Background and purpose: The research literature in physical education (PE) is placing a growing focus on the need for research that can illuminate not only the challenges PE faces but also how we can develop PE to meet the needs of all students. The activist approach aims to study future possibilities in PE, and the goal is for all young people to learn to value a physically active life. The purpose of this article is to study how the activist research approach to PE can influence students' meaningful PE experiences. The study: The project was conducted in co-ed PE among 15-year-old students (10th graders) in Norway in collaboration with teachers and students at their high school. The research group followed one class of 27 students during one semester of PE. The researchers planned, taught and evaluated the process according to the critical elements of activist research in PE. Data from diverse sources (observations, interviews, student logs, reports, etc.) were collected before, during and after the project. Findings: The study demonstrates that students' sense of meaningfulness can be developed by the activist approach. Female students in all groups found PE to be more meaningful during the project than previously. The students who disliked PE prior to the teaching period displayed the greatest improvement in terms of meaningfulness. The study shows how different aspects of the activist approach influence students' sense of meaningfulness in PE. Creating a safer class environment had an impact on students' feelings of social inclusion in PE. Broadening students' perspectives about what is possible for them by introducing new activities had a great impact on students' mastery, and co-creating the curriculum was important for their feelings of personal relevant learning. Conclusions: It is our conclusion that involving students in the curriculum-making process is of great importance to their experiences of meaningfulness in PE. Our study shows that to listen to students and broaden students' understanding of what PE can be has the potential to empower students, and to contribute to meaningful experiences in PE. In contrast to the majority of activist research, our study was conducted in co-ed PE. The need to co-construct the learning environment and question male dominance in PE is urgent in co-ed settings. We believe that co-ed PE can be an important arena for working with gender equality in schools. However, it should not be underestimated how important PE teachers' roles are. If the teachers are passive, co-ed PE can seriously undermine girls' experiences of meaningfulness in PE.