# How Should the Transition from Underwater to Surface Swimming Be Performed by Competitive Swimmers?
## 3 Results  
Table 1 shows the kinematic parameters of competitive swimmers during pre-transition and transition phases of the push start. In the pre-transition phase, there were no differences on the kicking parameters of the front crawl, backstroke and butterfly strokes. However, there was stroke effect on the body depth (F = 18.18, \(p\) = 0.000, ES = 0.31), trunk inclination 1 (F = 13.06, \(p\) = 0.000, ES = 0.24), trunk inclination 2 (F = 5.82, \(p\) = 0.001, ES = 0.13) and body inclination 1 (F = 12.71, \(p\) = 0.000, ES = 0.24). In the transition phase, differences were observed between strokes on the SL (F = 6.03, \(p\) = 0.001, ES = 0.13) and SR (F = 54.09, \(p\) = 0.000, ES = 0.57) values, as well as on the majority of segmental parameters: body depth (F = 39.47, \(p\) = 0.000), trunk inclination 2 (F = 17.97, \(p\) = 0.000, ES = 0.31), body inclination 1 (F = 51.77, \(p\) = 0.000, ES = 0.57) and body inclination 2 (F = 8.22, \(p\) = 0.000, ES = 0.17). Figure 2 shows relationships of the pre-transition and transition parameters with the average velocity of each phase. During pre-transition, average velocity was small to moderately correlated with body depth in front crawl (\(r\) = 0.262) and butterfly (\(r\) = 0.283) strokes, whereas no correlations (\(p\) > 0.05) were observed for the body inclination. For the kicking variables, kick rate and kick length (but not amplitude) were moderate to largely correlated with faster velocities in all strokes, except the backstroke kicking rate. During transition, body inclination and body depth were negatively correlated with velocity in backstroke whereas no relationships were observed for the remaining strokes. In this phase, some of the coordinative parameters were moderately related to transition velocity, indicating shorter time gaps related to faster velocities except for DRP2 in front crawl and DRP3 in breaststroke. \begin{table}
\begin{tabular}{c c c c c} \hline \hline  & **Front Crawl** & **Backstroke** & **Butterfly** & **Breaststroke** \\ \hline
**Pre-transition** & & & & \\ Kick length (m/cycle) & 0.77 (0.12) & 0.72 (0.10) & 0.77 (0.12) & 3.66 (0.50) \\ Kick rate (cycles/s) & 2.15 (0.31) & 2.14 (0.30) & 2.14 (0.35) & 0.39 (0.07) \\ Kick amplitude (m) & 0.29 (0.06) & 0.27 (0.18) & 0.31 (0.06) & - \\ Body depth (m) & \(-\)0.39 (0.13) & \(-\)0.62 (0.22) a & \(-\)0.36 (0.12) a & \(-\)0.53 (0.16) a \\ Trunk inclination 1 (°) & 16.20 (5.26) & 8.25 (6.13) a & 16.13 (5.35) a & 10.56 (7.30) a \\ Trunk inclination 2 (°) & 4.58 (3.07) & 9.01 (5.22) a & 4.91 (3.57) a & 7.42 (6.38) \\ Body inclination 1 (°) & 14.31 (5.07) & 6.17 (4.55) a & 13.14 (4.87) a & 9.25 (8.19) \\ Body inclination 2 (°) & 6.44 (3.96) & 4.42 (3.70) & 6.32 (4.50) & 6.63 (5.39) \\
**Transition** & & & & \\ Body depth (m) & \(-\)0.20 (0.11) & \(-\)0.52 (0.17) a & \(-\)0.20 (0.11) a & \(-\)0.34 (0.14) a \\ Trunk inclination 1 (°) & 9.00 (4.77) & 9.02 (7.98) & 9.00 (5.07) & 9.80 (5.77) \\ Trunk inclination 2 (°) & 7.45 (3.67) & 12.78 (6.07) a & 14.28 (6.76) b & 17.50 (6.39) b \\ Body inclination 1 (°) & 11.66 (6.46) & 6.37 (4.49) a & 12.62 (5.56) a & 25.26 (6.83) a \\ Body inclination 2 (°) & 9.66 (4.27) & 12.98 (5.99) & 11.15 (4.75) & 15.42 (5.76) a \\ \hline \hline \end{tabular} Note: a, b and c superscripts denote statistical differences (\(p\) < 0.05) from first, second or third left column.  
\end{table} 
Table 1: Segmental kinematics—mean (standard deviation)—of competitive swimmers when transiting from underwater to surface swimming in all four strokes. Figure 2: Relationships between the kinematic, segmental and coordination variables with average velocity of the competitive swimmers in the pre-transition (**a**) and transition (**b**) of the push start. Note: * denotes correlations at a \(p\) < 0.05 level. Backward regression analysis of pre-transition phase performance revealed that the body position parameters did not statistically predict (\(p>0.05\)) the average velocity in this phase.