbf{p}\)**-Value** \\ \hline
**All (\(\pi\) = 80)** & 26.62 \(\pm\) 11.35 & 23.55 \(\pm\) 10.18 & 3.07 \(\pm\) 5.81 & \textless{}0.001 \\  & (7.5–52.55) & (8.36–53.03) & & \\ \hline
**Sex** & & & & \\ -male (\(\pi\) = 41) & 21.73 \(\pm\) 9.66 & 20.45 \(\pm\) 7.57 & 1.28 \(\pm\) 6.57 & 0.2 \\  & (7.5–46.7) & (11.36–45.74) & & \\ -female (\(\pi\) = 39) & 31.77 \(\pm\) 10.8 & 26.81 \(\pm\) 11.58 & 4.95 \(\pm\) 4.23 & \\  & (9.6–52.55) & (8.36–53.03.18) & & \\ \hline
**BMI (kg/m\({}^{2}\))** & & & & \\ \(<\)18.5 (\(\pi\) = 5) & 18.66 \(\pm\) 5.83 & 13.59 \(\pm\) 4.33 & 5.07 \(\pm\) 2.6 & 0.012 \\  & (9.6–25.05) & (8.36–18.13) & & \\
18.5–24.9 (\(\pi\) = 36) & 23.21 \(\pm\) 8.5 & 19.17 \(\pm\) 5.86 & 4.04 \(\pm\) 5.74 & \textless{}0.001 \\  & (7.5–39.2) & (9.83–31.41) & & \\
25–29.9 (\(\pi\) = 29) & 26.66 \(\pm\) 11.15 & 24.98 \(\pm\) 8.79 & 1.68 \(\pm\) 6.64 & 0.18 \\  & (8.65–46.6) & (11.58–41.7) & & \\ \(>\)30 (\(\pi\) = 10) & 42.79 \(\pm\) 8.74 & 40.16 \(\pm\) 9.08 & 2.63 \(\pm\) 4.02 & 0.07 \\  & (26.6–52.55) & (27.67–53.03) & & \\ \hline
**Central obesity \({}^{*}\)** & & & & \\ Absent (\(\pi\) = 52) & 22.21 \(\pm\) 8.67 & 19.25 \(\pm\) 6.67 & 2.97 \(\pm\) 6.21 & \textless{}0.001 \\  & (7.5–46.6) & (8.36–39.3) & & \\ Present (\(\pi\) = 28) & 34.81 \(\pm\) 11.32 & 31.54 \(\pm\) 10.84 & 3.26 \(\pm\) 5.1 & \textless{}0.001 \\  & (11.7–52.55) & (13.93–53.03) & & \\ \hline \end{tabular} \({}^{*}\) central obesity defined as WHHR \(>\) 0.5.  
\end{table} 
Table 3: Percentage body fat (%BF) measured by air-displacement plethysmography (AP) and bioelectrical impedance (BIA) for the entire sample (\(n\) = 80) and for the subjects divided in subgroups according to sex, body mass index (BMI), and the presence of central obesity defined according to the waist-to-height ratio (WHtR). Values are provided as mean \(\pm\) standard deviation, with range between brackets. BIA tends to underestimate the %BF in subjects of both sexes. However, the difference for the male subjects is smaller and without statistical significance in comparison to the difference for females (1.28 \(\pm\) 6.57% in men vs. 4.95 \(\pm\) 4.23% in women).