# Relationship between Body Composition and Gross Motor Coordination in Six-Year-Old Boys and Girls
## 3 Results  
With respect to the whole sample of the study, 75% (n = 72) of the participants could be classified as normal weight and 20% (n = 19) as underweight. Only 5% (n = 5) could be classified as overweight, and there were no obese participants. Sample descriptive statistics for the tested variables are presented in Table 1.  
Significant sex differences were noted in six morphological variables; boys were significantly taller (by 0.34 \(\pm\) 0.01 m, \(p\) = 0.01), with greater muscle mass (by 1.08 \(\pm\) 0.42 kg, \(p\) = 0.01), protein mass (by 0.24 \(\pm\) 0.12 kg, \(p\) = 0.01), total body water (by 1.10 \(\pm\) 0.42 kg, \(p\) = 0.04), and extracellular water mass (by 0.42 \(\pm\) 0.17 kg, \(p\) = 0.02) compared to girls. Inversely, mineral mass was greater in girls than in boys (by 0.14 \(\pm\) 0.05 kg, \(p\) = 0.01). On the other hand, no significant gender differences were observed in the OCB test (\(p=0.46\)) (Table 2). \begin{table}
\begin{tabular}{c c} \hline
**Variables** & **Mean \(\pm\) SD** \\ \hline Age (years) & 6.22 \(\pm\) 0.43 \\ Obstacle course backwards (s) & 184.02 \(\pm\) 46.06 \\ Skeletal muscle mass (kg) & 11.50 \(\pm\) 2.08 \\ Body fat mass (kg) & 5.43 \(\pm\) 4.02 \\ Total water (kg) & 16.92 \(\pm\) 2.61 \\ Intracellular water mass (kg) & 9.89 \(\pm\) 1.34 \\ Extracellular water mass (kg) & 6.13 \(\pm\) 0.84 \\ Protein mass (kg) & 4.26 \(\pm\) 0.60 \\ Mineral mass (kg) & 1.61 \(\pm\) 0.25 \\ Fat-free mass (kg) & 22.46 \(\pm\) 2.74 \\ Body height (m) & 1.22 \(\pm\) 4.85 \\ Body weight (kg) & 24.67 \(\pm\) 3.11 \\ Body mass index (kg/m\({}^{2}\)) & 20.22 \(\pm\) 2.34 \\ \hline \end{tabular}
\end{table} 
Table 1: Descriptive statistics of variables. \begin{table}
\begin{tabular}{c c c c c} \hline
**Variables** & **Boysn = 42** & **Girlsn = 40** & **t** & **p** \\ \hline Obstacle course backwards (s) & 187.21 \(\pm\) 50.13 & 180.25 \(\pm\) 40.99 & 0.74 & 0.46 \\ Skeletal muscle mass (kg) & 11.99 \(\pm\) 2.01 & 10.92 \(\pm\) 2.03 & 2.60 & 0.01 \\ Body fat mass (kg) & 5.92 \(\pm\) 4.67 & 4.86 \(\pm\) 3.05 & 1.29 & 0.20 \\ Total water (kg) & 17.42 \(\pm\) 2.51 & 16.32 \(\pm\) 2.63 & 2.10 & 0.04 \\ Intracellular water mass (kg) & 10.13 \(\pm\) 1.39 & 9.61 \(\pm\) 1.23 & 1.93 & 0.06 \\ Extracellular water mass (kg) & 6.32 \(\pm\) 0.87 & 5.90 \(\pm\) 0.76 & 2.49 & 0.02 \\ Protein mass (kg) & 4.37 \(\pm\) 0.60 & 4.13 \(\pm\) 0.57 & 2.01 & 0.05 \\ Mineral mass (kg) & 1.54 \(\pm\) 0.22 & 1.69 \(\pm\) 0.25 & \(-\)2.98 & 0.01 \\ Fat-free mass (kg) & 22.37 \(\pm\) 3.04 & 22.57 \(\pm\) 2.34 & \(-\)0.36 & 0.72 \\ Body height (m) & 1.24 \(\pm\) 0.39 & 1.20 \(\pm\) 0.52 & 3.73 & 0.01 \\ Body weight (kg) & 24.61 \(\pm\) 2.63 & 24.79 \(\pm\) 3.63 & \(-\)0.35 & 0.72 \\ Body mass index (kg/m\({}^{2}\)) & 19.89 \(\pm\) 2.05 & 20.62 \(\pm\) 2.60 & \(-\)1.50 & 0.14 \\ \hline \end{tabular}
\end{table} 
Table 2: Sex differences in morphological variables and coordination. Morphological variables showed trivial-to-weak (r = 0.01-0.15) associations with the OCB scores, without reaching statistical significance (\(p\leq 0.16\)). Particularly, body weight and protein mass showed a small correlation (r = 0.13-0.15, \(p\geq 0.16\)) with the OCB test. Additionally, a small correlation (r = 0.10-0.11, \(p\geq 0.22\)) was observed between the OCB test and the intracellular and extracellular water mass, but only in girls. All other morphological variables showed a trivial (r = 0.01-0.05, \(p\geq 0.38\)) association with the OCB test. Accordingly, a system of predictor variables did not have a statistically significant effect on the criterion variable (i.e., OCB) in boys and girls (F = 0.43, R\({}^{2}\) = 0.09, \(p\) = 0.91 and F = 0.42, R\({}^{2}\) = 0.12, \(p\) = 0.92, respectively). The multiple correlation coefficient in boys was R = 0.29 and R = 0.34 in girls. The percentage of shared variability between the system of predictor variables and the examined criterion was slightly higher in girls (12%) than in boys (9%).