Objectives Interoception plays an important role in maintaining body homeostasis, which is closely associated with emotional health and the function of the autonomic nervous system (ANS). Tai Chi Chuan (TCC), as a typical mindfulness-based movement, is an effective integrative practice to alleviate negative emotions. This study aimed to explore the mediating role of different dimensions of interoception between TCC and emotional health.

Method This study employed quasi-experimental design with pre-test and post-test pattern. The sample included 86 college students, 50 in the TCC group and 36 in the control group. The DepressionAnxiety Stress Scales (DASS) was administered at baseline and 12-week follow-up to evaluate negative emotions, while three dimensions of interoception, interoceptive sensibility (IS), interoceptive accuracy (IAc) and interoceptive awareness (IAw)，were measured by the Multidimensional Assessment of Interoceptive Awareness (MAIA), heartbeat counting task and confidence rating, respectively. Additionally, heart rate variability (HRV) during the abdominal breathing state at baseline and 12-week follow-up was collected.

Results At follow-up, the TCC group showed decreased anxiety levels, increased IS and IAw, and increased HR从while the control group showed increased DASS total score and score increases on all DASS sub-subscales. In the TCC group, increased IS was correlated with decreased negative emotions and increased HRV parameters. Moreover, the change in IS

mediated the relationship between TCC intervention and decreased anxiety. Conclusions These findings suggest that IS might be one of the mechanisms of decreased anxiety after TCC intervention. It also sheds light on the clinical intervention of emotional disorders from an entirely new perspective.

Preregistration This study is not pre-registered.