Table 2.
Changes in selected biochemical indicators of blood and physical fitness in young soccer players (n = 24) during a one-year training cycle.
| Time-Point | T1 | T2 | T3 | T4 | ICC | α |
|---|---|---|---|---|---|---|
| 25(OH)D (ng/mL) | 35.0 ± 6.26 | 24.5 ± 4.89 * | 26.4 ± 15.32 * | 40.5 ± 6.86 *,#,† | 0.38 | 0.81 |
| Ca (mg/dL) | 9.5 ± 0.28 | 10.0 ± 0.24 * | 9.8 ± 0.29 *,# | 9.8 ± 0.30 * | 0.62 | 0.82 |
| P (mg/dL) | 3.8 ± 0.47 | 4.3 ± 0.53 * | 4.1 ± 0.52 | 3.9 ± 0.58 | 0.73 | 0.79 |
| PTH (mg/mL) | 39.3 ± 15.99 | 32.4 ± 15.86 * | 39.8 ± 10.89 # | 32.8 ± 11.06 † | 0.81 | 0.85 |
| PACER (m) | 2379 ± 174.9 | 2473 ± 201.1 | 2473 ± 241.6 | 2423 ± 173.6 | 0.92 | 0.94 |
| VO2max (ml/kg/min) | 57.6 ± 2.62 | 58.7 ± 2.89 | 58.7 ± 3.35 | 58.1 ± 2.26 | 0.92 | 0.94 |
| 10m (s) | 1.75 ± 0.05 | 1.73 ± 0.05 | 1.73 ± 0.05 | 1.71 ± 0.06 * | 0.81 | 0.84 |
| 30m (s) | 4.24 ± 0.13 | 4.21 ± 0.15 | 4.19 ± 0.11 | 4.12 ± 0.12 * | 0.89 | 0.95 |
| SJ (cm) | 38.0 ± 3.68 | 37.9 ± 4.30 | 37.9 ± 3.47 | 38.0 ± 3.92 | 0.88 | 0.87 |
| CMJ (cm) | 45.9 ± 3.30 | 44.2 ± 4.85 | 44.6 ± 3.93 | 45.9 ± 3.65 | 0.88 | 0.92 |
| 10 jumps (cm) | 40.7 ± 3.24 | 39.4 ± 3.89 | 39.4 ± 3.29 | 40.4 ± 2.78 | 0.85 | 0.86 |
* Significantly different from T1; # significantly different from T2; † significantly different from T3; Ca—calcium; P–phosphorus; PTH—parathyroid hormone; SJ—squat jump; CMJ—counter movement jump; ICC—interclass correlation coefficient; α—Cronbach’s alpha.