This is the first study to measure the 'sense of community' reportedly offered by the CrossFit gym model.A cross-sectional study adapted Social Capital and General Belongingness scales to compare perceptions of a CrossFit gym and a traditional gym. CrossFit gym members reported significantly higher levels of social capital (both bridging and bonding) and community belongingness compared with traditional gym members. However, regression analysis showed neither social capital, community belongingness, nor gym type were independent predictors of gym attendance. Exercise and health professionals may benefit from evaluating further the 'sense of community' offered by gym-based exercise programmes. KeywordsCommunity health psychology, social capital, exercise behaviour, physical activity, social support.