The fashion industry is known for its negative environmental and social impacts globally. Sustainability has become a priority for governmental agendas and concerned consumers. However, achieving sustainability remains a challenge for the industry due to its complex supply chains and systems. Specifically, the footwear industry accounts for 1.4% of global carbon emissions, with trainers being one of the most popular types of footwear among consumers. Recent studies have highlighted their ecological footprint, prompting companies to implement various actions to address this issue. Nevertheless, the environmental impact of this sector continues to pose significant challenges. This paper conducts a content analysis to examine and classify the actions taken by 13 Sustainable Trainers’ Brands according to five categories: Sustainable Materials, Sustainable Manufacturing, Sustainable Distribution, End-of-Life Recovery, and Eco-Design. Results show that Sustainable Materials is the most frequently adopted approach for sustainability, while Eco-Design is the least emphasised area. Additionally, the indicators used to assess sustainability in this sector primarily focus on the Environmental Sphere, with Sustainable Materials being the most prominently coded category. This study identifies Eco-Design as an area that requires further attention in future developments to address sustainability from a broader perspective.