Table 1.
Variable statistics of Bologna and Russi Calcio for each category.
| Variable | Bo U12 (18) | Ru U12 (16) | Bo U13 (27) | Ru U13 (12) | Bo U14 (30) | Ru U14 (21) | Bo U15 (23) | Ru U15 (15) | ∆ U12 | ∆ U13 | ∆ U14 | ∆ U15 | ||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Mean (±SD) | Mean (±SD) | Mean (±SD) | Mean (±SD) | Mean (±SD) | Mean (±SD) | Mean (±SD) | Mean (±SD) | t | p | t | p | t | p | t | p | |
| Age | 11.38 (0.36) | 11.37 (0.28) | 12.35 (0.25) | 12.37 (0.33) | 13.44 (0.24) | 13.49 (0.26) | 14.36 (0.31) | 14.43 (0.34) | 0.10 | 0.918 | −0.189 | 0.849 | −0.781 | 0.443 | −0.612 | 0.541 |
| Weight (Kg) | 41.30 (7.10) | 39.59 (8.41) | 43.89 (6.15) | 48.42 (8.35) | 52.98 (8.04) | 52.43 (11.08) | 62.79 (9.04) | 58.63 (13.19) | 0.634 | 0.530 | −1.896 | 0.066 | 0.213 | 0.841 | 1.154 | 0.261 |
| Height (cm) | 153.00 (8.20) | 142.50 (4.77) | 154.96 (7.63) | 153.90 (9.47) | 165.91 (8.28) | 160.93 (8.31) | 173.30 (8.99) | 169.77 (7.92) | 4.423 | <0.001 * | 0.372 | 0.711 | 2.112 | 0.039 * | 1.214 | 0.223 |
| BMI (kg/m2) | 17.54 (1.75) | 19.42 (3.70) | 18.21 (1.53) | 20.36 (2.73) | 19.14 (1.52) | 20.11 (3.31) | 20.88 (2.55) | 20.21 (3.38) | −1.932 | 0.062 | −3.149 | 0.003 * | −1.412 | 0.163 | 0.700 | 0.491 |
| Rel. arm circum. (cm) | 20.88 (2.00) | 22.04 (3.23) | 21.20 (1.58) | 23.76 (2.27) | 22.94 (1.94) | 24.09 (2.88) | 24.32 (1.73) | 24.54 (3.27) | −1.274 | 0.212 | −4.060 | <0.001 * | −1.701 | 0.104 | −0.266 | 0.789 |
| Cont. arm circum. (cm) | 22.24 (2.00) | 23.36 (3.25) | 23.24 (1.76) | 25.38 (2.04) | 25.12 (2.13) | 26.10 (3.42) | 26.66 (3.52) | 26.41 (3.39) | −1.224 | 0.229 | −3.331 | 0.002 * | −1.251 | 0.223 | 0.212 | 0.831 |
| Calf circum. (cm) | 30.57 (2.51) | 31.13 (3.29) | 30.94 (4.06) | 33.25 (2.28) | 33.99 (4.48) | 33.69 (2.93) | 34.55 (2.38) | 34.93 (3.28) | −0.560 | 0.579 | −1.791 | 0.074 | 0.267 | 0.789 | −0.412 | 0.691 |
| Thigh circum. (cm) | 40.86 (3.49) | 44.11 (5.35) | 40.84 (3.85) | 46.63 (4.00) | 45.16 (3.62) | 47.60 (5.78) | 46.28 (3.88) | 48.33 (5.77) | −2.122 | 0.041 * | −4.286 | <0.001 * | −1.861 | 0.069 | −1.319 | 0.199 |
| Humeral diameter (cm) | 5.88 (0.39) | 5.74 (0.42) | 6.11 (0.33) | 6.07 (0.50) | 6.41 (0.33) | 6.43 (0.42) | 6.71 (0.30) | 6.66 (0.41) | 0.965 | 0.342 | −4.287 | <0.001 * | −0.241 | 0.812 | 0.463 | 0.651 |
| Femoral diameter (cm) | 8.60 (0.44) | 8.94 (0.57) | 8.61 (0.51) | 8.97 (1.02) | 9.27 (0.54) | 9.35 (0.55) | 9.42 (0.46) | 9.73 (0.58) | −1.976 | 0.054 * | 0.271 | 0.789 | −0.530 | 0.603 | −1.841 | 0.071 |
| Biceps SK (mm) | 1.67 (0.38) | 1.99 (0.40) | 1.50 (0.30) | 1.92 (0.47) | 1.48 (0.28) | 1.72 (0.44) | 1.28 (0.20) | 1.56 (0.37) | −2.351 | 0.024 * | −2.878 | 0.010 * | −2.231 | 0.034 * | −2.711 | 0.010 * |
| Triceps SK (mm) # | 2.13 (0.33) | 2.36 (0.30) | 2.09 (0.21) | 2.36 (0.35) | 1.90 (0.30) | 2.22 (0.35) | 1.85 (0.28) | 2.01 (0.38) | −2.163 | 0.039 * | −2.502 | <0.017 * | −3.374 | 0.001 | −1.371 | 0.183 |
| Subscapular SK (mm) # | 1.75 (0.27) | 1.88 (0.48) | 1.67 (0.17) | 2.12 (0.34) | 1.80 (0.16) | 2.02 (0.4) | 1.88 (0.21) | 1.88 (0.32) | −0.978 | 0.345 | −4.389 | <0.001 * | −2.419 | 0.021 * | −0.011 | 0.999 |
| Supraspinal SK (mm) # | 1.79 (0.37) | 1.96 (0.54) | 1.54 (0.25) | 2.05 (0.47) | 1.57 (0.22) | 1.94 (0.48) | 1.67 (0.21) | 1.84 (0.41) | −1.113 | 0.282 | −3.491 | 0.002 * | −3.34 | <0.01 * | −1.501 | 0.153 |
| Suprailiac SK (mm) # | 2.09 (0.38) | 2.29 (0.48) | 1.96 (0.27) | 2.41 (0.35) | 2.04 (0.25) | 2.30 (0.44) | 2.06 (0.25) | 2.25 (0.33) | −1.331 | 0.202 | −3.967 | 0.001 * | −2.446 | <0.020 * | −1.902 | 0.071 |
| Thigh SK (mm) # | 2.35 (0.23) | 2.50 (0.28) | 2.27 (0.18) | 2.46 (0.33) | 2.20 (0.21) | 2.42 (0.38) | 2.12 (0.21) | 2.28 (0.37) | −1.758 | 0.091 | −1.959 | 0.067 | −2.401 | <0.022 * | −1.479 | 0.152 |
| Medial Calf SK (mm) # | 1.99 (0.39) | 2.31 (0.29) | 1.91 (0.28) | 2.23 (0.28) | 1.88 (0.28) | 2.04 (0.38) | 1.76 (0.23) | 1.96 (0.38) | −2.761 | 0.009 * | −3.243 | 0.002 * | −1.641 | 0.112 | −1.802 | 0.091 |
| Lateral Calf SK (mm) # | 2.08 (0.34) | 2.34 (0.29) | 2.00 (0.23) | 2.27 (0.27) | 2.00 (0.28) | 2.17 (0.35) | 1.92 (0.20) | 2.03 (0.38) | −2.434 | <0.05 * | −3.071 | 0.002 * | −1.839 | 0.072 | −1.011 | 0.323 |
| Total Upper area (cm3) # | 3.54 (0.20) | 3.64 (0.29) | 3.57 (0.15) | 3.78 (0.19) | 3.73 (0.17) | 3.82 (0.24) | 3.85 (0.14) | 3.85 (0.25) | −1.113 | 0.282 | −3.578 | 0.001 * | −1.511 | 0.142 | −0.110 | 0.910 |
| Upper Muscle area (cm3) | 27.98 (6.17) | 32.78 (11.24) | 28.61 (4.92) | 38.08 (8.76) | 33.75 (6.50) | 39.00 (11.26) | 38.22 (6.32) | 40.17 (13.67) | −1.567 | 0.126 | −4.334 | <0.001 * | −2.101 | 0.048 * | −0.601 | 0.550 |
| Upper Fat area (cm3) | 7.04 (0.74) | 6.69 (0.56) | 7.38 (0.68) | 7.23 (1.04) | 8.44 (0.91) | 7.82 (0.98) | 9.09 (0.81) | 8.57 (0.87) | 1.576 | 0.125 | 0.531 | 0.602 | 2.321 | 0.024 * | 1.881 | 0.070 |
| Upper Fat Index (%) § | 20.72 (4.04) | 18.20 (4.95) | 19.47 (3.48) | 16.57 (4.15) | 20.3 (2.34) | 17.51 (3.95) | 19.43 (2.05) | 18.54 (4.03) | 1.631 | 0.113 | 4.141 | <0.001 * | 3.171 | 0.002 * | 0.901 | 0.374 |
| Total Calf area (cm3) # | 4.30 (0.17) | 4.34 (0.21) | 4.32 (0.26) | 4.47 (0.14) | 4.51 (0.22) | 4.50 (0.18) | 4.55 (0.14) | 4.57 (0.18) | −0.489 | 0.618 | −2.412 | 0.023 * | 0.211 | 0.829 | −0.331 | 0.741 |
| Calf Muscle area (cm3) | 52.02 (7.78) | 48.09 (8.76) | 56.56 (18.29) | 58.60 (7.57) | 70.46 (26.86) | 63.59 (10.17) | 74.41 (10.34) | 71.85 (8.98) | 1.389 | 0.171 | −0.371 | 0.713 | 1.119 | 0.271 | 0.792 | 0.443 |
| Calf Fat area (cm3) | 22.86 (7.87) | 29.88 (10.78) | 20.93 (5.92) | 29.81 (8.76) | 23.05 (7.38) | 27.43 (11.21) | 21.07 (5.23) | 26.07 (12.34) | −2.184 | 0.041 * | −3.729 | <0.001 * | −1.690 | 0.104 | −1.732 | 0.093 |
| Calf Fat index (%) § | 29.95 (7.78) | 37.66 (7.21) | 27.60 (6.51) | 33.34 (6.89) | 25.01 (6.33) | 29.50 (8.38) | 22.03 (3.92) | 25.62 (7.38) | −2.983 | 0.005 * | −2.503 | 0.022 * | −2.182 | 0.034 * | −1.959 | 0.064 |
| Total Thigh area (cm3) | 133.81 (22.36) | 157.02 (37.82) | 133.96 (23.17) | 174.31 (29.36) | 163.36 (26.38) | 182.96 (44.42) | 171.66 (28.2) | 188.47 (46) | −2.211 | 0.034 * | −4.532 | <0.001 * | −1.973 | 0.052 * | −1.401 | 0.170 |
| Thigh Muscle area (cm3) | 120.80 (22.20) | 144.45 (35.58) | 120.27 (22.44) | 160.63 (30.37) | 147.85 (25.46) | 168.88 (45.21) | 155.26 (27.49) | 172.99 (46.97) | −2.221 | 0.034 * | −4.638 | <0.001 * | −2.119 | 0.040 * | −1.472 | 0.155 |
| Thigh Fat area (cm3) | 13.02 (1.14) | 12.57 (1.40) | 13.69 (1.83) | 13.68 (1.99) | 15.51 (1.71) | 14.09 (2.88) | 16.40 (1.65) | 15.48 (2.18) | 1.041 | 0.313 | 0.010 | 0.999 | 2.209 | 0.037 * | 1.492 | 0.153 |
| Thigh Fat index (%) § | 10.00 (1.87) | 8.55 (2.50) | 10.39 (1.43) | 8.15 (2.22) | 9.64 (1.22) | 8.20 (2.56) | 9.72 (1.22) | 8.72 (2.40) | 1.909 | 0.0644 | 3.789 | <0.001 * | 2.678 | 0.010 * | 1.701 | 0.103 |
| Fat Mass (kg) # | 1.72 (0.43) | 1.87 (0.52) | 1.74 (0.23) | 2.16 (0.43) | 1.77 (0.26) | 2.04 (0.46) | 1.76 (0.40) | 1.84 (0.53) | −0.849 | 0.404 | −3.191 | <0.005 * | −2.421 | 0.021 * | −0.454 | 0.661 |
| Fat Free Mass (kg) | 35.21 (5.44) | 32.32 (5.58) | 38.02 (5.14) | 39.02 (6.17) | 46.92 (7.44) | 43.86 (8.67) | 56.50 (7.63) | 51.39 (9.53) | 1.526 | 0.137 | −0.531 | 0.602 | 1.348 | 0.181 | 1.829 | 0.082 |
| %FM § | 14.34 (3.94) | 17.54 (5.61) | 13.29 (1.98) | 18.98 (5.71) | 11.50 (2.73) | 15.94 (5.99) | 9.89 (3.11) | 11.74 (4.82) | −1.913 | 0.054 * | −3.362 | <0.001 * | −3.172 | <0.001 * | −6.941 | <0.001 * |
| Phase Angle # | 1.73 (0.10) | 1.76 (0.05) | 1.89 (0.14) | 1.78 (0.06) | 1.82 (0.08) | 1.80 (0.13) | 1.90 (0.08) | 1.91 (0.29) | −1.256 | 0.224 | 3.544 | 0.001 * | 0.421 | 0.681 | −0.192 | 0.851 |
| R/H (Ω/m) | 412.09 (64.21) | 511.44 (71.74) | 382.83 (49.22) | 383.34 (63.66) | 330.14 (48.38) | 359.60 (65.37) | 304.38 (45.02) | 312.73 (59.93) | −3.876 | <0.001 * | −0.021 | 0.982 | −1.848 | 0.072 | −0.492 | 0.633 |
| Xc/H (Ω/m) | 41.73 (6.74) | 51.43 (5.14) | 44.42 (6.16) | 40.03 (7.74) | 35.55 (4.60) | 38.05 (6.58) | 35.36 (4.66) | 36.73 (4.72) | −4.666 | <0.001 * | 1.879 | 0.072 | −1.601 | 0.119 | −0.878 | 0.391 |
| YOYO test (s) | / | / | / | / | 2367.40(536.90) | 787.80 (461.90) | 2500.00 (598.90) | 1702.90 (551.30) | / | / | / | / | 10.198 | <0.001 * | 3.871 | <0.001 * |
| CMJ test (cm) | 27.99 (2.88) | 24.04 (5.13) | 28.63 (3.86) | 24.24 (4.78) | 32.77 (2.99) | 27.93 (6.27) | 36.60 (6.15) | 28.57 (4.53) | 2.81 | <0.01 * | 2.941 | 0.005 * | 3.687 | <0.001 * | 4.343 | <0.001 * |
| Sprint 15 m test (s) | 2.71 (0.12) | 3.18 (0.19) | 2.83 (0.11) | 3.07 (0.19) | 2.51 (0.93) | 2.94 (0.23) | 2.41 (0.12) | 2.76 (0.13) | −8.6 | <0.001 * | −4.812 | <0.001 * | −9.212 | <0.001 * | −8.732 | <0.001 * |
| RSA 20 + 20 m (s) | 6.34 (0.22) | 7.22 (0.42) | 6.57 (0.19) | 6.88 (0.39) | 5.84 (0.19) | 6.64 (0.49) | 5.69 (0.20) | 6.20 (0.22) | 7.27 | <0.001 * | −3.042 | 0.004 * | 2.031 | 0.001 * | −6.592 | <0.001 * |
Note: Bo, F.C. Bologna.; Ru, U.S. Russi; U12, Under 12; U13, Under 13; U14, Under 14; U15, Under 15; t, student’s t; p, p-value; circum, circumference; rel, relaxed; cont, contracted; SK, skinfold; CMJ, counter movement jump; RSA, repeated sprint ability; SD, standard deviation; * statistically significant; ∆ difference between; # logarithmic scale; § proportion analysis with the Z-test.