Advanced capitalist societies are currently experiencing a series of widespread global public health challenges. The purpose of this research has been to explore the role of ‘fitness professionals’ in this landscape and to understand whether and how they are able to make the contribution to public health that is claimed. The research was conducted over three iterative phases of research: (1) a comprehensive literature review; (2) five complex case studies of fitness professionals in practice; and (3) interviews with twenty key stakeholders/policymakers in the health, fitness and leisure sectors. The findings show that fitness professionals are an important, complex, undervalued and precarious health-related occupational group. Based on the research evidence, it is clear that there is a gap between the health- and fitness-related needs of society and the capacity of the health, fitness and leisure sectors to serve those needs effectively. Using ‘neoliberalism’ as a framework, it is argued that the occupational group of fitness professionals appears to highlight critical gaps in the neoliberal ideology concerning whether, how and under what circumstances the state should intervene in a health-related market. Recommendations are made for improving the practice and/or the development of practice for fitness professionals in the future.