Studies have shown that children with ASD simultaneously have deficits in overall executive function and impairments in basic motor skills, which have a negative impact on cognitive and social all-round development. In recent years, intervention measures for the motor skills of children with ASD have gradually developed. However, based on the existing literature, there is still a lack of recommendations for sports training at present. The sustained effect of exercise intervention training on the core symptoms of ASD remains unclear. In terms of executive function, there are relatively few studies on the executive function of preschool children. The impact of motor training on working memory in school-aged children is still inconsistent. Furthermore, the connection characteristics of different brain regions in children with ASD after physical training remain unclear. This study will include 70 children with ASD aged 3 to 9 years for a multicenter randomized controlled trial (RCT). These children will be randomly assigned to the intervention group (Child-Parent-Trainer program) and the control group (regular physical education program) for 12 weeks, 5 days/week, 60 minutes/day training. Children's core symptoms, executive function, child/family quality of life, and functional near-infrared spectroscopy (fNIRS) were assessed at baseline (training weeks 0) and endpoints (training weeks 13 and 17), respectively. To verify the improvement effect of this exercise program on the autism severity, core symptoms and executive functions of children with ASD, as well as its impact on family quality of life. Furthermore, through fNIRS for monitoring changes in brain function, the potential neural physiological mechanisms will be explored.

1. Procedures. The children in the group are randomly divided into a intervention group and a control group. The children will be trained for 12 weeks (5 days/week, 60 minutes/day) and the children will be evaluated for the severity of autism, core symptoms, executive function, child/family quality of life, and fNIRS at training weeks 0, 13, and 17, respectively.
2. Demographic questionnaire and clinical data. The demographic questionnaire is completed by the child's primary caregiver, detailing child's name, gender, date of birth, height, weight, heart rate. Clinical data will be ascertained from the medical records, including information about DSM-5 diagnosis and comorbid conditions.
3. Sample size. This study is a randomized controlled trial. The proposed sample size is based on using the sample size formula, which compares the two sample means, . Where, tα is the standard normal difference corresponding to the level, taking α=0.05 and tα=1.96; tβ is the u value corresponding to the probability β of type II error, taking β=0.10 and tβ=1.28; σ is the estimate of the population standard deviation; δ is the allowable error, the difference between two population means. According to literature review, taking the adjustment ability in executive function as the main observation index, it is calculated that δ/σ =0.84. The sample size of intervention group and control group was 30 children, respectively. Considering the sample loss rate of 15%, the two groups are finally determined to be 35 children respectively.
4. Statistical analysis. SPSS 25.0 software (SPSS Inc) was used for statistical analysis for the scale data, including core symptoms and executive function, and the data were expressed as (M±SD). The scales scores and demographic variables of both groups of children will be compared using independent samples t-tests. Differences between baseline and 1 week and 1 month after exercise will be analysed using a repeated measures F-test. All statistical analyses were conducted with a statistical threshold P-value of <0.05. The data collected through fNIRS will be performed via NirSpark analysis software. The general linear model (GLM) will be applied to integrate task effects and assess activation in relevant brain regions. To analyze the rsFC of brain in children with ASD before and after the exercise intervention, the FC_NIRS toolbox is used.
5. Ethical matters and data protection. The patients participated in the study will sign the informed consent (obtained from the guardian). And this study was approved by the local ethics committee. Patient's name will be abbreviated and the research data will be assigned a code then to provide to the researcher. The authorization from parents on the patient's health information remains valid until the study is completed. After that, researchers will delete private information from the study record.

Inclusion Criteria:

• Age: 3-9 years old.
• Meet the Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition (DSM-5) diagnostic criteria for ASD, And hold a certificate of ASD diagnosis issued by a Tertiary A hospital.
• Borderline/normal intelligence or mild intellectual disability.
• No serious behavior or emotional problems.
• Able to simply ask and answer questions.
• Be able to proactively express the need to use the toilet.
• There are no physical impairments that affected participation in physical activities, and participants are able to cooperate to complete the intervention.
• Informed parental consent.

Exclusion Criteria:

• Vision/ hearing disorders, schizophrenia, emotional disorders, mental retardation, Rett syndrome and other developmental disorders.
• Medical conditions that limit the ability to be physically active, such as asthma, epilepsy, heart disease, and the acute phase after a fracture.
• History of head trauma, physical disability, major organ disease, or severe musculoskeletal injury in the past two years.
• Those who have participated in physical exercise regularly within the last 6 months.
• Participants who changed treatment intervention midway after inclusion.
• Unable to cooperate with persistent completion of intervention.

Data is confidential during the study.