Clinical trials

The goal of this feasibility cluster randomized trial is to determine whether a future large pragmatic cluster randomized controlled trial can be conducted to evaluate the effects of a nature-based intervention on children's mental and physical health. The intervention will be delivered in preschools located in or near public housing areas and compared with usual activities in similar preschools. The main questions it aims to answer are: * Are parents willing to participate in follow-up assessment using the Strengths and Dif-ficulties Questionnaire (SDQ)? * Can participants be successfully recruited, and can the nature-based intervention be delivered as intended? * Is it possible to gather data on children's motor development, physical activity, sleep, absenteeism, and stress, and on stress and absenteeism among educators and parents? * Is the intervention safe and acceptable for children, parents, and educators? Researchers will compare a 14-week nature-based intervention with usual preschool activities. The nature-based intervention is based on the Danish Outdoor Council's Green Sprouts ("Grønne Spirer") programme and focuses on using nature for play and learning. The intervention is being developed together with educators and children and includes nature-based activities designed to support motor development, physical activity, and positive interactions between children. Participants will: * Take part in either the nature-based intervention or usual preschool activities. * Complete questionnaires about child well-being, quality of life, and parental stress. * Participate in assessments of fine and gross motor skills. * Wear an activity monitor to measure physical activity and sleep. * Provide hair samples for measurement of stress-related hormones. * Take part in interviews and observations. The study will include approximately 56 children aged 4 to 6 years, their parents, and approx-imately 15 educators. The results will help determine whether the intervention can be implemented in preschools as currently designed and will inform the planning of a future large cluster-randomized controlled trial. No major risks are expected. Participants may experience minor discomfort when a small hair sample is collected for stress measurement.