This study examines the extent to which a comprehensive, school- -based, health-education programme, based on lectures and active student participation in discussions and related project activities, can produce desirable changes in adolescents' behaviour. A quasi-experimental design, with pre- and post-intervention testing, was used in a group of adolescents (N = 858). Our results show that the conducted programme had modest effects. There was no difference between the pre- and post-intervention reports of time spent on screen-based activities and physical exercise, and the time spent doing physical activities was not correlated with the time they spent on sedentary activities. In this paper, we discuss various possible reasons for the ineffectiveness of such programmes in producing desired behavioural changes in young adolescents.

中文翻译：

---

以学校为基础的健康教育干预措施对改变青少年的屏幕和体育活动的有效性

这项研究考察了基于讲座和学生积极参与讨论以及相关项目活动的全面的，基于学校的健康教育计划可以在多大程度上改变青少年的行为。一组青少年进行了准实验设计，并进行了干预前后的测试（N = 858）。我们的结果表明，进行的程序效果不明显。干预前和干预后报告在基于屏幕的活动和体育锻炼上花费的时间之间没有差异，并且进行体育锻炼所花费的时间与他们在久坐活动上所花费的时间没有关联。在本文中，我们讨论了此类程序在产生所需青少年行为方面无效的各种可能原因。