Though statistics is covered in secondary-school curricula, it is usually limited to few lessons and mainly taught in a procedural approach. There seems to be a gap between the education of mathematics teachers and the demands on their practice. Learning statistics from a mathematical perspective does not qualify to teach the subject properly. Therefore, we developed a pedagogical intervention that consists in a training program for teaching aimed at mathematics pre-service teachers and focused on activity-based learning. Two workshops and a web-site were designed: first, to improve competencies in teaching statistics at secondary level, and second, to positively influence attitudes towards statistics. Workshops about descriptive statistics and probability were focused on real-data analysis from media, games, and simulations. Over several years, more than 500 teachers attended these workshops, which were positively evaluated in terms of content, relevance, and applicability. A follow-up survey 2-5 years later showed that most teachers are teaching statistics in their classes, which can be seen as great step forward to bring statistics into the classroom.