Researchers from the Department of Health and Social Sciences, Dalarna University in Falun, Sweden studied affective reactions (shifts in mood, emotional state) to Qigong.  In the past, single sessions have been associated with increased positive affect/emotional benefits.
The study used a new, modified version of the short Swedish Core Affect Scale, complemented by open-ended questions, with a group of 46 women who regularly practice Qigong, to assess changes before, during and after a Qigong session.

Affect was measured on a group and individual level.

The results showed a shift during Qigong toward increased pleasant activated and deactivated affect in the group. Inter-individual responses displayed positive affective responses, which also increased as the session proceeded for the majority of practitioners.
Acknowledging some limitations, these findings have practical implications for the enhancement of positive affect and subjective sense of well-being.

Citation:  Johansson M, Hassmén P. Affective responses to qigong: a pilot study of regular practitioners. Journal of Bodywork and Movement Therapies. 2013 Apr;17 (2): pages 177-84. [email protected]