Table 1 Strategies to optimize compliance to the study interventions

Promoting group cohesion

- Group affiliation: Chinese titles will be assigned to exercise and health education program. Each class and participant will have an arm badge to signify their group identity.

- Ice-breaking: Conduct two ice-breaking activities at the first training session to introduce the perception that they are “on the same boat” and have similar sleeping problems.

- Goal-setting: The intervener facilitates the group to set the goal of achieving mean attendance rate of not less than 85% for each 2 weeks. The bi-weekly attendance rates will be presented graphically to the group and posted in the training room.

- Group socialization: The intervener will foster communication between the participants to increase group socialization at the beginning and at the end of each training session.

Improving perceived self-efficacy

- Effective teaching: A step-by-step approach will be used to equip the individuals with the skills in conducting the intervention. The pace of teaching will be adjusted according to the participants’ learning needs. Clear instruction, demonstration, and return demonstration will be used as core teaching strategies.

- Positive evaluation: The interveners will give positive evaluative feedback and encouragement to the individuals in each session.

Emotional and tangible incentives

- Motivational incentives: Three level of certificate awards will be presented to acknowledge the participants with a mean attendance rate of > 90% attendance at the 4th week, 10th week, and 14th week. The awards are titled as Certificate of Good Participation, Certificate of Good Perseverance, Certificate of Active Star, respectively.

- Tangible incentives: A souvenir including magnifier, photo frame, coaster, sample hand cream, writing pad, or handkerchief will be provided to the awardees.