## 3 Results  
Table 1 presents the muscle activation levels for the six exercises at two intensities. There were no differences between left and right side of muscles during the symmetrical exercises and no difference between ipsilateral and contralateral when the exercises CL and CR were performed to right versus left side. Therefore, the data were averaged over left and right muscles or ipsilateral and contralateral muscles, except during CL for mUNE and mSCM. This is due to the higher muscle activity during CL in ipsilateral than contralateral for mUNE (30.2% \(\pm\) 13.6% vs. 12.8% \(\pm\) 6.8%, \(p<0.001\), for 20 RM, and 45.5% \(\pm\) 14.6% vs. 17.2% \(\pm\) 7.1%, \(p<0.001\), for 12 RM) and for mSCM (25.6% \(\pm\) 7.7% vs. 11.6% \(\pm\) 6.3%, \(p=0.001\), for 20 RM, and 41.5% \(\pm\) 14.6% vs. 15.3% \(\pm\) 8.4%, \(p=0.001\), for 12 RM). Therefore, for CL the higher value of %MVE in ipsilateral of mUNE and mSCM were used as the results (Table 1). The repeated measures ANOVAs revealed significantly different muscle activation between the types of exercise for: mUTR (F(1.099, 10.987) = 97.622, \(p<0.001\)), mUNE (F(2.359, 23.59) = 29.038, \(p<0.001\)), and mSCM (F(5, 50) = 18.045, \(p<0.001\)), respectively. Figure 2 presents the contrast of muscle activity during the exercise, which induced the highest activation with other exercises. For mUTR, SH induced highest activity, and this was significantly higher than all of the remaining exercises, except RF. For mUNE, CE induced the highest activity and this was higher than during CF, CL and CR, but not significantly different from SH, and RF. For mSCM, CF induced the highest activity and this was higher than in all the remaining exercises. Furthermore, when compared with 20 RM, the mean muscle activity of all exercises was significantly higher (relative increase 34%) during 12 RM. For the \begin{table}
\begin{tabular}{c c c c c c c c} \hline \hline \multirow{2}{*}{**Muscle**} & \multirow{2}{*}{**Intensity**} & \multicolumn{6}{c}{**Exercise**} \\ \cline{3-8}  & & **SH** & **RF** & **CE** & **CF** & **CL** & **CR** \\ \hline mUTR & 20 RM & **78.8 \(\pm\) 24.0** & **75.9 \(\pm\) 30.7** & 3.4 \(\pm\) 1.8 & 1.9 \(\pm\) 1.3 & 8.1 \(\pm\) 4.6 & 3.7 \(\pm\) 2.3 \\  & 12 RM & **100.3 \(\pm\) 29.8** & **91.6 \(\pm\) 32.8** & 4.8 \(\pm\) 2.5 & 2.4 \(\pm\) 2.0 & 9.1 \(\pm\) 4.1 & 4.3 \(\pm\) 2.8 \\ \hline mUNE & 20 RM & 45.7 \(\pm\) 16.7 & 39.1 \(\pm\) 22.3 & 50.9 \(\pm\) 25.8 & 7.6 \(\pm\) 3.2 & 30.2 \(\pm\) 13.6 & 10.4 \(\pm\) 4.6 \\  & 12 RM & **61.9 \(\pm\) 16.8** & 55.4 \(\pm\) 16.3 & **67.6 \(\pm\) 29.8** & 8.5 \(\pm\) 3.8 & 45.5 \(\pm\) 14.6 & 12.0 \(\pm\) 4.7 \\ \hline mSCM & 20 RM & 16.7 \(\pm\) 13.5 & 14.2 \(\pm\) 8.9 & 15.1 \(\pm\) 11.3 & 44.8 \(\pm\) 16.6 & 25.6 \(\pm\) 7.7 & 28.8 \(\pm\) 9.9 \\  & 12 RM & 26.2 \(\pm\) 16.5 & 22.9 \(\pm\) 14.8 & 10.1 \(\pm\) 6.3 & 51.7 \(\pm\) 16.4 & 41.5 \(\pm\) 14.6 & 42.5 \(\pm\) 11.6 \\ \hline \hline \end{tabular}
\end{table} 
Table 1: Mean muscle activity (%MVE) for representative muscle groups shown for each exercise at 12 RM and 20 RM intensities. Values are presented as mean \(\pm\) SD. Values \(>\) 60% MVE are marked in bold. Italic values are unilateral data, see text. specific muscle groups the relative increase were 26% in mUTR (\(p<0.001\)), 41% in mUNE (\(p<0.001\)), and 35% in mSCM (\(p<0.001\)). (Figure 3). Figure 3: Mean muscle activity (%MVE) for all exercises in the upper trapezius muscle (mUTR), upper neck extensors muscles (mUNE), and sternocleidomastoideus muscles mSCM during intensities of 12 RM and 20 RM. * indicates significant difference between training intensities. Figure 2: The muscle activity of the upper trapezius muscle (mUTR), upper neck extensors muscles (mUNE) and sternocleidomastoideus muscles (mSCM) were compared in six different types of exercises. The highest muscle activation (%MVE) was found during SH for mUTR, during CE for mUNE and during CF for mSCM. * marks exercises with significantly lower activation than the exercise inducing the highest muscle activation.