Objective: The aim of the study was to verification the hypotheses about the relationship of trauma suffered in early childhood, alexithymia and dissociation with the power of the body self. Furthermore, it was examined whether regular physical activity as well as its type may affect the power of the body self. Material and method: The study involved 56 persons – 31 women (55.4%) (average age: M = 31.7) and 25 men (44.6%) (average age: M = 35.3). The subjects were divided into three groups: persons beginning yoga practice, persons starting exercises to improve their fitness (gym) and persons who were not taking any regular physical exercise. Self-description questionnaires were used to assess the intensity of: trauma – the Traumatic Experiences Checklist (TEC), alexithymia – the Toronto Alexithymia Scale (TAS-20), dissociation – the Curious Experiences Survey (CES) as well as a questionnaire for the body self. The assessment was conducted twice: after the recruitment of a given participant and after 3 months from the end of the first stage. Results: It was established that trauma, alexithymia and dissociation are significant predictors of the power of the body self in the study group. Emotional neglect and emotional abuse were demonstrated to have a particularly strong impact. In the case of alexithymia, the difficulty in identifying emotions and the difficulty in verbalising them were highly relevant with respect to the power of the body self. Dissociation had a significant impact on the power of the body self. As a result of physical activity, the power of the body self underwent statistically significant change as far as the interpretation of sensations in terms of emotions was concerned and the effect was greater in the group of persons practising yoga. Discussion: The results obtained not only shed new light on the pathogenic influence of trauma, alexithymia and dissociation on the power of the body self, but also demonstrated that a particular form of physical activity can, by increasing the level of interoception, change the power of the body self with respect to the ability to distinguish emotions from physical sensations. Conclusion: Traumatic experiences in early childhood become the basis for fostering permanent defence mechanisms: alexithymia and dissociation. It is these mechanisms, not the traumatic experience itself, which contribute to the development of the disorders of the body self. As it is clear from the analysis, the greatest role in this process is attributable to the difficulties in identifying emotions and depersonalisation.