## 4 Discussion
\begin{table}
\begin{tabular}{c c c c c c c c} \hline \hline
**\%** & **Type** & **Triceps brachii** & **Mean** & **SD** & **SE** & **CI** & **CI** & **ANOVA** \\
**1 RM** & **of Load** & **Muscle** & **[\%MVIC]** & **SD** & **SE** & **-95\%** & **+95\%** & **F/p/ES** \\ \hline \multirow{4}{*}{70\%} & Pneumatic & Left Side (AD-LS) & 73.20 & 4.87 & 1.54 & 69.72 & 76.68 & \multirow{4}{*}{F = 0.64} \\ \cline{2-7}  & Pneumatic & Right Side (AD-PS) & 79.20 & 4.87 & 1.54 & 75.72 & 82.68 & \\ \cline{2-7}  & Barbells & Left Side (AD-LS) & 69.20 & 5.63 & 1.78 & 65.17 & 73.23 & \\ \cline{2-7}  & Barbells & Right Side (AD-PS) & 72.60 & 5.08 & 1.61 & 68.96 & 76.24 & \\ \hline \multirow{4}{*}{85\%} & Pneumatic & Left Side (AD-LS) & 83.90 * * & 4.09 & 1.29 & 80.97 & 86.83 & \\ \cline{2-7}  & Pneumatic & Right Side (AD-PS) & 89.90 * * * & 4.09 & 1.29 & 86.97 & 92.83 & \\ \cline{2-7}  & Barbells & Left Side (AD-LS) & 79.10 * & 3.14 & 0.99 & 76.85 & 81.35 & \\ \cline{2-7}  & Barbells & Right Side (AD-PS) & 76.40 * & 5.58 & 1.77 & 72.41 & 80.39 & \\ \hline \multirow{4}{*}{100\%} & Pneumatic & Left Side (AD-LS) & 102.50 & 5.38 & 1.70 & 98.65 & 106.35 & \\ \cline{2-7}  & Pneumatic & Right Side (AD-PS) & 105.70 & 4.99 & 1.58 & 102.13 & 109.27 & \\ \cline{2-7}  & Barbells & Left Side (AD-LS) & 91.50 & 2.72 & 0.86 & 89.56 & 93.44 & \\ \cline{2-7}  & Barbells & Right Side (AD-PS) & 97.50 & 5.99 & 1.89 & 93.22 & 101.78 & \\ \hline \hline \end{tabular}  
* \(p\leq 0.05\); \(p\leq 0.01\);
* \(p\leq 0.001\);
* \(p\leq 0.001\).  
\end{table} 
Table 3: Descriptive statistics for e side of Triceps brachii and type of load (free and pneumatic loading) N = 10.  
for 85% IRM between pneumatic loading, for which the activity was significantly lower than that recorded for free weights. Also, significantly greater activity for the AD-LS was observed for free weights compared to the same muscle group during pneumatic loading. Statistically significant differences in muscular activity of the TB between pneumatic loading and free weights were observed only for 85% 1 RM. For 85% 1 RM loading significant differences occurred between TB-LS and TB-RS between pneumatic loading and free weights in which the activity of TB-RS was significantly higher than TB-LS. The activity of the TB with the pneumatic loading was significantly higher, compared to the activity of TB performed with free weights. The TB is mainly composed of type II muscle fibers, which are utilized to a greater extent during tasks of higher force production, which may explain the significantly greater peak amplitude of the TB with pneumatic loading compared to a standard bar. The results for the pectoralis major showed no significant differences in muscle activity between pneumatic loading and free weights, for neither of the three applied loads. Our results indicate that during the two different exercise conditions (free weights and pneumatic loading) there is a different activation pattern, which means that particular prime movers are recruited in a different sequence and activated to a greater or lower extent. The observed variations in EMG activity between the two distinct conditions of executing the flat bench press likely stem from tonic muscle control mechanisms. When performing a motor task, the central nervous system (CNS) orchestrates the activation of specific muscle groups in a predetermined sequence. However, the activation of primary movers during a particular exercise may not remain constant when external loads change [17]. [PERSON] [18] proposes alternative principles of muscular activation, with the first principle emphasizing minimal energy expenditure. The second principle is founded on the anticipation of external forces, such as gravity, while the third principle involves muscle synergy across specific body segments. The recruitment of motor units and their firing frequency are governed by the central command of the CNS and may be modulated by reciprocal feedback mechanisms [19].