Can a school-based lunchtime physical activity program improve mental health among autistic adolescents and their peers with ADHD in Hong Kong?

ISRCTN	ISRCTN10244024
DOI	https://doi.org/10.1186/ISRCTN10244024
Research Grants Council project number	14619720
Sponsor	Chinese University of Hong Kong
Funder	Research Grants Council, University Grants Committee

Submission date: 25/08/2026
Registration date: 27/08/2026
Last edited: 27/08/2026

Recruitment status: No longer recruiting
Overall study status: Completed
Condition category: Mental and Behavioural Disorders

Prospectively registered

Protocol

Statistical analysis plan

Results

Individual participant data

Record updated in last year

Plain English summary of protocol

Not provided at time of registration

Contact information

Prof Cindy Hui-ping Sit
Principal investigator, Scientific, Public

G06 Kwok Sports Building, The Chinese University of Hong Kong, Shatin, N.T.
Hong Kong
000000
China

ORCID ID	0000-0001-9992-7866
Phone	+852 (0)39434126
Email	sithp@cuhk.edu.hk

Dr Sima Dastamooz
Scientific, Public

Department of Paediatrics, 7/F Lui Che Woo Clinical Science Building, Prince of Wales Hospital, HK
Hong Kong
000000
China

ORCID ID	0000-0002-4972-1234
Phone	+852 (0)66792482
Email	simadastamooz@link.cuhk.edu.hk

Study information

Primary study design	Interventional
Allocation	Randomized controlled trial
Masking	Blinded (masking used)
Control	Active
Assignment	Parallel
Purpose	Prevention
Scientific title	A cluster randomised controlled trial of a 12-week school-based lunch break physical activity intervention versus usual school practice for improving mental health and reducing risk behaviours in autistic adolescents and their peers with attention-deficit/hyperactivity (ADHD) in Hong Kong
Study objectives	1. Examine the immediate, short- and longer-term effects of a school-based physical activity intervention on mental health (psychological ill-being: stress, anxiety, depression; psychological well-being: resilience, self-concept) and risk behaviours (aggression, suicidal ideation) in autistic adolescents and their peers with ADHD. 2. Assess the potential influence of moderating variables (gender, neurodevelopmental disorder [NDD] types) on the intervention effects.
Ethics approval(s)	Approved 15/01/2021, Joint Chinese University of Hong Kong New Territories East Cluster Clinical Research Ethics Committee (8/F, Lui Che Woo Clinical Sciences Building, Prince of Wales Hospital, Shatin, Hong Kong, 000000, Hong Kong; +852 (0)35053935; crec@cuhk.edu.hk), ref: 2020.451
Health condition(s) or problem(s) studied	Autism; attention-deficit/hyperactivity disorder (ADHD); adolescent mental health, including stress, anxiety, depression, resilience and self-concept; aggression and suicidal ideation
Intervention	The 12 participating secondary schools will be randomly allocated within geographic territory, using cluster randomisation at the school level, to either the school-based physical activity programme or a usual-practice control condition. Participants will enter the group allocated to their school and will not be individually randomised. Participants in intervention schools will attend group-based physical activity sessions in a school hall or gymnasium during lunch breaks. Each session will last 15 minutes and will be delivered three times per week for 12 weeks, providing 36 sessions and 540 minutes of physical activity in total. A certified fitness instructor, assisted by a trained research assistant, will deliver the sessions at an approximate staff-to-participant ratio of 1:10. Sessions will include moderate-intensity aerobic activities such as jumping, skipping and jogging. Participants will exercise at approximately 50% to 60% of their estimated maximum heart rate, calculated as 220 minus age, and their exercise intensity will be monitored using a Polar heart-rate monitor. Participants in control schools will receive no additional physical activity programme during the 12-week period and will continue their regular school routines and usual practices. All participants will complete assessments at baseline, immediately after the 12-week intervention, 3 months after the intervention and 12 months after the intervention. Outcome assessors will be blinded to school allocation and participants’ diagnostic group. Participants will be involved in the study for approximately 15 months. Teachers in intervention schools will also receive two 3-hour training workshops, a training manual and access to educational materials and instructional videos to support future programme delivery.
Intervention type	Behavioural
Primary outcome measure(s)	Psychological ill-being (stress, anxiety, depression) measured using the Chinese Depression Anxiety Stress Scale-21 (DASS-21) at baseline (T0), immediately after the 12-week intervention (T1), 3 months after the intervention (T2) and 12 months after the intervention (T3) Stress biomarker (salivary cortisol levels) measured using cortisol ELISA kit at baseline (T0), immediately after the 12-week intervention (T1), 3 months after the intervention (T2) and 12 months after the intervention (T3) Psychological well-being (self-concept) measured using the Physical Self-Description Questionnaire (PSDQ) at baseline (T0), immediately after the 12-week intervention (T1), 3 months after the intervention (T2) and 12 months after the intervention (T3)
Key secondary outcome measure(s)	Aggression measured using the Chinese 12-item Aggression Questionnaire (AQ) at baseline (T0), immediately after the 12-week intervention (T1), 3 months after the intervention (T2) and 12 months after the intervention (T3) Suicidal ideation measured using the Chinese version of the Reynolds Suicidal Ideation Questionnaire (SIQ) at baseline (T0), immediately after the 12-week intervention (T1), 3 months after the intervention (T2) and 12 months after the intervention (T3)
Completion date	31/12/2023

Eligibility

Participant type(s)
Age group	Mixed
Lower age limit	12 Years
Upper age limit	18 Years
Sex	All
Target sample size at registration	200
Total final enrolment	170
Key inclusion criteria	1. Aged 12 to 18 years at enrolment and attending Forms 1 to 6. 2. Attending one of the participating co-educational mainstream secondary schools in Hong Kong. 3. Has a clinical diagnosis of autism or ADHD, including a possible co-occurring diagnosis, according to DSM-5 criteria. Confirm the acceptable diagnostic documentation and who verifies eligibility. 4. Provides participant assent and consent and has written parent or guardian consent in accordance with the approved ethics documents.
Key exclusion criteria	1. Neurological impairment that prevents or materially limits safe participation in the intervention or assessments. 2. Intellectual impairment that prevents participation under the protocol. 3. Any other medical condition that limits participation in the physical activity programme.
Date of first enrolment	15/05/2021
Date of final enrolment	31/12/2022

Locations

Countries of recruitment

Hong Kong

Study participating centre

Department of Sports Science and Physical Education, The Chinese University of Hong Kong

Shatin, New Territories, Hong Kong SAR, China.
Hong Kong
000000
Hong Kong

Results and Publications

Individual participant data (IPD) Intention to share	No

Editorial Notes

27/08/2026: Study's existence confirmed by the Chinese University of Hong Kong.