The effect of training in green space on young athletes’ sports competition anxiety: a quasi-experimental study

Alleviating athletes’ sport competition anxiety (SCA) is a widely studied scientific issue. Exposure to green space is essential for promoting mental health, and the health benefits of green exercise have been acknowledged. However, evidence on the competition mental health benefits of training in green space for athletes is insufficient. Against the backdrop of athletes resuming training after the COVID-19 pandemic, this study aimed to explore the differences in the impact of indoor training versus outdoor green space training on SCA of young athletes. We recruited 71 college athletes, with some mainly training indoors and others mainly training in outdoor environments. In March 2023 and June 2023, the Sport Competition Anxiety Test (SCAT) was conducted before the athletes’ first and second competitions, respectively. Employing a quasi-experimental design, this study utilised the Difference-in-Differences (DID) method to model the intervention group (training in outdoor green space) and the control group (training indoors). The model included various confounding variables like self-perceived green space quality and social cohesion. We conducted robustness tests using the Propensity Score Matching with Difference-in-Differences (PSM-DID) method. The research revealed three main results: (1) Outdoor green space training significantly reduced SCA compared to indoor training among athletes. (2) Athletes training in outdoor green space exhibited a significant decrease in SCA as social cohesion levels increased. (3) Indoor training athletes experienced a significant rise in SCA as their self-perceived green space quality in the training environment improved. This study offers crucial evidence to optimise athletes’ training environment and support their mental health.