## 3 Results  
According to the Shapiro-Wilk test, the data were normally distributed (\(p\) > 0.05). Thus, parametric analyses were followed for all examined variables. Each participant's BF% and the total distance covered during the 10 h swim were also recorded individually as shown in Table 1 (Appendix A). Fat percentages ranged from 19.6 to 35.0%, and distances covered ranged between 18,900 m and 33,600 m. However, no apparent association was observed between individual fat percentage and total distance swum. Statistically significant differences were observed in the Fb and BP after the 10 h swimming effort (Figures 1 and 2). Analysis of the swimmers' pacing strategy revealed a consistent pattern: a steady leg-kick rhythm and a 2:1 arm-stroke to breath ratio, occasionally shifting to 3:1. Stroke frequency remained consistent at approximately 30 strokes per minute, reflecting a low-intensity and controlled swimming pace. Also, each swimmer followed their personal nutritional preferences; however, across all participants, high-glycemic-index foods rich in carbohydrates, with moderate protein and low-fat content, were preferred. None of the athletes took excessively long breaks, and all maintained a steady routine of swimming and rest. \begin{table}
\begin{tabular}{c c c c} \hline \hline
**Liquids** & **Food** & **Supplements** & **Drugs** \\ \hline  & Banana & & \\  & Chocolate & & \\   Refreshment drinks & Tahini & & Anti-inflammatory pills \\   Coffee & Sandwich & Powerbar & Caffe \\   Isotonics & Chicken & Carbons & Caffeine gel \\   Water & Biscuits & Fruit gels & Salt stick \\   Electrolytes & Croissant & & \\  & Pasta & & \\  & Bread & & \\ \hline \hline \end{tabular}
\end{table} 
Table 1: Food and supplement intake. Regarding the RPE (Ratings of Perceived Exertion), participants reported their effort levels in a consistent pattern. Specifically, during the first and second hours, RPE scores ranged between 7 and 9. Between the fourth and seventh hour, values increased by two to three points and then stabilized. In the final hours, RPE approached 20 (Figure 3). The actual swimming time out of the total 10 h was 509.1 min. An additional 59.1 min were spent in active recovery (AR) and 31.8 min in passive recovery(PR) (Figure 4). Figure 1: Skinfold thickness measurements at the triceps (Ft), biceps (Fb), suprailiac (Fh), and subscapular (Fs). Statistically significant difference (\(p=0.022\)) *. Figure 2: Blood pressure (BPs-BPb) before and after the 10 h swim. Statistically significant difference (\(p=0.030\)) *. Additionally, no significant correlation was observed between fat percentage and total swim distance (\(r=-0.215\), \(p=0.57\)), nor between BMI and distance covered (\(r=-0.095\), \(p=0.78\)). The strongest association with performance was found in post-swim Ph (\(r=-0.682\), \(p=0.043\)), accounting for approximately 47% of the variance in swim distance (\(R^{2}=0.465\)). This is visually represented in Figure 5. All statistical results are presented with two decimal precision and were verified for normality using the Shapiro-Wilk test. The full dataset is available in Appendix A. No statistically significant changes were observed in F, LBM, BMI, and HR (\(p>0.05\)) (Table 2). \begin{table}
\begin{tabular}{l c c c c c c} \hline \hline
**Parameters** & \begin{tabular}{c} **Meters** \\ **(m)** \\ \end{tabular}  & \begin{tabular}{c} **BF\%** \\ **(\%)** \\ \end{tabular}  & \begin{tabular}{c} **LBM** \\ **(kg)** \\ \end{tabular}  & \ \begin{tabular}{c} **BMI** \\ **(kg/m\({}^{2}\))** \\ \end{tabular}  & \begin{tabular}{c} **HR** \\ **(bpm)** \\ \end{tabular}  & \(p\)**-Value** \\ \hline
**Before** & \ \begin{tabular}{c} 24.2 \(\pm\) 6.8 \\ 25,993 \(\pm\) 4832 \\ \end{tabular}  &
\begin{tabular}{c} 61.8 \(\pm\) 11.8 \\ 25 \(\pm\) 5.9 \\ 25 \(\pm\) 5. BW remained relatively stable pre- and post-swim (82.3 \(\pm\) 12.4 vs. 82.0 \(\pm\) 12.6 kg, \(p\) > 0.05), suggesting that any minor fluctuations were likely due to transient fluid shifts rather than actual fat mass reduction.