Table 4.

Countermovement jump performance (cm) grouped by soccer category, age, and year's quarter (mean ± standard deviation).

Category/Age	N	Jan–Mar	Apr–Jun	Jul–Sep	Oct–Dec	Total
U14	67	28.5 ± 5.1	25.9 ± 6.1	26.8 ± 7.7	22.2 ± 6.2	26.6 ± 6.5
13 years old	62	28.1 ± 5.5	25.9 ± 6.1	26.4 ± 7.7	22.2 ± 6.2	26.2 ± 6.7
U15	76	28.7 ± 4.6	28.9 ± 4.7	28.1 ± 4.4	29.5 ± 4.9	28.7 ± 4.5
14 years old	80	28.7 ± 4.4	28.9 ± 4.7	28.8 ± 3.8	29.5 ± 4.9	28.8 ± 4.3
U17	63	28.9 ± 5.5	29.6 ± 4.6	28.8 ± 6.4	30.5 ± 3.6	29.3 ± 5.1
15 years old	40	27.7 ± 5.5	27.8 ± 3.8	30.5 ± 6.3	31.7 ± 3.7	28.7 ± 5.2
16 years old	24	31.8 ± 4.3	31.3 ± 4.8	23.2 ± 2.8	28.4 ± 2.8	30.5 ± 4.7
U19	53	29.0 ± 4.8	35.0 ± 5.6	33.4 ± 5.3	36.1 ± 7.5	33.0 ± 6.1
17 years old	21	25.9 ± 4.3	36.0 ± 7.6	36.0 ± 5.7	37.9 ± 9.8	33.1 ± 8.2
18 years old	19	31.4 ± 3.5	35.6 ± 6.2	31.1 ± 5.3	34.1 ± 3.4	32.8 ± 4.9
19 years old	13	32.2 ± 4.3	34.1 ± 5.0	32.9 ± 1.7	32.5 ± 0.0	33.3 ± 3.8