Table 1
Mean values and standard deviations (SDs) of lower limb power parameters assessed in the CMJ test and results of special 50 m trials before (PRE) and after (POST) the water rescue course
| Variable | PRE (Mean ± SD) | POST (Mean ± SD) | Difference (POST–PRE) | % changes | t | p-value | Cohen’s d |
|---|---|---|---|---|---|---|---|
| JH (cm) | 20.14 ± 2.35 | 21.85 ± 3.46 | 1.71 | 8.47% | 2.98 | 0.008* | 0.685 |
| TOF (N) | 0.71 ± 0.23 | 0.88 ± 0.36 | 0.17 | 23.42% | 3.13 | 0.006* | 0.72 |
| LF (N) | 1.03 ± 0.33 | 1.09 ± 0.29 | 0.05 | 5.20% | 0.95 | 0.354 | 0.218 |
| MCP (W·kg−1) | 2.28 ± 0.48 | 2.47 ± 0.44 | 0.20 | 8.72% | 2.13 | 0.047* | 0.489 |
| MV (m/s) | 2.04 ± 0.23 | 2.10 ± 0.22 | 0.06 | 2.81% | 2.63 | 0.017* | 0.605 |
| TOV (m/s) | 1.84 ± 0.15 | 1.91 ± 0.17 | 0.07 | 3.77% | 2.50 | 0.022* | 0.574 |
| 50 m freestyle (s) | 42.34 ± 5.83 | 40.16 ± 5.35 | −2.18 | −5.15% | −1.34 | 0.249 | −0.603 |
| 50 m rescue crawl (s) | 44.84 ± 7.17 | 42.95 ± 6.42 | −1.89 | −4.23% | −2.77 | 0.013* | −0.636 |
| 50 m kick (s) | 77.92 ± 10.88 | 73.65 ± 10.70 | −4.27 | −5.48% | −5.06 | < 0.001* | −1.161 |
| Two-handed towing (s) | 105.18 ± 25.63 | 97.51 ± 20.83 | −7.68 | −7.30% | −3.25 | 0.004* | −0.746 |
| One-handed chin tow (s) | 103.44 ± 16.38 | 97.86 ± 13.50 | −5.58 | −5.40% | −4.35 | < 0.001* | −0.999 |
| Cross-chest tow (s) | 102.72 ± 14.59 | 98.72 ± 12.54 | −4.00 | −3.89% | −3.07 | 0.006* | −0.706 |
JH, jump height; TOF, take-off force; LF, landing force; MCP, maximal concentric power; MV, maximal velocity; TOV, take-off velocity; t, Student’s t-test, p-value; effect size (d), * – statistically significant differences, 50 m kick – legs-only breaststroke kick in the supine position.
Figure 1
Regression models for aquatic performance. (a) Regression coefficients for the 50 m kick and two-handed towing models. (b) Observed versus predicted values for the two-handed towing model.
Figure 2
Cluster profiles based on standardized POST variables. Cluster 0 – higher CMJ performance; Cluster 1 – higher aquatic task performance. JH – jump height; MCP – maximal concentric power; MV – maximal velocity.