## 3 Results  
The advanced Taekwondo athlete group trained significantly more hours per week (12.3 \(\pm\) 3.6) compared to the novice group (5.3 \(\pm\) 0.8, \(p<\) 0.001; 95% CI: 4.58 to 15.27). Additionally, significant differences were noted in favor of the advanced group for the variable years of practice, with novice athletes showing 2.2 \(\pm\) 0.3 years compared to 8.1 \(\pm\) 2.9 years in advanced athletes (\(p<\) 0.001; 95% CI: 1.89 to 10.57). However, no significant differences were found between groups in mean peak EMG or body composition metrics. Table 1 provides descriptive statistics of the mean peak EMG across 15 roundhouse (_bandal chagui_) kicks for each muscle analyzed and body composition metrics for novice and advanced athletes. The results of independent samples t-tests for EMG data and body composition metrics are also presented. An independent samples t-test revealed significant mean differences in muscle co-contraction for specific muscle pairs between novice and advanced Taekwondo athletes (Figure 2). The advanced group demonstrated greater co-contraction across the different muscle pairs studied. The BF-RF pair showed a mean co-contraction index of 0.046 \(\pm\) 0.011 for the advanced group and 0.037 \(\pm\) 0.010 for the novice group, with a t = 3.660, \(p=0.001\) (95% CI for advanced: 0.042 to 0.050; for novices: 0.034 to 0.039), and \(d=0.907\) (large effect). \begin{table}
\begin{tabular}{c c c c c c c c} \hline \multirow{2}{*}{**Variable**} & \multicolumn{5}{c}{**Experience Level**} \\  & & **Novice Mean \(\pm\) SD** & **Advanced Mean \(\pm\) SD** & **95\% CI Lower** & **95\% CI Upper** & **t** & \(p\)**-Value** \\ \hline \multirow{8}{*}{Mean peak EMG from 15 kicks} & BF (\%) & 71.28 \(\pm\) 21.59 & 85.80 \(\pm\) 28.11 & \(-\)36.25 & 7.22 & \(-\)1.309 & 0.217 \\  & ST (\%) & 75.06 \(\pm\) 21.52 & 77.74 \(\pm\) 13.26 & \(-\)15.87 & 10.51 & \(-\)0.399 & 0.697 \\  & RF (\%) & 79.61 \(\pm\) 29.41 & 63.61 \(\pm\) 14.55 & \(-\)7.69 & 39.68 & 1.324 & 0.225 \\  & VM (\%) & 88.95 \(\pm\) 17.01 & 74.29 \(\pm\) 14.15 & \(-\)13.74 & 43.06 & 1.012 & 0.341 \\  & VL (\%) & 80.60 \(\pm\) 23.26 & 90.93 \(\pm\) 28.66 & \(-\)40.42 & 19.75 & \(-\)0.673 & 0.513 \\  & LG (\%) & 82.92 \(\pm\) 23.43 & 77.60 \(\pm\) 18.60 & \(-\)20.47 & 31.11 & 0.404 & 0.692 \\  & SO (\%) & 101.83 \(\pm\) 35.24 & 102.59 \(\pm\) 30.67 & \(-\)32.00 & 29.57 & \(-\)0.077 & 0.939 \\  & TA (\%) & 724.02 \(\pm\) 25.05 & 70.58 \(\pm\) 22.77 & \(-\)12.43 & 16.07 & 0.250 & 0.806 \\ \hline \multirow{8}{*}{Body composition} & Weight (kg) & 65.76 \(\pm\) 168.31 & 68.53 \(\pm\) 168.84 & \(-\)13.48 & 7.96 & \(-\)0.505 & 0.623 \\  & Height (m) & 23.24 \(\pm\) 26.58 & 23.84 \(\pm\) 29.75 & \(-\)10.28 & 9.23 & \(-\)0.105 & 0.918 \\ \cline{1-1}  & BMI (kg/m\({}^{2}\)) & 44.82 \(\pm\) 8.36 & 42.98 \(\pm\) 13.02 & \(-\)3.00 & 1.80 & \(-\)0.489 & 0.633 \\ \cline{1-1}  & Adipose mass (\%) & 11.15 \(\pm\) 2.30 & 8.59 \(\pm\) 2.60 & \(-\)9.02 & 2.68 & \(-\)1.063 & 0.307 \\ \cline{1-1}  & Muscle mass (\%) & 51.2 \(\pm\) 4.16 & 6.71 \(\pm\) 5.71 & \(-\)3.06 & 6.73 & 0.735 & 0.476 \\ \hline \end{tabular} BF: biceps femoris; BMI: body mass index; ST: semitendous; RF: rectus femoris; LG: lateral gastrocnemius; SO: soleus; TA: tibialis anterior; VL: vastas lateralis; VM: vastas medialis.  
\end{table} 
Table 1: Independent samples t-tests between novice and advanced athletes. The VM-BF pair also showed a significant difference, with mean values of 0.042 \(\pm\) 0.010 for the advanced group, 0.035 \(\pm\) 0.009 for the novice group, t = 2.744, \(p\) = 0.012 (95% CI for advanced: 0.026 to 0.033; for novices: 0.025 to 0.030), and \(d\) = 0.727 (medium effect). The SO-TA pair exhibited a significant difference as well, with mean values of 0.037 \(\pm\) 0.012 for the advanced group, 0.028 \(\pm\) 0.010 for the novice group, t = 2.407, \(p\) = 0.025 (95% CI for advanced: 0.039 to 0.046; for novices: 0.033-0.038), and \(d\) = 0.813 (large effect).