## 4 Discussion
\begin{table}
\begin{tabular}{c c c c c c c} \hline \hline  & & **Pre-Test** & **Post-Test** & **SWC** & **Result** & \(p\) & **ES** \\ \hline VT1 & & & & & & & \\  & Stiffness (kn/m) & \(10.95\pm 1.61\) & \(10.73\pm 0.39\) & 0.322 & 0.225 & 0.751 & 0.17 \\  & CT (ms) & \(207.88\pm 1.37\) & \(204.98\pm 1.93\) & 0.273 & 2.9 & 0.069 & 1.39 \\  & VO (cm) & \(9.15\pm 0.52\) & \(9.03\pm 0.31\) & 0.104 & 0.125 & 0.492 & 0.39 \\  & Cadence (spm) & \(165.68\pm 3.31\) & \(167\pm 1.59\) & 0.663 & \(-1.325\) & 0.292 & 0.64 \\  & FT (s) & \(0.154\pm 0.01\) & \(0.154\pm 0.005\) & 0.001 & 0.000 & 0.975 & 0.02 \\  & SL norm (m) & \(1.62\pm 0.06\) & \(1.72\pm 0.09\) & 0.013 & \(-0.099\) & 0.056 & 1.52 \\  & Duty Factor & \(0.57\pm 0.01\) & \(0.57\pm 0.01\) & 0.002 & 0.003 & 0.257 & 0.7 \\ \hline VT2 & & & & & & & \\  & Stiffness (kn/m) & \(11.03\pm 1.32\) & \(10.55\pm 0.41\) & 0.264 & 0.475 & 0.488 & 0.39 \\  & CT (ms) & \(191.35\pm 2.94\) & \(194.73\pm 4.12\) & 0.587 & \(-3.375\) & 0.187 & 0.85 \\  & VO (cm) & \(8.75\pm 0.32\) & \(8.75\pm 0.17\) & 0.064 & 0.000 & 1 & 0 \\  & Cadence (spm) & \(172.2\pm 2.18\) & \(171.2\pm 1.85\) & 0.436 & 1.000 & 0.414 & 0.47 \\  & FT (s) & \(0.157\pm 0.005\) & \(0.156\pm 0.003\) & 0.0009 & 0.0014 & 0.377 & 0.52 \\  & SL norm (m) & \(1.79\pm 0.06\) & \(1.90\pm 0.08\) & 0.012 & \(-0.104\) & 0.017 * & 2.41 \\  & Duty Factor & \(0.06\pm 0.01\) & \(0.56\pm 0.01\) & 0.002 & \(-0.006\) & 0.169 & 0.9 \\ \hline MAS & & & & & & \\  & Stiffness (kn/m) & \(10.93\pm 1.58\) & \(10\pm 0.34\) & 0.317 & 0.925 & 0.287 & 0.65 \\  & CT (ms) & \(176.33\pm 4.5\) & \(181.13\pm 1.1\) & 0.899 & \(-4.800\) & 0.165 & 0.91 \\  & VO (cm) & \(7.93\pm 0.62\) & \(8.05\pm 0.31\) & 0.125 & \(-0.125\) & 0.633 & 0.27 \\  & Cadence (spm) & \(182.5\pm 5.38\) & \(179.9\pm 2.47\) & 1.076 & 2.600 & 0.363 & 0.54 \\  & FT (s) & \(0.153\pm 0.001\) & \(0.152\pm 0.001\) & 0.002 & 0.000 & 0.956 & 0.3 \\  & SL norm (m) & \(1.96\pm 0.05\) & \(1.99\pm 0.09\) & 0.010 & \(-0.029\) & 0.279 & 0.66 \\  & Duty Factor & \(0.54\pm 0.02\) & \(0.54\pm 0.01\) & 0.004 & \(-0.007\) & 0.406 & 0.48 \\ \hline \hline \end{tabular}  
* Significantly different from the pre-training value (\(p<0.05\)); VT = ventilatory threshold; MAS = maximal aerobic speed; CT = contact time; VO = vertical oscillation; FT = flying time; SL norm = step length normalized; SWC = smallest worthwhile change; ES = effect size.  
\end{table} 
Table 3: The pre-test and post-test biomechanical parameters for running after 29 weeks training. determined. For example, VT1 was improved from 66.33% VO\({}_{2}\)max (pre-test) to 73.56% VO\({}_{2}\)max (post-test) and VT2 was improved from 84.29% VO\({}_{2}\)max (pre-test) to 87.94% VO\({}_{2}\)max (post-test). From a practical point of view, it means that triathletes could run faster at the same physiological intensity [50]. These results are supported by [PERSON] and [PERSON] [51], who determined the intensity of VT1 as between 65 and 75% of the % VO\({}_{2}\)max and VT2 as between 75 and 85% of the % VO\({}_{2}\)max in trained athletes. Thirdly, focusing attention on the biomechanical parameters, large ESs also could explain the improvement in the performance. The largest ESs were found in SL normalized, increasing 10 cm in VT1 and 11 cm in VT2. These results are supported by previous research [52] in which the maximal and submaximal SL correlated with performance and seems to be fundamental to reach high speeds. The same authors show that the maximal SL recorded in half marathon runners is 1.70 m while in this study it is 1.99 m (in elite triathletes). Therefore, this big difference could explain that, in long-distance events, SL is negatively related to performance [18]. Besides, in previous research [18], it was shown to be worth it to analyze the \"duty factor\", which shows a negative relationship with speed, suggesting that future work should be applied in higher level athletes, with the aim to accept or reject some of the results and conclusions.