Li Yirong, Cai Jianguang, Yu Haiyong
School of Physical Education, Hunan University of Science and Technology, Xiangtan, Hunan, China.
Front Public Health. 2025 Jul 16;13:1643510. doi: 10.3389/fpubh.2025.1643510. eCollection 2025.
Amid global aging and digital transformation, the dual effects of Internet use on health-its potential benefits and risks-remain a subject of debate. This study investigates the threshold effects of Internet use, the mediating role of physical activity, and the implications for digital health policy in China, revealing a compensation-vulnerability paradox among disadvantaged groups.
The data were drawn from the 2020 China Family Panel Studies (CFPS), a nationally representative sample comprising 7,308 adults aged ≥45. We conducted multivariable regression with robustness checks and bootstrap mediation analysis. Nonlinear sensitivity was tested via U-shaped relationship validation and threshold effect identification.
Moderate Internet use (below 4.8 h/day) confers health benefits, but excessive use leads to adverse outcomes. Physical activity serves as a partial mediator in this relationship, exhibiting nonlinear mediation dynamics. Although the current average of 1.8 h/day of use internet is well below the harmful threshold, structural digital exclusion creates a compensation-vulnerability paradox: older and less-educated groups derive greater marginal health benefits from moderate use but face higher risks of overuse due to limited digital literacy and physiological constraints.
Internet use offers conditional health benefits for older adults, contingent on usage thresholds and mediated by physical activity. Policymakers must balance targeted digital inclusion with safeguards against overuse, particularly for vulnerable groups. These findings highlight the need for time-bound digital health interventions and literacy programs to address the paradox of technological compensation and vulnerability, informing digital health policy in aging societies.
在全球老龄化和数字转型的背景下，互联网使用对健康的双重影响——其潜在益处和风险——仍是一个有争议的话题。本研究调查了互联网使用的阈值效应、身体活动的中介作用以及对中国数字健康政策的影响，揭示了弱势群体中的补偿 - 脆弱性悖论。
数据来自2020年中国家庭追踪调查（CFPS），这是一个具有全国代表性的样本，包括7308名年龄≥45岁的成年人。我们进行了稳健性检验的多变量回归和引导中介分析。通过U型关系验证和阈值效应识别来测试非线性敏感性。
适度使用互联网（每天低于4.8小时）对健康有益，但过度使用会导致不良后果。身体活动在这种关系中起部分中介作用，呈现非线性中介动态。尽管目前每天平均1.8小时的互联网使用时间远低于有害阈值，但结构性数字排斥造成了补偿 - 脆弱性悖论：年龄较大和受教育程度较低的群体从中度使用中获得更大的边际健康益处，但由于数字素养有限和生理限制，面临更高的过度使用风险。
互联网使用对老年人的健康有益，但取决于使用阈值并由身体活动介导。政策制定者必须在有针对性的数字包容与防止过度使用之间取得平衡尤其是对弱势群体而言。这些发现凸显了有时间限制的数字健康干预措施和素养计划的必要性，以解决技术补偿和脆弱性的悖论，为老龄化社会的数字健康政策提供参考。
