Extensively based on fieldwork material, From Tapas to Modern Yoga primarily analyses embodied practices of ascetics belonging to four religious orders historically associated with the practice of yoga and hatha yoga. This focus on ascetics stems from the fact that yogic techniques probably developed in ascetic contexts, yet scholars have rarely focused their attention on non-international ascetic practitioners of yoga.

Creating a confrontation between textual sources and ethnographic data, the book demonstrates how 'embodied practices' (austerities, yoga and hatha yoga) over the centuries accumulated layers of meanings and practices that coexist in the literature as well as in the words of contemporary sadhus. Drawing from conversations with these interlocutors, the book demonstrates the importance of ethnographic fieldwork in shedding light on past historical developments, transmissions, contemporary reinterpretation and innovation.

The strength of the work lies in its methodological approach and in the richness of its materials: by analysing present situations through comparisons and the support of past evidence, the book not only fills an academic gap but also stimulates further research on this highly complex topic. .