Our communication will focus on the environmental attitudes of trail runners and cyclists in the French Alps. Our research question is : to what extent are practitioners of these sports environmentally sensitive, and how is this environmental sensitivity correlated with 'ecofriendly' behaviours? Quantitative methodology was employed, relying on two questionnaires. The first pertains to trail running practices and was administered in 11 different running competitions between July 2023 and February 2024 (n = 500). The second focuses on cycling activities and was conducted among cyclists during the summer of 2023 along the route of a cycle route named La Durance à Vélo (n = 345). Both questionnaires were distributed on-site, and in a mountainous region (Hautes-Alpes department, France). Several studies indicate that practitioners of outdoor activities, especially cycling and trail-running, exhibit positive attitudes towards the environment (Campbell et al., 2021; Mehmood & Zhou, 2023) and this is reflected in more eco-friendly practices (Kil et al., 2014 ; Ribet & Brander, 2020). Unlike Anglo-Saxon literature, French literature demonstrates that environmental sensitivity alone is not sufficient to completely change one's lifestyle (Pautard, 2017; Ginsburger, 2020). Indeed, engaging in cycling or trail-running appears to environmental values are linked to high cultural capital (Cafargna et al., 2014). We hypothesize that educational level and socio-professional category influence environmental sensitivity and the likelihood of engaging in cycling or trail activities. Furthermore, we suggest that environmental values are not decisive in adopting eco-friendly practices; rather, it is cultural capital, along with adherence to a dominant ecological norm, that plays a key role.