# Power Up: Comparing PAPE Responses in Free-Weight vs. Flywheel Resistance Training Systems
## 4 Discussion  
The aim of this study was to analyze the PAPE effect of a resistance training bout using free-weight and flywheel devices, where the intensity was matched through MPV on vertical jump performance and linear sprinting. Our initial hypothesis is partially supported, as both experimental groups responded similarly in the vertical jump and linear sprint tests. However, despite following the guidelines recommended in the literature, no PAPE effect was observed, as both groups experienced a reduction in performance in the physical tests. PAPE is a physiological phenomenon that leads to an acute improvement in muscular performance following a resistance training protocol [1; 2; 3; 5; 6]. PAPE is thought to result from an enhanced sensitivity of contractile proteins to calcium released from the sarcoplasmic reticulum, triggering a cascade of events that lead to a stronger muscular response [7; 8]. Recent studies suggest a positive PAPE effect after resistance training exercise with free-weight and flywheel devices [1; 6; 12; 15; 16]. Regarding flywheel training systems, the literature shows positive PAPE effects after a squat training session on vertical jump performance, with increases of up to 9% [15; 26]. On the other hand, the effects of strength training with traditional methods have already been widely studied in the literature [9]. Because studies showing the effects of strength training with flywheel systems are scarcer due to the recent emergence of these training systems, there is still uncertainty regarding which of these two methods produces more effective PAPE when similar training stimuli are \begin{table}
\begin{tabular}{c c c c c c c c} \hline \hline \multirow{2}{*}{**Variable**} & \multicolumn{3}{c}{**Flywheel**} & \multicolumn{3}{c}{**Free Weight**} & \multicolumn{2}{c}{**Time Effect**} \\  & **Pre** & **Post** & **ES** & **Pre** & **Post** & **ES** & \(p\)**-Value** \\ \hline
**CMJ (cm)** & 36.0 \(\pm\) 5.6 & 33.9 \(\pm\) 5.6 & \(-\)0.36 & 36.5 \(\pm\) 6.5 & 34.2 \(\pm\) 5.2 & \(-\)0.41 & \(<\)0.001 \\
**T10 (s)** & 1.80 \(\pm\) 0.08 & 1.82 \(\pm\) 0.08 & 0.14 & 1.81 \(\pm\) 0.09 & 1.83 \(\pm\) 0.09 & 0.16 & 0.083 \\
**Peak force (BW, \(\mathrm{N}\cdot\mathrm{kg}^{-1}\))** & 2.54 \(\pm\) 0.25 & 2.51 \(\pm\) 0.20 & \(-\)0.15 & 2.59 \(\pm\) 0.24 & 2.47 \(\pm\) 0.23 & \(-\)0.52 & \(<\)0.001 \\ \hline \hline \end{tabular} Data is presented as mean \(\pm\) SD. ES: effect size.  
\end{table} 
Table 2: Descriptive results of the physical tests conducted in the study. Figure 2: Acute changes in physical test post-intervention. T10: 10 m sprint time; CMJ: counter-movement jump; peak force: maximal force in BW value during CMJ. *: significant effect in post- vs. pre-test; \(\dagger\) significant time \(\times\) group interaction. used. Our results show that when performing three sets of six repetitions of the half-squat exercise at a similar intensity, regardless of whether the training is performed with flywheel or free-weight devices, CMJ performance will be impaired 4 min after exercise. To the best of our knowledge, this is the only study that does not show positive PAPE outcomes after a resistance training bout when comparing free-weight and flywheel devices. One possible explanation for the absence of a PAPE effect could be the choice of a 4 min post-exercise measurement, as previous research indicates that PAPE effects may peak between 3 and 10 min. Measuring only at 4 min may have missed the peak effects that occur closer to the 9-10 min range. A study by [PERSON] et al. [16] showed no changes 3 min after performing a resistance training session with low, moderate, and high loads using either free-weight or flywheel devices. Two studies showed PAPE 3 min after training with both types of devices, without a difference between them when training intensity was matched through peak power [1,6]. Similarly, two other studies showed increases in CMJ performance only in the flywheel group when training intensity was matched through peak power 3 min post-exercise [12,20].