Table 2. Analysis of performance variables of the front crawl tumble turn according to skill level. Data are means (SD).
Sub-elite swimmers
(n = 9)
Elite swimmers
(n = 9)
IC (95%) Effect size (d) p-value
Turn time (3mRTT, s) 3.15 (0.11) 2.89 (0.07) (-0.35:-0.18) 3.05 0.000
Maximal speed (Vmax, m/s) 2.34 (0.22) 2.58 (0.17) (0.05:0.43) -1.03 0.015
Speed 3 m before the wall (VIn, m/s) 1.54 (0.22) 1.75 (0.23) (-0.42:0.01) 1.06 0.057
Approach time (AT, s) 1.23 (0.08) 1.09 (0.06) (-0.20:-0.06) 1.88 0.001
Speed 1 m before the rotation (V1mR, m/s) 1.57 (0.13) 1.73 (0.13) (-0.28:-0.04) 1.70 0.013
Speed at the end of push-off (VG, m/s) 2.31 (0.22) 2.55 (0.15) (0.21:0.68) -1.06 0.011
Head-wall distance when speed goes to 2.2 m/s (D22, m) 1.86 (0.16) 2.31 (0.32) (0.18:0.48) -1.59 0.001
Speed 3 m after the turning wall (VOut, m/s) 1.68 (0.12) 2.01 (0.19) (0.18:0.48) -2.05 0.000
Lower limb extension index at the end of push-off (GLLei) 0.97 (0.07) 1.04 (0.07) (-0.01:0.48) -0.83 0.079
Upper body extension index at beginning of push-off (PoUBei) 0.85 (0.07) 0.89 (0.06) (-0.02:0.10) -0.64 0.174
Underwater propulsion distance (UD, m) 2.29 (0.33) 2.61 (0.35) (0.01:0.64) -0.93 0.046
Head-wall distance when speed goes to 1.9 m/s (D19, m) 2.41 (0.36) 2.79 (0.38) (0.02:0.72) -0.85 0.037
Lateralization during push-off (LA,°) -1.66 (5.81) 2.54 (3.24) (-8.62:0.22) -0.83 0.057
Horizontal impulse during the push-off (HPoL, N.s) 134.54 (43.06) 171.44 (48.96) (-6.41:80.22) 0.80 0.090
Speeds (VOut, V1mR, VG, VIn, and Vmax) were horizontal speeds of the swimmers’ head.