It has been well established that plyometric and speed training have positive impacts on fitness parameters in soccer players. The aim of this study was to compare short-term effects of combined plyometric and speed training implemented in the same or separate weekly days on change of direction (COD), maximal sprinting speed (MSS), and repeated sprint ability (RSA) in young soccer players. Twenty-four male players from the same U19 soccer team were distributed into one control group (CG; n = 7, soccer training only) and two experimental groups performing plyometric and speed exercises in the same (CDG; n= 8) or separate weekly days (CWG; n= 9) during a 6-week preparation period. Very likely moderate within-group COD improvements were observed in CDG (ES -0.94 [-1.47 to -0.41]) and CWG (ES -0.97 [-1.52 to -0.42]) groups. Possibly small within-group RSA improvements were also observed in CWG (ES -0.24[-0.64 to 0.16]) and CDG (ES -0.31 [-0.79 to 0.17]) groups. CWG and CDG groups showed possibly small (ES -0.28 [-0.62 to 0.06]) and very likely moderate (ES -0.80 [-1.28 to -0.32]) within-group MSS improvements following the intervention, respectively. A likely moderate (ES 0.71 [0.03 to 1.39]) greater MSS improvement was observed in CDG group than CWG group. It is suggested to supplement normal soccer training with combined plyometric and speed exercises to improve COD, MSS, and RSA performance and implement these exercises in the same weekly session to improve MSS with a greater effect.

中文翻译：

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体力训练和速度训练相结合对年轻足球运动员方向，线速度和反复冲刺能力的影响

众所周知，测速和速度训练对足球运动员的健身参数具有积极影响。这项研究的目的是比较在同一天或每周一次进行的综合体能训练和速度训练对年轻人的方向变化（COD），最大冲刺速度（MSS）和重复冲刺能力（RSA）的短期影响足球运动员。来自同一支U19足球队的二十四名男性球员被分配到一个对照组（CG； n = 7，仅进行足球训练），两个实验组在同一组（CDG； n = 8）或每周进行一次测速和速度练习6周的准备期间内的天数（CWG; n = 9）。在CDG（ES -0.94 [-1.47至-0.41]）和CWG（ES -0.97 [-1.52至-0.42]）组中，极有可能观察到中等程度的组内COD改善。在CWG（ES -0.24 [-0.64至0.16]）和CDG（ES -0.31 [-0.79至0.17]）组中也观察到了较小的组内RSA改善。干预后，CWG和CDG组分别表现出较小的（ES -0.28 [-0.62至-0.06]）和非常可能的中等（ES -0.80 [-1.28至-0.32]）组内MSS改善。在CDG组中，与CWG组相比，MSS改善程度可能中等（ES 0.71 [0.03至1.39]）。建议在常规的足球训练中配合测速和速度训练相结合，以改善COD，MSS和RSA的表现，并在每周一次的会议中实施这些训练以改善MSS，从而产生更大的效果。[06]）和干预后极有可能出现中等程度的MSS改善（ES -0.80 [-1.28至-0.32]）。在CDG组中，与CWG组相比，MSS改善程度可能中等（ES 0.71 [0.03至1.39]）。建议在常规的足球训练中配合测速和速度训练相结合，以改善COD，MSS和RSA的表现，并在每周一次的会议中实施这些训练以改善MSS，从而产生更大的效果。[06]）和干预后极有可能出现中等程度的MSS改善（ES -0.80 [-1.28至-0.32]）。在CDG组中，与CWG组相比，MSS改善程度可能中等（ES 0.71 [0.03至1.39]）。建议在常规的足球训练中配合测速和速度训练相结合，以改善COD，MSS和RSA的表现，并在每周一次的会议中实施这些训练以改善MSS，从而产生更大的效果。