School survey.

School-based physical activity interventions are considered ideal given their potential to reach most children. They can help children achieve the recommended guidelines of 60 minutes of moderate-to-vigorous physical activity per day. The Daily Mile is a popular school-based active mile intervention with a global reach. It recommends ten core principles for successful implementation, three of which are key for effectiveness: that it is quick (15 minutes), the whole school participates, and that it takes place in the school day during lessons (excluding physical education lessons and scheduled breaks). Studies assessing the impacts of The Daily Mile do not often report implementation of the ten core principles which is crucial to identifying the potential impact and feasibility of scalable interventions in real-world settings. Our aim was to assess adherence to The Daily Mile’s ten core principles in Greater London primary schools. We created and distributed a survey to 1717 primary schools during September 2020 and achieved a 21% (n = 369/1717) response rate by September 2021. Our sample was representative of Greater London primary schools with responses from every London borough. A total of 196/369 (53%) schools reported implementing The Daily Mile but none of them reported adherence to all ten core principles. Adherence to at least 6/10 principles in various combinations was reported by 54/196 (28%) schools. Only 19/196 (10%) schools that reported implementing The Daily Mile reported adherence to the three key principles recommended for effectiveness. Despite its popularity and global reach, our findings suggest that an implementation gap exists when The Daily Mile is adopted in real-world settings which is likely to challenge its intended purpose. Further research in school settings is needed to understand factors that can improve adherence to increase the potential public health impact of The Daily Mile and other similar interventions.

以学校为基础的体力活动干预方案因其能够覆盖绝大多数儿童的潜力，被视为理想的干预模式。此类方案可帮助儿童达到每日60分钟中等至高强度体力活动的推荐标准。每日一英里（The Daily Mile）是一款广受欢迎且具有全球影响力的校内主动步行一英里干预方案，其提出了十项成功实施的核心原则，其中三项为影响干预有效性的关键要素：干预时长简短（15分钟）、全校全员参与，以及在教学日的课堂时段开展（排除体育课与既定休息时段）。现有针对“每日一英里”干预效果的研究，往往未报告其十项核心原则的落实情况，而这一信息对于判断真实场景中可推广干预方案的潜在影响与可行性至关重要。本研究旨在评估大伦敦地区小学对“每日一英里”十项核心原则的依从情况。我们于2020年9月向1717所小学发放了调研问卷，截至2021年9月，共回收有效问卷369份，有效回收率为21%（n = 369/1717）。本次调研样本覆盖伦敦所有行政区，能够代表大伦敦地区小学的整体情况。在回收的问卷中，共有196所（占比53%，196/369）小学表示已实施“每日一英里”干预，但无一所学校能够完全落实全部十项核心原则。在已实施该干预的学校中，有54所（占比28%，54/196）能够至少落实6项核心原则，且落实组合各不相同。仅有19所（占比10%，19/196）已实施该干预的学校，落实了影响有效性的三项关键原则。尽管“每日一英里”方案广受欢迎且覆盖全球，但本研究结果显示，在真实场景中推广该方案时仍存在落实缺口，这或将削弱其预设目标的实现效果。未来仍需在学校场景中开展进一步研究，以明确能够提升干预原则依从性的影响因素，从而增强“每日一英里”及其他同类干预方案的潜在公共卫生效益。