The maximal running speed (MRS) achieved in the 30-15 International Fitness Test (30-15IFT) is widely used to prescribe high-intensity interval training (HIIT). The 30-15IFT can be performed in either 40- (30-15IFT-40) or 28-meters (30-15IFT-28) length. Objectives: The aim of this study was to evaluate the MRS achieved in the 30-15IFT-40 and the 30-15IFT-28. Methods: Fifty U-18 players from different sports (handball: n=19, soccer: n=19, tennis n=12) attended two testing sessions. Results: MRS did not differ between the 30-15IFT-40 and the 30-15IFT-28 in either handball or soccer players. However, tennis players showed significantly greater MRS values in the 30-15IFT-28 than in the 30-15IFT-40 (20.80±1.87 vs 20.05±2.09 km·h-1; p = 0.030; ES = 0.38). In addition, tennis player showed significant greater MRS in the 30-15IFT-28 (20.80±1.87 km·h-1) than both handball (18.58±1.13 km·h-1; p < 0.001; ES = 1.53) and soccer players (18.74±0.93 km·h-1; p = 0.001; ES = 1.47). Conclusions: The different MRS values in the 30-15IFT-40 and the 30-15IFT-28, entail significant practical implications for HIIT prescription in tennis players.

中文翻译：

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30-15 岁国际体能测试中使用的长度（40 米与 28 米）是否会影响来自不同运动项目的 18 岁以下运动员的最大跑步速度？

在 30-15 国际体能测试 (30-15IFT) 中达到的最大跑步速度 (MRS) 被广泛用于规定高强度间歇训练 (HIIT)。30-15IFT 可以在 40- (30-15IFT-40) 或 28- 米 (30-15IFT-28) 长度下进行。目的：本研究的目的是评估在 30-15IFT-40 和 30-15IFT-28 中实现的 MRS。方法：来自不同运动项目（手球：n=19，足球：n=19，网球 n=12）的 50 名 U-18 球员参加了两次测试。结果：手球或足球运动员的 30-15IFT-40 和 30-15IFT-28 之间的 MRS 没有差异。然而，网球运动员在 30-15IFT-28 中的 MRS 值显着高于 30-15IFT-40（20.80±1.87 vs 20.05±2.09 km·h-1；p = 0.030；ES = 0.38）。此外，网球运动员在 30-15IFT-28 (20.80±1. 87 km·h-1) 比手球运动员 (18.58±1.13 km·h-1; p < 0.001; ES = 1.53) 和足球运动员 (18.74±0.93 km·h-1; p = 0.001; ES = 1.47)。结论：30-15IFT-40 和 30-15IFT-28 中不同的 MRS 值对网球运动员的 HIIT 处方具有重要的实际意义。