Eight-Section Brocades Practice: The treatment group will undergo an 8-week Eight-Section Brocades intervention program consists of a total of 16 group training sessions with two 1-hour sessions per week. The treatment group participants will be provided with health qigong exercise in a group format led by qualified qigong instructors. All the health qigong instructors will be trained by a certified Traditional Chinese Medicine (TCM) practitioner with an expertise in health qigong and they are required to pass the certification examination before delivering health qigong intervention at the clinical settings. The Eight-Section Brocades protocol will be used in this study because it is easy to learn by the participants and the clinical effects on psychosocial health were evidenced in previous RCTs. A complete cycle of the Eight-Section Brocades took 12 minutes for completion, which consists of eight sequential and simple forms of movements.

To evaluate the therapeutic effects of qigong on cognitive functions, we assess a range of cognitive functions including attention, inhibition, and executive function:

Attention Network Test (ANT). The ANT is a variation from the Flanker test which assesses the efficiency of an individual's subsystems of attention (i.e. alerting, orienting, executive attention). The participants' task is to identify the direction of the central arrow by looking towards the corresponding direction, where either an upward or downward arrow will be presented. The difference of performance between the congruent and incongruent conditions represents inhibitory control ability. Neutral trials will also be presented for measuring simple attention.

Verbal fluency task (VFT). Executive functions are measured using the VFT. The experimental design of this task is adapted from previous fNIRS studies of verbal fluency where task blocks were interleaved with control blocks. Participants are required to generate exemplars of two semantic categories (i.e., animal and means of transportation) as many as possible, each for one minute, during the task blocks. This experimental task will begin with a 30-second phrase repetition period as a control, followed immediately by a 60-second task period (i.e, animal words), a 60-second control period, another 60-second task period (i.e., transportation words), and ended with another 60-second control period. The total measurement period is 270 seconds. The total number of correct and unique responses will be computed to reflect their fluency ability.

N-back Task. The N-back paradigm that assesses the updating of working memory is adapted and modified from previous neurophysiological studies that consists of 0-back (i.e., low working memory load), and 2-back (i.e., high working memory load) conditions. Each condition will be presented two times and the tasks will be performed alternately in blocks, separated by a 25-35 seconds rest block during which the participants will be instructed to relax and sit still. The order of the two task blocks will be randomized across participants to avoid order effects, and no condition will be repeated consecutively. Each target (a digit) is presented for 500 milliseconds, followed by an interstimulus interval of 1500 milliseconds. Each task block lasts for 45 seconds, and the total duration of the paradigm is 8 minutes. The accuracy rate and RT of this task will be calculated to reflect the capacity of working memory and processing speed.

The participants' depressive, anxiety, and stress symptoms were evaluated using the 21-item Depression Anxiety Stress Scale [34]. The minimum possible raw score for the depression, anxiety, and stress subscales is 0, while the maximum possible raw score is 21 with higher scores indicating a greater degree of depression, anxiety, and stress. Raw scores on the DASS-21 will need to be multiplied by 2 to calculate the final score for severity labels (normal, mild, moderate, severe, and extremely severe).