## 3 Results
### Postural Control Indices before and after Effort (Eyes Closed)  
After the effort, significant increases were registered in EA (medium ES), AP\({}_{\rm R}\), and ML\({}_{\rm R}\) (in both cases, large ES), with a relatively greater increase in the AP\({}_{\rm R}\), as well as decrease in MF (medium ES). MV did not change significantly (small ES) (Table 4).  
\begin{table}
\begin{tabular}{c c c c c} \hline \hline  & **Before** & **After** & **Difference (\%)** & \(p\)**-Value** & **ES** \\ \hline EA [mm\({}^{2}\)] & 90.8 (42.9-291.3) & 265 (158–761) & 181.7 (\(-\)12.5–657.5) & 0.001 * & 0.49 \\  & \multicolumn{1}{c}{} & \multicolumn{1}{c}{} & \multicolumn{1}{c}{} & \\  & \multicolumn{1}{c}{} & \multicolumn{1}{c}{} & \multicolumn{1}{c}{} & \\  & \multicolumn{1}{c}{} & \multicolumn{1}{c}{} & \multicolumn{1}{c}{} & \\  & \multicolumn{1}{c}{} & \multicolumn{1}{c}{} & \multicolumn{1}{c}{} & \\  & \multicolumn{1}{c}{} & \multicolumn{1}{c}{} & \multicolumn{1}{c}{} & \\ \end{tabular}
\end{table}
Table 4: Postural control indices before and after the effort (eyes closed).  
\begin{table}
\begin{tabular}{c c c c} \hline \hline  & **Median (Q1-Q3)** & **Minimum** & **Maximum** & **CQV (\%)** \\ \hline Peak power [W] & 910 (851–983) & 710 & 1232 & 7.3 \\ Peak power [W \(\times\) kg\({}^{-1}\)] & 14.2 (13.4–15.6) & 13.4 & 15.6 & 7.7 \\ Time to peak power [s] & 3.30 (2.50–3.80) & 1.00 & 7.40 & 19.7 \\ Mean power [W] & 716 (671–774) & 553 & 894 & 7.1 \\ Mean power [W \(\times\) kg\({}^{-1}\)] & 11.4 (10.6–11.5) & 10.3 & 12.6 & 4.1 \\ Minimal power [W] & 535 (466–579) & 419 & 658 & 10.8 \\ Minimal power [W \(\times\) kg\({}^{-1}\)] & 8.2 (7.8–8.8) & 6.3 & 8.8 & 6.0 \\ Fatigue index [\%] & 41.2 (37.6–46.8) & 31.0 & 56.0 & 10.9 \\ Blood lactate 3\({}^{\prime}\) [mmol \(\times\) L\({}^{-1}\)] & 12.9 (12.0–14.0) & 9.8 & 16.0 & 7.7 \\ Blood lactate 6\({}^{\prime}\) [mmol \(\times\) L\({}^{-1}\)] & 11.9 (10.6–13.3) & 8.6 & 15.1 & 11.3 \\ \hline \hline \end{tabular} \(\overline{\text{Q}_{1}}\)-\(\overline{\text{Q}_{2}}\)-\(\overline{\text{Q}_{3}}\)=1 st and 3 rd quartiles; CQV—coefficient of quartile variation.  
\end{table}
Table 2: Kinetic data collected during the effort and BL concentration after its completion.  
\begin{table}
\begin{tabular}{c c c c c} \hline \hline  & **Before** & **After** & **Difference (\%)** & \(p\)**-Value** & **ES** \\ \hline EA [mm\({}^{2}\)] & 92.2 (56.6–125.6) & 250 (151–670) & 231.2 (79.2–564.1) & 0.000 * & 0.59 \\  & CQV: 37.8\% & CQV: 63.2\% & & \\ AP\({}_{\rm R}\) [mm] & 12.0 (10.6–16.1) & 25.7 (18.7–45.3) & & \\  & CQV: 20.6\% & CQV: 41.6\% & & \\ ML\({}_{\rm R}\) [mm] & 10.8 (8.6–14.3) & 17.8 (10.9–25.6) & & \\  & CQV: 24.9\% & CQV: 40.1\% & & \\ AP\({}_{\rm R}\)/ML\({}_{\rm R}\) & 1.07 (0.8–1.57) & 1.4 (12.1–1.96) & & \\ AP\({}_{\rm R}\)/ML\({}_{\rm R}\) & CQV: 31.4\% & CQV: 27.3\% & 12.3 (–11.7–114.5) & 0.136 & 0.10 \\ MV [mm \(\times\) s\({}^{-1}\)] & 10.7 (9.1–12.3) & 10.6 (10.1–11.7) & & \\  & CQV: 15.0\% & CQV: 7.3\% & & \\  & 1.11 (0.95–12.6) & 0.80 (07.2–0.87) & & \\  & CQV: 14.0\% & CQV: 9.4\% & & \\ \hline \hline \end{tabular} Data are expressed as median (with 1 st and 3 rd quartiles); EA—95%-confidence ellipse area; AP\({}_{\rm R}\), ML\({}_{\rm R}\)—CoP range displacement in the AP and ML planes; AP\({}_{\rm R}\)/ML\({}_{\rm R}\)—ratio of AP\({}_{\rm R}\) and ML\({}_{\rm B}\); MV—CoP mean velocity; MF—CoP mean frequency; \(p\)-value—probability of Type I error; * statistically significant difference; ES—effect size; CQV—coefficient of quartile variation.  
\end{table}
Table 3: Postural control indices before and after the effort (eyes open).