Physical fitness self-concept (PFSC) is an important predictor of motivation and physical activity in children. Recent studies revealed that not only PFSC but also its interplay with perceptions of one’s ideal and ought physical fitness self are related to motivation and physical activity. As the meaning of ideal and ought selves in children is yet unclear, this study aimed to investigate how PFSC, ideal physical fitness self, and ought physical fitness self are related to children’s motivation and physical activity. Six hundred forty-five children (M_age = 8.87 years) filled out questionnaires twice with an interval of approximately 8 months. Polynomial regression with response surface analyses and mediation analyses was conducted. Results showed that PFSC, rather than ideal and ought self-perceptions, is associated with autonomous motivation, self-efficacy, and physical activity. The relationship between PFSC and physical activity was mediated by self-efficacy. Findings indicate that physical activity promotion programs should include PFSC and self-efficacy enhancement in childhood.

身体健康自我概念 (PFSC) 是儿童动机和身体活动的重要预测指标。最近的研究表明，不仅 PFSC，而且它与一个人的理想和应该的身体健康自我认知的相互作用都与动机和身体活动有关。由于儿童理想自我和应该自我的含义尚不清楚，本研究旨在探讨 PFSC、理想身体健康自我和应该身体健康自我与儿童动机和身体活动的关系。六百四十五名儿童（M_岁 = 8.87 岁) 两次填写问卷，间隔约 8 个月。进行多项式回归与响应面分析和调解分析。结果表明，PFSC 与自主动机、自我效能和身体活动有关，而不是理想和应该的自我认知。PFSC 与体力活动之间的关系由自我效能调节。研究结果表明，身体活动促进计划应包括儿童时期的 PFSC 和自我效能增强。