The purpose of this study was to investigate sex differences in motor performance and anaerobic peak power in children. Furthermore, the relationship between power-associated variables and motor performance was also examined. Ninety-four Japanese primary school children aged 11 to 12 years volunteered. Grip strength, repeated lateral jumps, 50-m sprint, and standing broad jump were assessed following the guidelines published by the Japanese Ministry of Education and Science. Anaerobic peak power was assessed based on 6 sec sprint cycling with 4% of body mass as the braking load. The absolute peak power and peak power normalised by body mass were calculated as power-associated variables. The correlation analysis revealed that normalised peak power was moderately and strongly correlated with 50-m sprint time in both sexes, indicating the possibility that the sex difference in sprint performance could be derived from the discrepancy in anaerobic peak power. Sex differences were found in normalised peak power, lateral jumps, and 50-m sprint time. However, absolute peak power and standing broad jump did not differ significantly, and the results were not consistent with those of previous studies that examined participants in a different age range. The non-significant results in terms of absolute peak power and standing broad jump distance suggested the notion that sex differences in some variables fluctuate depending on the participants’ age. Therefore, future studies are required to investigate the sex differences in motor performance and anaerobic peak power in children of different age groups.

中文翻译：

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日本11-12岁小学生运动表现和无氧峰值功率的性别差异

本研究的目的是调查儿童运动能力和无氧峰值功率的性别差异。此外，还检查了与功率相关的变量和运动性能之间的关系。94 名 11 至 12 岁的日本小学生自愿参加。握力、重复横向跳跃、50 米冲刺和站立跳远根据日本教育和科学部发布的指南进行评估。无氧峰值功率是基于以 4% 的体重作为制动负荷进行 6 秒的冲刺骑行来评估的。由体重归一化的绝对峰值功率和峰值功率被计算为功率相关变量。相关分析表明，归一化峰值功率与两性的 50 米冲刺时间呈中度和强相关性，表明冲刺表现的性别差异可能源于无氧峰值功率的差异。在标准化峰值功率、横向跳跃和 50 米冲刺时间方面发现了性别差异。然而，绝对峰值功率和站立跳远没有显着差异，结果与之前对不同年龄范围参与者进行的研究不一致。绝对峰值功率和站立跳远距离方面的非显着结果表明，某些变量的性别差异会根据参与者的年龄而波动。因此，未来的研究需要调查不同年龄组儿童运动表现和无氧峰值功率的性别差异。