Over the course of history, female monastic populations were the only community of women that were free to make their own decisions regarding administration and finances. Many nunneries produced their own food, wine and olive oil, making income out of that and being self-sustaining. The Constitution of the Nuns gives very detailed rules about every aspect of the life in a monastery. The main tasks were praying, contemplation and manual labour. The importance and the necessity of work were emphasized, although it is not specified what kind of work it had to be. On the contrary, according to Rey, Spanish monasteries were more centres of consumption than of production. This claim was established on the basis of her study of monasteries expense books, as well as on the fact that nuns were of noble status and probably not used to work. In Rey’s opinion, most of the work was performed by lay sisters, who were employed in the external service of the convent and belonged to lower social status. In order to test this claim skeletal markers of activity and repetitive traumas, such as entheseal changes, Schmorl's nodes, Charles’ facet, squatting facets, spinal disc hernias, jumper knee, os acromiale and markers of occupational stress on teeth were analysed and compared between three monastic and three female secular populations, geographically and chronologically close to each other. The obtained results proved that occupational markers were mainly equally presented in monastic and secular populations (or in some cases even more presented in the monastic populations), which can lead to the conclusion that nuns did perform physical labour, probably starting in the non-adult period.